Time-evolving genetic networks reveal a NAC troika that negatively regulates leaf senescence in <i>Arabidopsis</i>

Kim, Hyo Jung,Park, Ji-Hwan,Kim, Jingil,Kim, Jung Ju,Hong, Sunghyun,Kim, Jeongsik,Kim, Jin Hee,Woo, Hye Ryun,Hyeon, Changbong,Lim, Pyung Ok,Nam, Hong Gil,Hwang, Daehee National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.21

<▼1><P><B>Significance</B></P><P>Leaf senescence is regulated in a complex manner, involving time-dependent interactions with developmental and environmental signals. Genetic screens have identified key regulators of senescence, particularly late-stage senescence regulators. Recently, time-course gene-expression and network analyses, mostly analyses of static networks, have predicted many senescence regulators. However, senescence is defined by time-evolving networks, involving the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks of NAM/ATAF/CUC (NAC) transcription factors, central regulators of leaf senescence in <I>Arabidopsis</I>, via time-course gene-expression analysis of NACs in their mutants. These time-evolving networks revealed a unique regulatory module of NACs that controls the timely induction of senescence-promoting processes at a presenescent stage of leaf aging.</P></▼1><▼2><P>Senescence is controlled by time-evolving networks that describe the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks for NAM/ATAF/CUC (NAC) transcription factors in <I>Arabidopsis</I> during leaf aging. The most evident characteristic of these time-dependent networks was a shift from positive to negative regulation among NACs at a presenescent stage. ANAC017, ANAC082, and ANAC090, referred to as a “NAC troika,” govern the positive-to-negative regulatory shift. Knockout of the NAC troika accelerated senescence and the induction of other <I>NAC</I>s, whereas overexpression of the NAC troika had the opposite effects. Transcriptome and molecular analyses revealed shared suppression of senescence-promoting processes by the NAC troika, including salicylic acid (SA) and reactive oxygen species (ROS) responses, but with predominant regulation of SA and ROS responses by ANAC090 and ANAC017, respectively. Our time-evolving networks provide a unique regulatory module of presenescent repressors that direct the timely induction of senescence-promoting processes at the presenescent stage of leaf aging.</P></▼2>

간 세포암에서 VEGF, TGF-β1, b-FGF 발현의 의의

김성용,남충현,주종우,채만규,백무준,이문수,김형철,안현철,김홍수,김창진,김창호 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Purpose: Angiogenesis is important for the proliferation and the metastasis of solid tumors. The growth of a solid tumor is widely recognized to depend on the process of neovascularrozation. Without angiogenesis, tumors cease to grow beyond even a few milimeters in diameter. It has been shown that tumor vascular density is an independent prognostic marker in several types of human tumors and is known to correlate with poor prognosis. To date, many angiogenic factors have been identified, such as transforming growth factor-α(TGF-α), transforming growth factor-β(TGF-β), fibroblast growth factor family(FGF), vascular endothelial growth factor(VEGF), platelet derived endothelial cell growth factor(PD-ECGF), tumor necrosis factor-α(TNF-α), and angiogenin. Hepatocellular carcinoma(HCC) is the second most common tumor in Korean males and is known as a typical hypervascular tumor with frequent portal vein invastion. The authors identified the expreesion of VEGF, TGF-β1, and b-FGF in HCC specimens and evaluated the relationship between these growth factors and the clinicopathologic characteristics of HCC. Method: We reviewed the medical records of 30 patients who were diagnosed as hepatocellular carinoma treated with hepatic resection between January 1994 and December 1998 in Soonchunhyang University Chunan Hospital. The selection of the cases was decided according to the condition of paraffin block fixation. The prognostic factors such as age, sex, tumor size, concentration of serum α-fetoprotein, presence of liver cirrhosis, presence of tumor emboli in portal vein, TMN stage, amount of transfusion during the operation, hepatitis B virus(HBV) infection, and Edmonson-Steiner(E-S) grade were investigated. Relationship between the prognostic factors and the immunopathologic expression of the TGF-β1, b-FGF, and VEGF was examined. Result: Thirty patients (24 males, 6 females) were included in the current study. The patient's mean age was 50.6 years and the age ranged from 36 to 65 years. The mean size of the tumor was found to be 5.2cm. All the patients were follewed up for 7 to 63 months. Child's classification A patients were 23(76.7%)cases, B patients were 7(23.3%)cases, and C was none. Immunohistochemical staining of HCC tumor mass in VEGF expression patients were 17(56.7%), b-FGF expression patients were 10(33.3%), and TGF-β1 expression patients were 10(33.3%). VEGF expression or more than one positive expression among the three factors correlated with tumor size and the stage of HCC but did not correlated with other clinicopathological characteristics. TGF-β1 and b-FGF did not correlate with any clinicopathological characteristics. Conclusion: The results suggest that the expression of VEGF or more than one positive expression among the three factors in HCC cells may be a significant prognostic factor of HCC.

Electropulsing Treatment on Enhancement of Electrical Conductivity of Screen-Printed Ag Wire

Ju‑Won Park,Howook Choi,Hwangsun Kim,Simoon Sung,Hye‑Jin Jeong,Il Kim,Jaeseok Gong,Sung‑Tae Hong,Heung Nam Han 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

The effect of high electric current density on the sintering of Ag wires manufactured by screen printing is evaluated throughelectrical resistivity analysis and microstructure observation. Different forms (continuous and pulsed) of electric currentwith different current densities are applied to the specimens. Conventional heat treatment is also performed as a controlgroup to examine the athermal effect of electropulsing treatment. Compared to the conventional heat treatment, the resistivityis reduced more under the electropulsing treatment with continuous current for the same temperature and treatment time.Also, the process time of electropulsing treatment can be reduced by applying a pulse form of high density current insteadof continuous current without losing the benefit of enhanced reduction of resistivity. The microstructural observationsobtained from high angle annular dark field scanning transmission electron microscope and a digital precession instrumentclearly show that necking connecting the crystals is formed more firmly under electric current. In addition, the temperaturechange of Ag wire and substrate is calculated according to the change of the resistivity when the electric current is appliedto confirm the reliability.

항갑상선제로 치료한 그레이브스병 환자의 관해예측인자

남일송,윤여일,김선규,김용현,이주영,목지오,윤석기,김철희,김영선,변동원,서교일,유명희 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background: Most cases of Graves' disease have been treated by antithyroid drugs in Korea. The major drawbacks of antithyroid drugs are the relative high rate of relapse and the inconvinience of long term therapy. Measurement of TBII and TRH stimulation test have been considered as the most reliable tests predicting relapse, but the predictive power is not high enough to use in clinical situation. This study was performed to find good prognostic indicators in Graves' disease patients after the discontinuation of antithyroid drug therapy. Subjects and methods : We restrospectively evaluated 96 patients with Graves' disease who showed normal TRH test at the end of antithyroid drug therapy and were followed for more than one year. Serum T3, T4, T3/T4 ratio, TBII, Anti-TPO Ab and TGAb levels were measured at the time of diagnosis and at the end of therapy. Two to three months after withdrawal of antithyroid medication, serum TSH and free T3 responses to TRH were examined. These parameters were compared between the relapse group and the remission group. Results : Among the 96 patients, 22 patients(22.9%) relapsed(Group Ⅱ) and 74 patients(77.1%) remained in remmision(Group Ⅰ). No significant difference was observed between the relapse and the remission group in clinical parameters, serum T3, T4, TSH, T3/T4 ratio, TBⅡ and Anti-TPO Ab determined before and after treatment. Serum TSH and free T3 levels measured after TRH stimulation were also similar in both groups. Serum TGAb levels determined at the end of treatment were significantly higher in the remission group(p<0.05). Relapse following the discontinuation of therapy occured within 24 months in 72.7% of the relapsed cases. After 24 months, relapse rate was reduced significantly. Conclusion : These results suggest that high serum TGAb levels could be a favorable prognostic indicator for the long term remission of Graves' disease treated with antithyroid drugs, and may suggest that Hashimoto's thyroiditis is combined with Graves' disease in those patients.

폐암환자 말초혈액의 자연살해세포 표현형(Natural Killer Cell Phenotypes)과 T임파구 아형 (T-Cell Subsets)의 의의

남재만,서지원,김남재,김주옥,김선영 충남대학교 의과대학 지역사회의학연구소 1989 충남의대잡지 Vol.16 No.2

The authors studied the NK cell phenotype and T cell subsets in 36 patients with bronchogenic carcinoma and 11 healthy controls. The results were summarized as follows. 1. The percentage of lymphocyte and total lymphocyte counts significantly decreased in cancer patients compared to normal control(p<0.05). 2. The OKT4^+(%) was significantly decreased in patients according to celltype (especially squamous cell cancer, adenocarcinoma and large cell carcinoma) and extended stage(stageⅢ) (p<0.05), but no change in limited stage(stage Ⅰ&Ⅱ). 3. The OKT8^+(%) and OKT4^+ ratio were not significantly changed in cancer patient. 4. According to cell type, there was no significant difference of NK cell phenotype between cancer patients and controls. 5. According to stage, there was no significant difference of NK cell phenotype between cancer patients and controls. 6. There was no significant difference of NK cell phenotype in cancer patients compared to normal controls. We concluded that NK cell phenotype had no significant difference between cancer patients and healthy controls. Further studies (including NK cell activity or other function tests of lymphocyte) are needed to analyze the roles of immunologic responses in patients with lung cancer.

Effects of Phenytoin and Diazepam on the Seizure Activity in the Cortical Dysplasia Animal Models

Kim, Si-Hyung,Choi, In-Sun,Cho, Jin-Hwa,Park, Eun-Ju,Jang, Il-Sung,Choi, Byung-Ju,Kim, Hyun-Jung,Kim, Young-Jin,Nam, Soon-Hyeun The Korean Academy of Oral Biology 2006 International Journal of Oral Biology Vol.31 No.2

Dysplasia-associated seizure disorders are markedly resistant to pharmacological intervention. Relatively little research has been conducted studying the effects of antiepileptic drugs(AEDs) on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate(MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of AEDs in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injucted control animals. Field potential recordings were used to monitor amplitude and numbers population spikes, and paired pulse inhibition in response to stimulation of commissural pathway. Two commonly used AEDs were tested: diazepam 5, 2.5mg/kg;phenytoin 40, 60mg/kg. Diazepam(DZP) and phenytoin(PHT) reduced the amplitude of population spike in control and MAM-exposed rats. However, the amplitude of population spike was nearly eliminated in control rats as compared to the MAM-exposed rats. Pharmaco-resistance was tested by measuring seizure latencies in awake rats after pilocarpine administration(320mg/kg, i.p.) with and without pretreatment with AEDs. Pre-treatment with PHT 60 mg prolonged seizure latency in control rats, but not in MAM-exposed animals. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard AEDs assessed in vivo. These data suggest that animal model with cortical dysplasia can be used to screen the effects of potential AEDs.

GPS에 의한 도로변형량 측정 적용

김남식(Kim Nam-Sik),서동주(Seo Dong-Ju),노태호(Roh Tea-Ho) 한국지적정보학회 2001 한국지적정보학회지 Vol.3 No.-

본 연구에서는 향후 폭넓게 활용될 GPS에 의하여 도로의 변형량을 측정하고, 그 결과를 검증하기 위하여 EDM으로 관측한 결과와 비교하였으며, 관측대상지역은 경상남도 일원의 국도를 산정하였다. 첫째로 GPS의 측정 Mode중 Rapid Static Mode로 측정한 결과와 EDM으로 관측한 결과를 비교하면 수평방향 변위 평균 1.9~2.3㎝, 수직방향변위 평균 3.2㎝교차가 있었다. 둘째로 GPS 관측방법중 Static Mode 는 ±(3~7)㎜, Rapid Static Mode는 ±(6~7)㎜, Stop and Go Mode는 ±(121~226)㎜ 크기의 표준편차가 있는 것으로 나타났다. 따라서 Rapid Static Mode는 도로변형량 측정에 이용할 수 있는 방법이다. 셋째로 도로시공시 변형이 우려되는 곳에 이러한 간격으로 검사점을 설치하고, GPS에 의한 초기값을 관측해 두면, 시간경과에 따른 도로의 3차원 변형량을 비교적 정확하게 관측할 수 있다. This research was to analyze the road deformation surveying by GPS(Global Positioning System), and accuracy and usefulness of GPS was founded out excellent in the road deformation surveying. To execute this study, the national road in Kyungsang Nam-Do was surveyed, and analyzed the observation data. Results form this study are as follows, First, Compared GPS data with EDM data, the average horizontal discrepancy was 1.9~2.3㎝, the average vertical discrepancy was 3.2cm. Second, In GPS surveying mode, the standard deviation computed from "Static Mode" was ±(3~7)㎜, from "Rapid Static Mode" was ±(6~7)㎜, and from "Stop and Go Mode" was ±(121~226)㎜. Therefore "Rapid Static Mode" is also available for road deformation surveying. Third, In case of road construction, monitoring point were set up at regular intervals and checked a initial value by GPS, the 3-dimensional road deformation with lapse of time could be surveying correctly.

규범활성화 모델(NAM)과 계획된 행동이론(TPB)을 통합 적용한 관광자의 로컬 크리에이터 관광 콘텐츠 소비 행동의도에 관한 연구 - 지각된 가치의 조절효과 -

허욱(Heo, Wook),박은주(Park, Eun-Ju),김남조(Kim, Nam-Jo) 한양대학교 관광연구소 2025 관광연구논총 Vol.37 No.1

This study examines the structural relationship between tourists’ consumption intentions for local creator tourism content by integrating the Norm Activation Model (NAM) and the Theory of Planned Behavior (TPB), while also assessing the moderating effect of perceived value. An online survey was conducted with 254 tourists who had consumed such content. The analysis revealed that attitude, subjective norm, and perceived behavioral control positively influenced behavioral intention. In the NAM framework, awareness of consequences positively influenced ascription of responsibility, which in turn positively affected personal norm; however, personal norm did not significantly impact behavioral intention. Additionally, awareness of consequences positively influenced attitude, and subjective norm positively influenced personal norm. Among the dimensions of perceived value, functional value moderated the relationships between (1) subjective norm and behavioral intention, (2) awareness of consequences and attitude, and (3) subjective norm and personal norm. This study confirms the applicability of the integrated NAM-TPB model in explaining tourists’ consumption behavior of local creator tourism content. It also establishes a theoretical foundation for future research by validating the moderating role of perceived value. As a policy implication, the findings suggest strategies to enhance market competitiveness and reinforce awareness of consequences and subjective norms in developing policies to support local creators.

기상 증착된 비정질 실리콘 카바이드 박막질의 기판 온도 의존성

김주영,이백우,남호석,권동일 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.3

The dramatic variations in structure and internal stress in an amorphous silicon carbide film (a-SiC) induced by forming process have been reported extensively. Vapor-depositions of a-SiC film were simulated by molecular dynamics simulation employing the Tersoff potential. To understand effect of substrate temperature that is one of the most important factors involved in the changes in structure and intrinsic stress, the vapor-depositions at various substrate temperatures (500-2500 K) were performed. Then, the MD simulations of cooling to 298 K were carried out. For both cooled and as-deposited a-SiC films, the analyses of structure and internal stress with deposition process parameters entailed the calculation of density, chemical order, and in-plane stress [(σ_(xx)+σ_(yy))/2].

스모그 챔버에서 수분 반응에 의한 대기 에어로졸의 생성 및 성장

김민철,배귀남,문길주,박주연 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.2

Aerosol formation and growth by water vapor reactions were investigated in a 2.5-㎥ indoor smog chamber filled with the unfiltered ambient air. The relative humidity of test ambient air was elevated at 59~64% or 84~88% by adding water vapor. The aerosol number size distribution and the concentrations of O₃, NO, NO₂, and SO₂ were measured during the experiments. The O₃, and NO₂ gases were well reacted with the water vapor at high relative humidity of 84~88%, and the reaction rates of these gases seemed to be decreased at low relative humidity of 59~64%. The formation and condensational growth phenomena of ambient aerosols by water vapor reactions were observed in a Teflon bag, depending strongly on the initial particle size distribution. The water vapor reactions might be affected by the contents of oxidants produced by photochemical reactions under sunlight.