• 대한핵의학회:학술대회논문집
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• 대한핵의학회 1996년도 제35차 춘계학술대회 초록집
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• pp.185-185
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• 1996

• 핵의학기술
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• 제23권1호
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• pp.40-44
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• 2019

목적: $^{99m}Tc$-DTPA를 이용한 사구체 여과율 측정에서 신장(Height)과 체중(Weight)의 변동에 따른 사구체 여과율의 변화 정도를 확인하고 표준화된 신체 계측의 중요성에 대해 제고하고자 한다. 실험재료 및 방법: 서울아산병원 핵의학과에 사구체 여과율 검사를 위해 내원한 50명을 대상으로 전자의무기록(EMR)에 기록된 한 달 이내의 신체 계측 값의 변화를 조사하였고, 신장(Height)과 체중(Weight)의 변화 폭이 가장 컸던 값을 기준으로 신장(Height)과 체중(Weight)을 변화시키며 사구체 여과율을 재산출하여 그 변화를 분석하였다. 결과: 신장(Height)이 1cm 증가할 때마다 사구체 여과율은 평균 0.6%씩 감소하였고. 체중(Weight)이 1kg 증가할 때마다 사구체 여과율은 평균 1.6%씩 증가하였다. 결론: 신장(Height)과 체중(Weight)의 오류로 인한 사구체 여과율의 오류를 줄이기 위해서는 신체 계측 방법에 대한 표준화가 필요하며, 신체 계측에 영향을 줄 수 있는 변수에 대한 통제가 필요할 것으로 사료된다.

• Tribology and Lubricants
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• 제24권4호
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• pp.186-189
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• 2008

The flow induced vibration in the nuclear fuel assembly causes the fretting wear between the fuel cladding tubes and the supporting grids. The reduction in tube thickness due to the fretting wear could be related to the serious damage on nuclear fuel assembly. In this paper, the effect of the water flow on fretting wear of nuclear fuel cladding tube against supporting grid was investigated through the fretting wear tester with water spout equipment. The test results were compared with the data conducted in the stationary water. At stationary water environment the wear debris was trapped between fretting surfaces, and then the fretting wear occurred by three-body abrasion. However, in the case of water flow, the two-body abrasive wear was the dominant wear mechanism, because the wear debris was easily removed by water flow.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2259-2262
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• 2003

This paper describes visual tracking procedure of the underwater mobile robot for nuclear reactor vessel inspection, which is required to find the foreign objects such as loose parts. The yellowish underwater robot body tend to present a big contrast to boron solute cold water of nuclear reactor vessel, tinged with indigo by Cerenkov effect. In this paper, we have found and tracked the positions of underwater mobile robot using the two color informations, yellow and indigo. The center coordinates extraction procedures is as follows. The first step is to segment the underwater robot body to cold water with indigo background. From the RGB color components of the entire monitoring image taken with the color CCD camera, we have selected the red color component. In the selected red image, we extracted the positions of the underwater mobile robot using the following process sequences: binarization labelling, and centroid extraction techniques. In the experiment carried out at the Youngkwang unit 5 nuclear reactor vessel, we have tracked the center positions of the underwater robot submerged near the cold leg and the hot leg way, which is fathomed to 10m deep in depth.

• Mycobiology
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• 제39권2호
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• pp.79-84
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• 2011

Nuclear distribution within the extra-radical fungal structures and during spore production in the arbuscular mycorrhizae fungus Glomus intraradices was examined using an in vitro monoxenic culture system. A di-compartmental monoxenic culture system was modified using a nitrocellulose membrane and a coverglass slip for detailed observations. Nuclear distribution was observed using the fluorescent DNA binding probes SYBR Green I and DAPI. Both septate and non-septate mycelial regions were observed, but cytoplasmic contents were only found within non-septate mycelia. Nuclear fluorescent staining revealed that the non-septate hyphal region contained nuclei only with cytoplasm, and that nuclear distribution was limited by septa. Swollen hyphal bodies were often associated with septate and empty-looking hyphae. Cytoplasmic contents filled the swollen hyphal body from the non-septate hyphal region following removal of the septa. As a consequence, the swollen body developed into a new spore. These observations provide understanding about the distribution of AM fungal nuclei within extra-radical mycelia and during spore formation. The results suggest a mechanism by which the development of a cytoplasm-containing mycelium is controlled by the formation or removal of septa to efficiently maintain and proliferate essential contents. This mechanism may provide a survival strategy to the fungus.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.335-339
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• 2024

Employees of nuclear medicine facilities performing medical procedures with the use of open radioactive sources require continuous detailed control of exposure to ionizing radiation. Thermoluminescent (TL) detectors placed in dosimeters: for the whole body, for lenses, ring and wrist dosimeters were used to assess exposure. The highest whole-body exposure of (1.70 ± 1.09) µSv/GBq was recorded in nurses administering radiopharmaceutical to patients. The highest exposure to lenses and fingers was recorded for employees of the quality control zone and it was (8.08 ± 2.84) µSv/GBq and a maximum of (1261.46 ± 338.93) µSv/GBq, respectively. Workers in the production zone received the highest doses on their hands, i.e. (175.67 ± 13.25) µSv/GBq. The measurements performed showed that the analyzed workers may be classified as exposure category A. Wrist dosimeters are not recommended for use in isotope laboratories due to underestimation of ionizing radiation doses. Appropriately selected shields, which significantly reduce the dose received by employees, must be used in isotope laboratories. Periodic measurements confirmed that the appropriate optimization of exposure reduces the radiation doses received by employees.

• 핵의학기술
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• 제13권3호
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• pp.86-91
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• 2009

전신 영상 검사는 일반적인 핵의학 검사에 적용되고 있는 가장 기본적인 촬영 방법 중 하나이다. 이 때 각 검사마다 규정화된 테이블 이동 속도는 다양하다. 본 연구에서는 감마카메라의 사용 기간에 따른 노후 상태와 감마카메라 테이블 위의 무게 변화에 따른 테이블 이동 속도를 측정하여 그 정확성을 분석하는데 그 목적이 있다. 2008년 12월부터 2009년 2월까지 서울아산병원 핵의학과내에서 전신 영상 검사를 주로 시행하는 SIEMENS 장비 중 가장 사용기간이 긴 ECAM plus와 가장 최근에 설치된 SYMBIA T2를 대상으로 연구를 실시하였다. 각 장비별로 테이블 이동속도를 10, 15, 30 cm/min으로 나누어 매 10 cm씩 마다 총 100 cm의 구간을 타이머를 이용해 테이블 이동 시간을 측정하였다. 또한 표준 체중을 60~70 kg으로 감안하여 0, 66, 110 kg으로 나누어 체중에 따른 테이블의 이동 속도를 동일한 방법으로 측정하여 비교 분석하였다. 본 연구에서는 10 cm/min, 15 cm/min, 30 cm/min의 변동계수가 ECAM plus에서 1.23, 1.42, 2.02이었고, SYMBIA T2에서 1.23, 1.83, 2.28이었으며 테이블 이동속도가 증가될수록 변동은 많았다. 또한 무게 변화에 따른 각각의 변동계수는 0 kg에서 0.96, 1.45, 2.08이었고, 66 kg에서 1.32, 1.72, 2.27이며, 110 kg에서 1.37, 1.73, 2.14로 무게에 따른 큰 차이는 없었다. 95% 신뢰수준에서 통계적으로 유의한 차이는 있지 않아(p>0.05) 두 장비 모두 허용할 수 있는 범위안에 있었지만, ECAM plus에 비해 SYMBIA T2의 변동계수가 비교적 크게 측정되었다. 이러한 결과를 미루어 볼 때 Onco. Flash와 같은 Half-time 검사법을 실시하기 전에는 테이블의 이동과 테이블 이동 속도, 감마카메라의 상태를 점검하고, 좀 더 관심을 기울여야 하며 정기적인 점검을 일반화시키는 것이 유용할 것이라고 생각된다.

• Clinical and Experimental Reproductive Medicine
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• 제21권2호
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• pp.183-190
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• 1994

Purpose of the present study was to find the optimal culture conditions for the maturation and fertilization of immature oocytes by the use human body fluids and gonadotropins (Gn) in the mouse model. Cumulus-enclosed mouse immature oocytes were incubated in the medium containing various human body fluids with or without Gn in vitro, and examined to confirm nuclear maturation (NM) and fertilization. Female ICR mice were stimulated with 7.5 IU pregnant mares' serum gonadotropin (PMSG). Cumulus-enclosed immature oocytes were isolated at 48-52 hr post PMSG injection and cultured in TCM 199 supplemented with various concentrations (20, 50, and 70%) of human body fluids such as fetal cord serum (hCS), follicular fluid (hFF), peritoneal fluid (hPF) and amniotic fluid (hAF) in the presence or absence of 10 IU/ml PMSG and 10 IU/ml human chorionic gonadotropin (hCG) for 18 hr. Fetal calf serum (FCS) was used as a control for the supplements. Matured oocytes were fertilized with sperm collected from the epididymis of male mice. Fertilization was conducted in T6 medium containing 15 mgl ml bovine serum albumin, and confirmed at 6 hr post-insemination. Evaluation of nucler maturation and fertilization was carried out by rapid staining using fuchin. There was no significant difference between the effects of human body fluids and FCS supplements on nuclear maturation of cumulus enclosed mouse immature oocytes. When maturation medium was supplemented with 20% hPF or 20% hAF, fertilization rates were significantly (P<0.01) lower than that of 20% FCS, hCS and hFF groups. However, higher concentrations of body fluids during IVM were not more beneficial on fertilizability of oocytes. The addition of Gn significantly increased the fertilization rates in hPF and hAF groups (hPF without Gn; 51.5%, compared with 85.1% for addition of Gn, and hAF without Gn; 30.1% compared with 85.8% for addition of Gn) at 20% concentration. These results suggest that human body fluids at 20% concentration and gonadotropins can be used as supplements for the maturation of mouse immature oocytes in vitro. When gonadotropins supplemented with the human body fluids in the maturation medium, fertilizability of mouse immature oocytes was increased in hPF and hAF groups. These results can be applied to maturation of human immature oocytes in vitro.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.2960-2967
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• 2021

In this work, a new hardening model is proposed for the depth-dependent hardness of ion-irradiated polycrystals with obvious grain size effect. Dominant hardening mechanisms are addressed in the model, including the contribution of dislocations, irradiation-induced defects and grain boundaries. Two versions of the hardening model are compared, including the linear and square superposition models. A succinct parameter calibration method is modified to parametrize the models based on experimentally obtained hardness vs. indentation depth curves. It is noticed that both models can well characterize the experimental data of unirradiated polycrystals; whereas, the square superposition model performs better for ion-irradiated materials, therefore, the square superposition model is recommended. In addition, the new model separates the grain size effect from the dislocation hardening contribution, which makes the physical meaning of fitted parameters more rational when compared with existing hardness analysis models.

• 한국가축번식학회지
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• 제24권2호
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• pp.217-222
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• 2000

본 연구는 세포의 휴면처리가 소 태아섬유아세포 유래 핵이식란의 핵형변화와 체외발육에 미치는 영향을 검토하였다. 임신 3∼4 개월령 한우 웅성 태아의 피부세포를 채취하여 계대배양 후 동결하였다가 핵이식 전에 혈청기아처리 또는 confluency방법으로 휴면처리를 하여 미수정란의 탈핵세포질에 이식하였다. 전기융합과 활성화처리 후 7∼9 일간 체외배양하여 발육능을 검토하였으며, 일부는 whole-mount 법으로 고정하여 염색질 구조를 관찰하였다. 복제란의 극체방출율은 혈청기아처리구와 confluence 구에서 각각 24.5% 와 20.3% 로 무처리구(36.0%) 에 비해 낮은 경향을 보였다. 활성화 후 1개의 염색질괴를 갖는 복제란은 혈청기아처리구(50.9%)와 confluence구 (49.2%)가 무처리구 (40.0%) 보다 높은 경향을 보였다. 극체방출에 따른 염색질의 구조는 극체 미방출구에서 정상적인 1개의 염색질괴를 갖는 핵이식란이 60.5% 로, 극체 방출구 (4.7%) 에 비하여 유의적으로 높았다 (P＜0.01). 배반포기 발육율은 혈청기아처리구 (21.7%) 와 confluence (20.9%) 가 무처리구 (14.1%) 에 비하여 비교적 높게 나타났다. 본 연구의 결과 혈청기아처리나 confluency 방법에 의한 donor 세포의 휴면처리는 태아섬유아세포 유래 핵이식란의 비정상적인 핵형변화를 감소시켜 체외발육능을 향상시키는 것으로 사료된다.