• Title/Summary/Keyword: HuC

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Evaluation of Skin Dose and Image Quality on Cone Beam Computed Tomography (콘빔CT 촬영 시 mAs의 변화에 따른 피부선량과 영상 품질에 관한 평가)

  • Ahn, Jong-Ho;Hong, Chae-Seon;Kim, Jin-Man;Jang, Jun-Young
    • The Journal of Korean Society for Radiation Therapy
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    • v.20 no.1
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    • pp.17-23
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    • 2008

  • Purpose: Cone-beam CT using linear accelerator attached to on-board imager is a image guided therapy equipment. Because it is to check the patient's set-up error, correction, organ and target movement. but imaging dose should be cause of the secondary cancer when taking a image. The aim of this study is investigation of appropriate cone beam CT scan mode to compare and estimate the image quality and skin dose. Materials and Methods: Measurement by Thermoluminescence dosimeter (TLD-100, Harshaw) with using the Rando phantom are placed on each eight sites in seperately H&N, thoracic, abdominal section. each 4 methods of scan modes of are measured the for skin dose in three time. Subsequently, obtained average value. Following image quality QA protocol of equipment manufacturers using the catphan 504 phantom, image quality of each scan mode is compared and analyzed. Results: The results of the measured skin dose are described in here. The skin dose of Head & Neck are measured mode A: 8.96 cGy, mode B: 4.59 cGy, mode C: 3.46 cGy mode D: 1.76 cGy and thoracic mode A: 9.42 cGy, mode B: 4.58 cGy, mode C: 3.65 cGy, mode D: 1.85 cGy, and abdominal mode A: 9.97 cGy, mode B: 5.12 cGy, mode C: 4.03 cGy, mode D: 2.21 cGy. Approximately, dose of mode B are reduced 50%, mode C are reduced 60%, mode D are reduced 80% a point of reference dose of mode A. the results of analyzed HU reproducibility, low contrast resolution, spatial resolution (high contrast resolution), HU uniformity in evaluation item of image quality are within the tolerance value by recommended equipment manufacturer in all scan mode. Conclusion: Maintaining the image quality as well as reducing the image dose are very important in cone beam CT. In the result of this study, we are considered when to take mode A when interested in soft tissue. And we are considered to take mode D when interested in bone scan and we are considered to take mode B, C when standard scan. Increasing secondary cancer risk due to cone beam CT scan should be reduced by low mAs technique.

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Knock-down of human MutY homolog (hMYH) decreases phosphorylation of checkpoint kinase 1 (Chk1) induced by hydroxyurea and UV treatment

  • Hahm, Soo-Hyun;Park, Jong-Hwa;Ko, Sung-Il;Lee, You-Ri;Chung, In-Sik;Chung, Ji-Hyung;Kang, Lin-Woo;Han, Ye-Sun
    • BMB Reports
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    • v.44 no.5
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    • pp.352-357
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    • 2011

  • The effect of human MutY homolog (hMYH) on the activation of checkpoint proteins in response to hydroxyurea (HU) and ultraviolet (UV) treatment was investigated in hMYH-disrupted HEK293 cells. hMYH-disrupted cells decreased the phosphorylation of Chk1 upon HU or UV treatment and increased the phosphorylation of Cdk2 and the amount of Cdc25A, but not Cdc25C. In siMYH-transfected cells, the increased rate of phosphorylated Chk1 upon HU or UV treatment was lower than that in siGFP-transfected cells, meaning that hMYH was involved in the activation mechanism of Chk1 upon DNA damage. The phosphorylation of ataxia telangiectasia and Rad3-related protein (ATR) upon HU or UV treatment was decreased in hMYH-disrupted HEK293 and HaCaT cells. Co-immunoprecipitation experiments showed that hMYH was immunoprecipitated by anti-ATR. These results suggest that hMYH may interact with ATR and function as a mediator of Chk1 phosphorylation in response to DNA damage.

  • https://doi.org/10.5483/BMBRep.2011.44.5.352 인용 PDF KSCI

Effect of Muscle Activation Change of Lower Limb According to Whole Body Vibration During Different Squat Exercises (다양한 스쿼트 자세 수행 시 전신진동자극이 하지 근 활성도에 미치는 영향)

  • Seo, S.B.;Kang, S.R.;Yu, C.H.;Min, J.Y.;Kwon, T.K.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.8 no.1
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    • pp.33-40
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    • 2014

  • The objective of this study was to assess leg muscle activities during whole body vibration (WBV) training with various squat position exercises. Subjects performed four different squat exercises on a vibration platform (VM-10, Sonicworld Co.) Ten healthy women volunteers (age $21{\pm}1.3years$, height $160{\pm}2.1cm$, weight $52{\pm}4.6kg$) were selected. EMG signals four leg muscles were taken and analyzed. The exercises were performed both with 10 seconds WBV and without 10 seconds WBV. Muscle activities during WBV were compared with non-vibration stimulus. In the result, EMG signals caused by WBV were significantly higher (P<0.05) compared with non-vibration stimulus in all leg muscles and squat exercises. The increase in muscle activity caused by Whole body vibration was significantly higher (P<0.05) in LS and OS compared with HU&HS.

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