• Title/Summary/Keyword: radiation response

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Influence of viscous effects on numerical prediction of motions of SWATH vessels in waves

  • Brizzolara, Stefano;Bonfiglio, Luca;Medeiros, Joao Seixas De
    • Ocean Systems Engineering
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    • v.3 no.3
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    • pp.219-236
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    • 2013
  • The accurate prediction of motion in waves of a marine vehicle is essential to assess the maximum sea state vs. operational requirements. This is particularly true for small crafts, such as Autonomous Surface Vessels (ASV). Two different numerical methods to predict motions of a SWATH-ASV are considered: an inviscid strip theory initially developed at MIT for catamarans and then adapted for SWATHs and new a hybrid strip theory, based on the numerical solution of the radiation forces by an unsteady viscous, non-linear free surface flow solver. Motion predictions obtained by the viscous flow method are critically discussed against those obtained by potential flow strip theory. Effects of viscosity are analyzed by comparison of sectional added mass and damping calculated at different frequencies and for different sections, RAOs and motions response in irregular waves at zero speed. Some relevant conclusions can be drawn from this study: influence of viscosity is definitely non negligible for SWATH vessels like the one presented: amplitude of the pitch and heave motions predicted at the resonance frequency differ of 20% respectively and 50%; in this respect, the hybrid method with fully non-linear, viscous free surface calculation of the radiation forces turns out to be a very valuable tool to improve the accuracy of traditional strip theories, without the burden of long computational times requested by fully viscous time domain three dimensional simulations.

Pulmonary Artery Sarcoma - One Case Report - (폐동맥에서 발생한 육종 - 1례보고 -)

  • Kim, Hyeong-Ryul;Kim, Kyung-Hwan;Ahn, Hyuk
    • Journal of Chest Surgery
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    • v.35 no.9
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    • pp.692-696
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    • 2002
  • Pulmonary artery sarcoma is a rare disease and hard to diagnose; therefore, suspicion is very important for the diagnosis and treatment. Surgical resection is almost always needed because of progressive right heart failure. Adjuvant chemotherapy and radiation therapy are still controversial. We report a case of a 42-year-old man who had a right pulmonary arterial tumor Curative resection was impossible because the tumor invaded the left pulmonary artery. Palliative endarterectomy was performed followed by radiation therapy. The patient refused the chemotherapy. Until the postoperative 6th month, the residual tumor was stable. However, 15 months later, follow-up chest computed tomography revealed a metastatic pulmonary nodule at left lower lobe and the increased residual tumor. The patient received chemotherapy with limited tumor response. The metastatic nodule and residual tumor did not increase but bone scan revealed a rib metastasis at postoperative 24 months. He will be receiving additional chemotherapy.

Effects of Salicylic Acid on Oxidative Stress and UV-B Tolerance in Cucumber Leaves (살리실산이 오이 잎의 산화적 스트레스와 UV-B 내성에 미치는 영향)

  • Hong, Jung-Hee;Kim, Tae-Yun
    • Journal of Environmental Science International
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    • v.16 no.12
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    • pp.1345-1353
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    • 2007
  • The effect of salicylic acid(SA) on antioxidant system and protective mechanisms against UV-B induced oxidative stress was investigated in cucumber(Cucumis sativus L.) leaves. UV-B radiation and SA were applied separately or in combination to first leaves of cucumber seedlings, and dry matter accumulation, lipid peroxidation and activities of antioxidant enzymes were measured in both dose and time-dependant manner. UV-B exposure showed reduced levels of fresh weight and dry matter production, whereas SA treatment significantly increased them. SA noticeably recovered the UV-B induced inhibition of biomass production. UV-B stress also affected lipid peroxidation and antioxidant enzyme defense system. Malondialdehyde(MDA), a product of lipid peroxidation, was greatly increased under UV-B stress, showing a significant enhancement of a secondary metabolites, which may have antioxidative properties in cucumber leaves exposed to UV-B radiation. Combined application of UV-B and SA caused a moderate increase in lipid peroxidation. These results suggest that SA may mediate protection against oxidative stress. UV-B exposure significantly increased SOD, APX, and GR activity compared with untreated control plants. Those plants treated with 1.0 mM SA showed a similar pattern of changes in activities of antioxidant enzymes. SA-mediated induction of antioxidant enzyme activity may involve a protective accumulation of $H_2O_2$ against UV-B stress. Moreover, their activities were stimulated with a greater increase by UV-B+SA treatment. The UV-B+SA plants always presented higher values than UV-B and SA plants, considering the adverse effects of UV-B on the antioxidant cell system. ABA and JA, second messengers in signaling in response to stresses, showed similar mode of action in UV-B stress, supporting that they may be important in acquired stress tolerance. Based on these results, it can be suggested that SA may participates in the induction of protective mechanisms involved in tolerance to UV-B induced oxidative stress.

Effects of Hexaconazole on Growth and Antioxidant Potential of Cucumber Seedlings under UV-B Radiation

  • Kim, Tae-Yun;Hong, Jung-Hee
    • Journal of Environmental Science International
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    • v.21 no.12
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    • pp.1435-1447
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    • 2012
  • The present study was conducted to determine the effect of hexaconazole (HEX), a triazole fungicide, on the growth, yield, photosynthetic response and antioxidant potential in cucumber (Cucumis sativus L.) plants subjected to UV-B stress. UV-B radiation and HEX were applied separately or in combination to cucumber seedlings. The growth parameters were significantly reduced under UV-B treatment, however, this growth inhibition was less in HEX treated plants. HEX caused noticeable changes in plant morphology such as reduced shoot length and leaf area, and increased leaf thickness. HEX was quite persistent in inhibiting shoot growth by causing a reduction in shoot fresh and dry weight. HEX noticeably recovered the UV-B induced inhibition of biomass production. Significant accumutation in anthocyanin and flavonoid pigments in the leaves occurred as a result of HEX or UV-B treatments. HEX permitted the survival of more green leaf tissue preventing chlorophyll content reduction and higher quantum yield for photosystemII under UV-B exposure. HEX treatment induced a transient rise in ABA levels in the leaves, and combined application of HEX and UV-B showed a significant enhancement of ABA content which activates $H_2O_2$ generation. UV-B exposure induced accumulation of $H_2O_2$ in the leaves, while HEX prevented UV-B induced increase in $H_2O_2$, indicating that HEX serves as an antioxidant agent able to scavenge $H_2O$ to protect cells from oxidative damage. An increase in the ascorbic acid was observed in the HEX treated cucumber leaves affecting many enzyme activities by removing $H_2O_2$ during photosynthetic processes. The activities of antioxidant enzymes including catalase(CAT), ascorbate peroxidase(APX), superoxide dismutase(SOD) and peroxidase(POD) in the leaves in the presence of HEX under UV-B stress were higher than those under UV-B stress alone. These findings suggest that HEX may participate in the enhanced tolerance to oxidative stress. From these results it can be concluded that HEX moderately ameliolate the effect of UV-B stress in cucumber by improving the components of antioxidant defense system.

Neutron Personal Dose Equivalent Evaluation Using Panasonic UD-809P Type TLD Albedo Dosimeters (Panasonic UD-809P 알비도 열형광선량계를 이용한 중성자 개인선량당량 평가)

  • Shin, Sang-Woon;Son, Joong-Kwon;Jin, Hua
    • Journal of Radiation Protection and Research
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    • v.24 no.3
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    • pp.143-154
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    • 1999
  • Panasonic UD-809P type albedo neutron TL dosimeters mounted on a water phantom were used to measure neutron personal dose equivalent in a Korean nuclear power plant. From the measured TL readings, personal dose equivalents from thermal, epithermal and fast neutrons were evaluated by using a method adopted in a neutron dose calculation algorithm for Panasonic UD-809P type albedo neutron TL dosimeters, which was suggested in a Panasonic TLD System User's Manual. The results showed that personal dose equivalent from fast neutrons could not be adequately evaluated in a field with high thermal neutron fraction to be encountered in a nuclear power plant. This seems to be related to the incomplete incidence of albedo thermal neutrons to the TL dosimeters. In order to evaluate appropriately the personal dose equivalent from fast neutrons in the field condition, new method fer the neutron dose calculation algorithm was suggested. In this new method, neutrons are grouped into thermal neutrons and fast neutrons. For each neutron component, equations for TL response, sensitivity factor, calibration factor and personal dose equivalent were derived.

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Uni-Planar Elliptical UWB Antenna with Band-Notched Characteristic and Modified Ground Plane (변형된 접지면과 대역 저지 특성을 갖는 단일 평면 타원형 UWB 안테나)

  • Park Gil-Young;Shin Ho-Sub;Oh Byoung-Cheol;Kim Nam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.12 s.103
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    • pp.1194-1205
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    • 2005
  • This paper proposes a uni-planar elliptical element UWB antenna with band-notched characteristic and modified pound plane fed by CPW. The antenna achieves VSWR below 2 for UWB band(3.1 GHz${\~}$10.6 GHz). In addition, a band-notched characteristic is achieved by inserting a horizontal slot on the radiation element to avoid the interference with 5 GHz(5.15 GHz${\~}$5.825 GHz) band limited by IEEE 802.1la. The antenna has a thin profile, compact size, and ease of manufacture by adopting a CPW feed structure without any additional background plane. Measured data show that the proposed antenna has good return loss below -10 dB, about 2.1 dB${\~}$4.75 dB maximum gain over the bandwidth, omni-directional radiation patterns, linear phase response.

Effects of whole-body gamma-irradiation on the peripheral blood of ICR mouse (ICR 마우스에서 방사선 조사 용량에 따른 혈액변화의 관찰)

  • Kim, Sung-Ho;Lee, Jong-Hwan;Kim, Se-Ra;Lee, Hae-June;Lee, Yun-Sil;Kim, Tae-Hwan;Ryu, Si-Yun;Jo, Sung-Kee;An, Mi-Yeong
    • Korean Journal of Veterinary Research
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    • v.42 no.2
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    • pp.183-190
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    • 2002
  • The effects of ionizing radiation on the peripheral blood elements of ICR mouse were examined after varying doses of whole-body gamma-irradiation. ICR mice (n=50) were exposed to 0, 2, 4, 6 and 8 Gy gamma-ray ($^{60}Co$) at 10 Gy/min. The animals were studied for their hematological response on days, 3, 7, 14, 21, 42 and 56 post irradiation. No significant change was noted in erythrocyte, hemoglobin and hematocrit values after irradiation with dose of 2 Gy. Decreasing erythrocyte, hemglobin and hematocrit values occured after irradiation with doses of more than 4 Gy on day 7 after irradiation followed by a sharp fall on day 14. A recovery in these values was noted after 3 weeks of irradiation. Thrombocyte counts decreased on day 3, reaching minimal values on day 7. The total number of leukocytes was reduced on day 3, mainly because of a decrease in the lymphocyte population. An evident lymphopenia and neutropenia occur almost on the day 3 and last up to the day 28 after irradiation. All of the hematological values decreased in the blood in a dose-dependent manner at the same time.

Clinical Observation of Whole Brain Radiotherapy Concomitant with Targeted Therapy for Brain Metastasis in Non-small Cell Lung Cancer Patients with Chemotherapy Failure

  • Cai, Yong;Wang, Ji-Ying;Liu, Hui
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5699-5703
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    • 2013
  • Objective: To investigate the clinical effects of whole brain radiotherapy concomitant with targeted therapy for brain metastasis in non-small cell lung cancer (NSCLC) patients with chemotherapy failure. Materials and Methods: Of the 157 NSCLC patients with chemotherapy failure followed by brain metastasis admitted in our hospital from January 2009 to August 2012, the combination group (65 cases) were treated with EGFR-TKI combined with whole brain radiotherapy while the radiotherapy group (92 cases) were given whole brain radiotherapy only. Short-term effects were evaluated based on the increased MRI in brain 1 month after whole brain radiotherapy. Intracranial hypertension responses, hematological toxicity reactions and clinical effects of both groups were observed. Results: There were more adverse reactions in the combination group than in radiotherapy group, but no significant differences were observed between the two groups in response rate (RR) and disease control rate (DCR) (P>0.05). Medium progression free survival (PFS), medium overall survival (OS) and 1-year survival rate in combination group were 6.0 months, 10.6 months and 42.3%, while in the radiotherapy group they were 3.4 months, 7.7 months and 28.0%, respectively, which indicated that there were significant differences in PFS and OS between the two groups (P<0.05). Additionally, RPA grading of each factor in the combination group was a risk factor closely related with survival, with medium PFS in EGFR and KRAS mutation patients being 8.2 months and 11.2 months, and OS being 3.6 months and 6.3 months, respectively. Conclusions: Whole brain radiotherapy concomitant with target therapy is favorable for adverse reaction tolerance and clinical effects, being superior in treating brain metastasis in NSCLC patients with chemotherapy failure and thus deserves to be widely applied in the clinic.

A Questionnaire Design Strategy for Enhancing the Rationality and Testing for the Validity of Choice Experiments Using Example Choice Questions (Choice Experiments의 합리성 제고 및 타당성 검증을 위한 설문지 디자인 연구 - 예제 도입 방안을 중심으로 -)

  • Kim, Yong-Joo
    • Environmental and Resource Economics Review
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    • v.14 no.1
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    • pp.1-24
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    • 2005
  • One of the most important factors that determine the quality of a stated preference study is questionnaire design. This study introduces strategies for enhancing the rationality and testing for the validity of choice experiments(CE) using "example" choice questions that mimic the main choice questions. From the case study of WTP for reduced radon radiation exposures in the home, the study found that screening out irrational responses, 12% of the effective responses, resulted in a meaningful increase in model fit. Meanwhile the study tested for anchoring effects, as a way of confirming the divergent validity of the study, by looking at equality of models estimated for two subsamples. The overall test results were mixed. The pros and cons of the questionnaire design strategy employed are also reported.

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Emergency Environmental Monitoring for the Decision-Aiding on Public Protective Actions during a Nuclear Accident (원자력 사고시 주민 보호조치 결정 지원을 위한 비상 환경감시)

  • Choi, Yong-Ho;Choi, Geun-Sik;Han, Moon-Hee;Lee, Han-Soo;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
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    • v.30 no.3
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    • pp.131-148
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    • 2005
  • In a nuclear emergency, protective actions for the public should be taken in time. It is internationally proposed that generic intervention levels (GILs) and generic action levels, determined based on cost-benefit analyses, be used as the decision criteria for protective actions. Operational intervention levels (OILs) are directly or easily measurable quantities corresponding to these generic levels. To assess the necessity of protective actions in a nuclear emergency, it is important that the environmental monitoring data required for applying and revising OILs should be promptly produced. It is discussed what and how to do for this task in the course of the emergency response. For an emergency environmental monitoring to be performed effectively, a thorough preparedness has to be made including maintenance of the organization and equipments, establishment of various procedure manuals, development of a supporting computer system and periodical training and exercises. It is pointed out that Korean legal provisions concerning GILs and OILs need to be amended or newly established.