• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6021-6024
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• 2014

Background: The STK15 gene located on chromosome 20q13.2 encodes a centrosome-associated kinase critical for regulated chromosome segregation and cytokinesis. Recent studies have demonstrated STK15 to be significantly associated with many tumors, with aberrant expression obseved in many human malignancies. The purpose of this study was to investigate expression of STK15 in esophageal squamous cell carcinomas (ESCCs) in a Mongolian population. Methods: Two non-synonymous single nucleotide polymorphisms in the coding region of STK15, rs2273535 (Phe31Ile) and rs1047972 (Val57Ile) were assessed in 380 ESCC patients and 380 healthy controls. We also detected STK15 mRNA expression in 39 esophageal squamous cell carcinomas and corresponding adjacent tissues by real time PCR. Results: rs2273535 showed a significant association with ESCC in our Mongolian population (rs227353, P allele = 0.0447, OR (95%CI) = 1.259 (1.005~1.578)). Real time PCR analysis of ESCC tissues showed that expression of STK15 mRNA in cancer tissues was higher than in normal tissues (p = 0.013). Conclusions: Our study showed that functional SNPs in the STK15 gene are associated with ESCC in a Mongolian population and up-regulation of STK15 mRNAoccurs in ESCC tumors compared adjacent normal tissues. STK15 may thus have an important role in the prognosis of ESCC and be a potential therapeutic target.

• 한국전자파학회논문지
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• 제16권7호
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• pp.720-731
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• 2005

본 논문에서는 위성 발사체와 같이 전기적으로 큰 원통 도체 위에 전기적으로 작은 역 F 안테나들이 장착된 경우에 대해 방사 패턴을 실험적으로 고찰하였다. 먼저 모멘트 법(MOM: Method Of Moment)과 상용 툴(tool)인 HFSS(High Frequency Structure Simulator)를 이용하여 방사 패턴을 구하고 이의 결과를 실험 결과와 비교 분석하였다. 특히 원통 도체가 전기적으로 큰 경우 안테나 근방의 접지면 일부분만을 고려하여 원통 도체의 크기가 방사 패턴에. 미치는 영향을 고찰하였다. 다음 역 F 안테나가 원통 도체에 1개, 2개 장착된 경우에 대해 방사패턴을 모멘트 법, HFSS를 이용하여 구하고 고찰하였는데 이의 결과와 실험 결과가 서로 잘 일치함을 확인하였다.

• Journal of Radiation Protection and Research
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• 제40권3호
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• pp.168-173
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• 2015

이 연구에서 후쿠시마 원전 폭발과 같은 사고 발생 시 방사선이나 방사성 핵종에 의한 생물학적 영향을 평가할 수 있는 야생 동물지표로서 성축 등줄쥐(A. a. coreae) 활용 가능성을 평가하였다. 이 연구를 위하여 야외 채집한 등줄쥐를 실험실에서 교배하고 생산된 새끼가 약 40주령이 되었을 때 털 색깔, 외부형태, 두개골, 치아 특성을 관찰하고 분류학적 특성을 정리하였다. 방사선에 대한 신체 반응도를 평가하기 위하여 방사선 조사(0, 0.5, 1, 2 Gy) 24시간 후에 장기무게를 관찰한 결과 흉선만이 감소하였다. 방사선에 민감한 장기 가운데 하나인 비장 세포고사는 선량에 비례하여 증가하였지만, 0.5 Gy 조사된 개체에서는 감소하였다. 앞으로 야생 등줄쥐 신체 장기별 방사선 민감도 차이를 세포 및 분자생물학적 수준에서 해석함으로써 방사선 피폭 사고시 신체영향을 평가할 수 있는 방법론 도출이 가능할 것이라 생각된다.

• 천문학회지
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• 제42권1호
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• pp.1-7
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• 2009

The e-CALLISTO is a global network of frequency-agile solar radio spectrometers that was constructed in a collaboration between Swiss Federal Institute of Technology Zurich (ETH Zurich) and local host institutes. It is intended to monitor solar radio bursts 24 hours a day in frequency range between 45 MHz and 870 MHz. One of e-CALLISTO spectrometer was installed at Korea Astronomy and Space Science Institute (KASI) in 2007 October. The spectrometer gets signals from a horizontally polarized log-periodic antenna mounted on an automatic Sun-tracking system. Tracking status and data are monitored in Space Weather Monitoring Laboratory (SWML) of KASI in real time, and flare time data are transferred to ETH Zurich data archive daily. Using this spectrometer we obtained a couple of type II solar radio bursts on 2007 December 31, and found that these bursts are associated with a CME which occurred on the east limb.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권1호
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• pp.37-37
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• 2004

It is well known that solar activity such as coronal mass ejections(CMEs) and flares is a direct driver of space weather. In this talk, we introduce its main physical characteristics and physical connections among CMEs(or flares) -Interplanetary(IP) shocks - interplanetary CMEs (or magnetic clouds) - geomagnetic storms. Specifically, solar activity is discussed in terms of space weather scales (R:Radio Blackout, S: Solar Radiation Storms, G: Geomagnetic Storms). (omitted)

• 천문학회지
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• 제36권spc1호
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• pp.63-73
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• 2003

Solar flares present a number of radiative characteristics indicative of kinetic processes of high energy particles. Proper understanding of the kinetic processes, however, relies on how well we can separate the acceleration from transport characteristics. In this paper, we discuss microwave and hard X-ray bursts as a powerful tool in investigating the acceleration and transport of high energy electrons. After a brief review of the studies devoted to the kinetic process of solar flare particles, we cast them into a simple formulation which allows us to handle the injection, trap, and precipitation of flare electrons self-consistently. The formulation is then taken as a basis for interpreting and analyzing a set of impulsive and gradual bursts occurred on 2001 April 6 observed with the Owens Valley Solar Array, and HXT/WBS onboard Yohkoh satellite. We quantify the acceleration, trap, and precipitation processes during each burst in terms of relevant time scales, and also determine ambient density and magnetic field. Our result suggests that it should be the acceleration property, in particular, electron pitch angle distribution, rather than the trap condition, that is mainly responsible for the distinctive properties of the impulsive and gradual flares.

• 천문학회지
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• 제36권spc1호
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• pp.29-36
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• 2003

Quiescent solar radiation, at microwave spectral regime, is dominated by gyroresonant and thermal Bremsstrahlung radiations from hot electrons residing in solar active region corona. These radiations are known to provide excellent diagnostics on the coronal temperature, density, and magnetic field, provided that spatially resolved spectra are available from observations. In this paper we present an imaging spectroscopy implemented for a bipolar active region, AR 7912, using the multifrequency interferometric data from the Owens Valley Solar Array (OVSA), as processed with a new imaging technique, so-called Spatio-Spectral Maximum Entropy Method (SSMEM). From the microwave maps at 26 frequencies in the range of 1.2-12.4 GHz at both right- and left-circular polarizations, we construct spatially resolved brightness spectra in every reconstructed pixel of about 2 arcsec interval. These spectra allowed us to determine 2-D distribution of electron temperature, magnetic field of coronal base, and emission measure at the coronal base above the active region. We briefly compare the present result with existing studies of the coronal active regions.

• Journal of Astronomy and Space Sciences
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• 제5권2호
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• pp.123-127
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• 1988

한 전파원으로부터 발생되는 전자파가 태양풍 내의 플라즈마 요동에 따른 굴절 효과때문에 매질 내에서 교란을 받는다. 이 논문에서는 지상 관측을 통하여 이러한 교란인 행성간 공간섬광을 측정하여 지구와 태양 사이의 행성간 공간에서 일어나는 태양풍 활동을 조사하려는 연구의 이론을 제시할 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제24권5호
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• pp.413-422
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• 2020

Delphinidin is a major anthocyanidin compound found in various vegetables and fruits. It has anti-oxidant, anti-inflammatory, and various other biological activities. In this study we demonstrated the anti-cancer activity of delphinidin, which was related to autophagy, in radiation-exposed non-small cell lung cancer (NSCLC). Radiosensitising effects were assessed in vitro by treating cells with a subcytotoxic dose of delphinidin (5 μM) before exposure to γ-ionising radiation (IR). We found that treatment with delphinidin or IR induced NSCLC cell death in vitro; however the combination of delphinidin pre-treatment and IR was more effective than either agent alone, yielding a radiation enhancement ratio of 1.54 at the 50% lethal dose. Moreover, combined treatment with delphinidin and IR, enhanced apoptotic cell death, suppressed the mTOR pathway, and activated the JNK/MAPK pathway. Delphinidin inhibited the phosphorylation of PI3K, AKT, and mTOR, and increased the expression of autophagy-induced cell death associated-protein in radiation-exposed NSCLC cells. In addition, JNK phosphorylation was upregulated by delphinidin pre-treatment in radiation-exposed NSCLC cells. Collectively, these results show that delphinidin acts as a radiation-sensitizing agent through autophagy induction and JNK/MAPK pathway activation, thus enhancing apoptotic cell death in NSCLC cells.

• 대한방사선기술학회지:방사선기술과학
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• 제14권2호
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• pp.9-14
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• 1991

Chest radiograms obtained by using Fuji Computed Radiography(FCR) system were compared to conventional film/screen radiograms. The FCR images showed better image quality in diagnostic informations than the conventional chest images. In FCR, the radiation exposure to patient for chest examination could be reduced up to one tenths of conventional chest examination. The main advantages or FCR were considered to depend on the contrast processing and frequency processing properties. The use of FCR in clinical work may improve both diagnostic quality and radiation exposure.