• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.624-627
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• 2003

Benzo[a]pyrene (B[a]P) is an environmental pollutant that has been implicated in carcinogenesis. Saccharomyces cerevisiae was treated with B[a]P, and the responses of its cytochrome P450 (CYP) enzyme and DNA-damage checkpoint genes were examined through gene expression profiles using a reverse transcription polymerase chain reaction (RT-PCR). The DNA-damage checkpoint genes tested were the chk1 and pds1 genes, involved in a metaphase arrest, the swi6 gene targeted by G1 arrest, the pol2 gene related to S phase arrest, and the cln2 gene encoding a cyclin protein, all of which are based on rad9 and rad24. Among these genes, no noticeable effect was found when the cells were exposed to various concentrations of B[a]P. However, the transcriptional activity of CYP51 was significantly different when the cells were exposed to B[a]P. Accordingly, the present results indicate that cytochrome P450 plays a more significant role than DNA-damage checkpoint genes in the response of S. cerevisiae to B[a]P.

• Korean Journal of Optics and Photonics
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• v.12 no.4
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• pp.300-304
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• 2001

We suggest a method to measure and correct bending deformation in piezoelectric ceramics displacement. The angle and direction of the bending deformation are measured by monitoring the position of a laser beam reflected on a mirror which is attached to the piezoelectric ceramics with the uncertainty of the angle measurement of $0.36\mu$rad. We divided the electrode of a piezoelectric ceramic into 3 parts and connected 3 capacitors to each electrode in order to apply different voltage to each electrode with one voltage supplier. The deformation was corrected by adjusting the capacitance of each capacitor and was reduced to 6.3%, comparing to the uncorrected case. By using this corrected piezoelectric ceramic to modulate the length of the ringdown cavity, the fluctuation of the decay time caused by the change in optic axis of the cavity was removed.emoved.

• Korean Journal of Optics and Photonics
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• v.22 no.1
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• pp.1-4
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• 2011

A new fabrication technique of long-period fiber gratings with periodically surface-etched structures is proposed. Transmission characteristics of the periodically surface-etched long-period fiber gratings are improved by changing strain because of variation of coupling strength between the core and the cladding modes. The sensitivities of the periodically surface-etched long-period fiber gratings to strain, torsion, and ambient refractive index were measured. The strain and the torsion sensitivities were measured to be $-0.033\;dB/\mu\varepsilon$ and -1.30 nm m/rad, respectively. The ambient index sensitivity was measured to be -31.33 nm/RIU from a range from 1.33 to 1.42.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.4
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• pp.281-287
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• 2016

In this paper, we propose a novel compact surveillance throwing robot which has an omnidirectional shock absorption mechanism and an active control part of wheel treads to stabilize the dynamic posture of a miniature sphere type throwing robot. This throwing robot, which weighs 1.14kg and is 110mm in height, is designed in a spherical shape to be easily grabbed for throwing. Also, the omnidirectional shock absorbing aspect is designed using several leaf springs connected with inner and outer wheels. The wheel treads control part consists of a link mechanism. Through the field experiments, this robot is validated to withstand higher than 17Ns of omnidirectional impulse and increase the stabilized max speed three times from 11 rad/s to 33rad/s by increasing wheel treads.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.512-518
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• 2018

This article measured and analyzed the indoor radon concentrations at one university building in Gyeongju, Republic of Korea, to investigate if there is any relationship between earthquakes and indoor radon concentration. Since 12 September 2016, when two 5.1 and 5.8 magnitude earthquakes occurred, hundreds of aftershocks affected Gyeongju until January 2017. The measurements were made at the ground floor of the Energy Engineering Hall of Dongguk University in Gyeongju over a period between February 2016 and January 2017. The measurements were made with an RAD7 detector on the basis of the US Environmental Protection Agency measurement protocol. Each measurement was continuously made every 30 minutes over the measurement period every month. Among earthquakes with 2.0 or greater magnitude, the earthquakes whose occurrence timings fell into the measurement periods were screened for further analysis. We observed similar spike-like patterns between the indoor radon concentration distributions and earthquakes: a sudden increase in the peak indoor radon concentration 1-4 days before an earthquake, gradual decrease before the earthquake, and sudden drop on the day of the earthquake if the interval between successive earthquakes was moderately longer, for example, 3 days in this article.

• Fisheries and Aquatic Sciences
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• v.22 no.8
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• pp.18.1-18.5
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• 2019

The development of sex-specific genetic assays in a species provides both a method for identifying the system of sex determination and a valuable tool to address questions of conservation and management importance. In this study, we focused on the identification of single nucleotide polymorphisms (SNPs) that differentiate genetic sex in burbot Lota lota. Burbot are the only true freshwater representative of the cod family and a species of conservation and management importance throughout Eurasia and North America. To identify sex-specific SNPs, we utilized restriction site-associated DNA sequencing (RADseq) to interrogate thousands of SNPs in burbot samples of known phenotypic sex. We discovered 170,569 biallelic SNPs, none of which fit the pattern expected under female heterogamety. However, we identified 22 SNPs that fit the pattern expected under male heterogamety (males heterozygous XY, females fixed XX) and, from these, developed two genetic assays that robustly (~ 97% genotyping success) and accurately (> 99% correct) sexed burbot samples. These sex-specific genetic assays will benefit growing conservation aquaculture programs for this species and allow future assessments of sex-specific migration, growth, and mortality.

• Nuclear Engineering and Technology
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• v.8 no.2
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• pp.89-99
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• 1976

The grafting of acrylic acid in aqueous solution to polyvinyl chloride fibers tab been studied in the presence of ferrous, ferric, and cupric salts, The mutual irradiation technique was adopted using a Co-60 source or a Van do Graaff accelerator. The grafting and homopolymerization were suppressed by the cations. Particularly the grafting was suppressed by the cations in the following order of effectiveness : $Cu^{2+}$>$Fe^{2+}$>$Cu^{3+}$. The rate of grafting (in %/hr) was proportional to the 0.76th power of the dose rate over the range from 8.5f $10^3$ rad/hr to $1.4\times10^5$ rad/dr. The apparent activation energy for the grafting was determined to be 6.1 Kcal/mole between $25^{\circ}$ and $75^{\circ}C$ for the mixture of AA-HaO-$(CH_2Cl)_2$, containing Mohr's salt, $4\times10^{-3}$ mole/l. The increase of the grafting was observed when total dose and dose intensity were raised, or when ethylene dichloride as a swelling agent was saturated in the monomer mixture. The grafted polyvinyl chloride fibers showed considerable improvement in moisture regain, heat shrinkage, and melting properties, but tensile properties were not significantly affected by grafting.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.54-60
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• 1995

Medical Internal Radiation Dose(MIRD) schema was developed for calculating the absorbed dose from the administered radiopharmaceuticals. With the biological distribution data and the physical properties of the radionuclide we can estimate the absorbed dose by the MIRD schema. For the thyroid cancer patients received $^{131}I$ therapy, the absorbed dose to the bone marrow is the limiting factor to the administered dose, and the duration of admission is deter-mined by the retained activity in the whole body. To monitor the whole body radioactivity, we used Eberline Smart 200 system using ionization chamber as a detector. With the time activity curve of the whole body, total body residence time was obtained. From the ICRP publication 53, the residence times of the source organs, such as kidney, urinary bladder content and stomach, were used to calculate the absorbed doses of the target organs, such as stomach, red marrow, bladder wall and remaineder total body. In 8 thyroid cancer patients with 175 mci of $^{131}I$ administered orally, the mean absorbed dose in the bladder wall was 375.1, in the stomach 285.1, red marrow 25.4 and total body 22.4 rad respectively. For the monitoring of the large administered activity, this method seemed to be quite useful.

• Journal of radiological science and technology
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• v.27 no.2
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• pp.35-43
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• 2004

Radioprotective effects of ginseng extracts on liver damage induced by high energy x-ray were studied. To one group of ICR male mice were given white(50 mg/kg/day for 7days, orally) and fermenta ginseng extracts(500 mg/kg/day for 7days, orally) before irrdiation. To another group were irradiated by 5 Gy dose of high energy x-ray. Contrast group were given with saline(0.1 ml). This study also investigated the radioprotective effect between SOD, CAT, hydrogen peroxide and ginseng extracts on hepatic damage. This study measured the level of superoxide dismutase(SOD), catalase(CAT), hydrogen peroxide($H_2O_2$) in liver tissue. Administrating orally white (50 mg/kg/day for 7days, orally) and fermenta ginseng extracts(500 mg/kg/day), the activity of SOD, CAT were generally increased and the hydrogen peroxide($H_2O_2$) was decreased. After irradiation, the activity of SOD, CAT were generally decreased and the hydrogen peroxide($H_2O_2$) was increased. Therefore, ginseng extracts increased antioxidative enzyme activity. And We know that the antioxidatant effect of extracts from white and fermenta ginseng protect radiation damage by direct antioxidant effect involving SOD, CAT. It was included that ginseng can protect against radiation damage through its antioxidatant properties.

• Radiation Oncology Journal
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• v.3 no.1
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• pp.29-33
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• 1985

흉선종은 비교적 드문 종양으로 알려져 있다. 예후를 알 수 있는 가장 중요한 인자는 수술시 육안적인 종양의 침윤정도이며, 치료는 수술에 의한 종양의 제거가 무엇보다 중요하고, 방사선 치료 역시 수출 후 국소적 계발의 방지를 위해 쓰이고 있다. 근치적 목적의 방사선 치료도 수술이 어려운 경우에 시행되고 있는 형편이다. 저자들은 1977년 1월부터 1984년 12월까지 세브란스병원 연세암센타 치료방사선과에서 흉선종 진단받고 치료한 14명의 환자를 후향성 분석에 의해 다음과 같은 결과를 얻었다. 1. 6명의 환자$(14\%)$가 근무력증을 나타냈다. 2. 주변조직의 침윤이 $86\%(12/14)$에서 관찰되었다. 3. $43\%$에서 육안적 완전 절제를 시행하였고 $14\%$에서 부분결제, 그리고 $43\%$에서는 생검만 시행 하였다. 4. 수술 후 혹은 근치적 목적의 방사선치료는 8명의 환자에서 시행하였으며 그중 현재 5명은 생존(4년, 2.8년, 1.6년, 1.4년, 1.3년), 3명은 사망(1년, 0.6년, 0.6년)하였다. 5. 방사선 치료선량은 대체료 $4,000\~4,500rad(1950\~7,000rad)$를 전후 흉곽 부위에 외부 조사하였다.