• 제목/요약/키워드: Dose loss

검색결과 581건 처리시간 0.03초

Changes of Hemodynamics and Renal Function due to Acute Cadmium Exposure in Rats

  • Kim, Jae-Joong;Kim, Yung-Kyu
    • The Korean Journal of Physiology and Pharmacology
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    • 제10권3호
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    • pp.137-141
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    • 2006
  • The systolic and diastolic pressures in anesthetized Sprague-Dawley male rats were greatly decreased after single-dose of Cd treatment without significant changes in heart rate. There was a fluid-shift into the third space and/or -loss through the kidney, since plasma $Na^+$ concentration and hematocrit ratio were significantly increased by acute Cd exposure. The present study showed that the sustained hypotensive effect of single-dose Cd on the cardiovascular system might have resulted from the systemic hypovolemia. Furthermore, renal excretion of electrolytes, including $Na^+$ and $K^+$, and urine flow rate were increased by Cd intoxication. Interestingly, the ratio of $Na^+/K^+$ excretion was increased and reached the maximum level 3 hours after Cd injection and returned to the normal level after 7 hours. Nevertheless, there was no difference in the regression analysis of $Na^+$ excretion and urine flow rate in both groups. Therefore, the increase in the urine volume seemed to enhance the excretion of $Na^+$. This study strongly suggest that the hypotensive effect of Cd is mediated by systemic $Na^+$ loss through the kidney and/or hypovolemia via fluid-shift.

광섬유 브래그 격자 센서를 이용한 단일모드 광섬유의 방사선 영향 분석 (The Analysis of Radiation Effects of Single-Mode Optical Fibers Using Fiber Bragg Grating Sensors)

  • 김종열;이남호;정현규;김영웅;한원택
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2013년도 춘계학술대회
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    • pp.732-735
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    • 2013
  • 본 논문에서는 광섬유 브래그 격자 센서를 이용하여 4종류의 단일모드 광섬유에 대한 감마선 조사에 따른 전송손실을 측정하였다. 시험에 사용된 방사선원은 $Co^{60}$ 감마선원으로, 총 2시간동안 0.6 kGy/hr, 1.2 kGy/hr, 2.4 kGy/hr의 선량률로 감마선을 조사하였다. 실험을 통하여 광섬유 종류에 따른 선량률 효과를 확인하였고, 방사선 유입손실 변화를 통한 방사선 민감도를 평가하였다.

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계육의 위생화 및 안전 저장을 위한 감마선 조사 (Sanitizing and Extending of Shelf Life of Chicken Meat by Gamma Irradiation)

  • 이주운;이경행;육홍선;이현자;변명우
    • 한국식품위생안전성학회지
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    • 제14권2호
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    • pp.160-166
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    • 1999
  • Microbial populations of total aerobic bacteria and coliforming bacteria, TBA, Hunter's color value, heme pigments, muscle protein solubility, cooking loss and shear force were investigated fro evaluating the shelf life of chicken legs gamma-irradiated at doses of 1, 3, 5 and 10 kGy with air-contained and vacuum-packaged methods. The initial microbial populations decreased with gamma irradiation depending upon the dose, and microorganisms in the vacuum-packaged samples were inhibited more than those in the air-contained samples. Hunter's L and a values of the surface and inside of the legs increased by gamma irradiation, showing a bright red color and the red color was maintained during the storage of both samples. The concentrations of oxymyoglobin among the heme pigments increased by gamma irradiation. Muscle protein solubility slightly increased by increasing the applied dose. There were no significant differences in the cooking loss and shear force values. In conclusion, the combination of gamma irradiation and vacuum-packaging could extend the shelf life of chilled chicken without deterioration of the quality.

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변압기유의 유전특성에 미치는 고조사 전자선의 영향 (The Effect on the Dielectric Characteristics of Transformer Oils due to the High Dose Electron Beam)

  • 조경순;김이두;김석환;김왕곤;소병문;홍진웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 C
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    • pp.1417-1419
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    • 1997
  • In this paper, the dielectric properties is made researches by the dose of electron beam in order to investigate the electrical properties for transformer oils due to electron beam irradiation. To measure the dielectric loss of irradiated specimen, the liquid electrode of coaxial cylindrical shape is used, and its geometric capacitance is 16 [pF]. And the dielectric dissipation factor, $tan{\delta}$, is measured by using the Video Bridge 2150. The thermal static oven with an automatic temperature controller is used so as to apply specific temperature to specimen. This experiments for measuring the dielectric loss is performed at $20{\sim}120[^{\circ}C]$ in temperature range, $30{\sim}1.5{\times}10^5[Hz]$ in frequency and $300{\sim}500[mV]$ in voltage.

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Parasite Infiltration and Apoptosis in Spleen upon Toxoplasma gondii Infection

  • Lee, Su-Hwa;Chu, Ki-Back;Quan, Fu-Shi
    • Parasites, Hosts and Diseases
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    • 제57권5호
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    • pp.537-541
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    • 2019
  • Toxoplasma gondii infection induces parasite infiltration and apoptosis in the spleen. However, dose-dependent parasite infiltration, apoptosis, body weight alternations and survival in mice remain largely unknown. In this study, mice were intraperitoneally infected with 10, 30 or 100 tachyzoites of T. gondii, respectively. Parasite infiltration and apoptosis in the spleen were analyzed on days 3, 7, and 9 post-infection by immunohistochemistry and flow cytometry. Significantly higher levels of T. gondii infiltration and apoptosis in the spleen were found in 30 and 100 tachyzoites infected mice compared to 10 tachyzoites infected mice on days 7 and 9 post-infection. Although 30 and 100 tachyzoites infected mice showed significant body weight loss compared to 10 tachyzoites infected mice, all of the 100, 30, and 10 tachyzoites infected mice died by days 12, 15, and 17, each respectively. Interestingly, T. gondii infiltration in 10 tachyzoites infected mice were limited to capsule area of the spleen on day 9 post-infection. Several areas of parasite infiltrations were found in the 30 tachyzoites infected mice, where noticeable levels of splenic capsule de-adhesion occurred. These results indicated that parasite infiltration and apoptosis in the spleen, as well as body weight loss (survival) are closely correlated with infection dosage. The level of T. gondii infiltration and apoptosis in the spleen and splenic de-adhesion were dependent on the parasite dose.

KEY IMPACT PARAMETERS FOR APPLICATION OF ALTERNATIVE SOURCE TERM TO KORI UNIT 1

  • Lee, Seung-Chan
    • Nuclear Engineering and Technology
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    • 제42권4호
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    • pp.394-413
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    • 2010
  • The object of this paper is to identify the key elements that impact a radiation dose at EAB (Exclusion Area Boundary). This study is based on the AST (Alternative Source Terms) as defined in Regulatory Guide 1.183. The LOCA (Loss of Coolant Accident) and the LRA (Locked Rotor Accident) are selected as limiting cases. A sensitivity analysis of accidental behavior with respect to various parameters during LOCA and LRA at Kori Unit 1 is also undertaken for the following objectives: to determine the limiting parameters, to find the impact trend of the radiation dose, and to find the safety margin between AST and TID (Technical Information Document) methodologies. This work confirms that key parameters are particulate removal rate, decontamination factor, iodine chemical form, gap fraction, partitioning factor, and the impact of isotopes group. Comparing TID with AST, the radiation dose of TID is about 80% greater than that of AST under a LOCA, and about 60% greater than that of AST for the case of a LRA; thus the safety margin is remarkably increased when the AST is used. In this work, the sensitivity analysis results are presented in terms of a sensitivity index called the "NDD (Normalized Dose Difference)", which compares the impact of parameters with that of a reference case. These values are derived by using a combination of the leak rate (primary to secondary), iodine chemical form, gap fraction, partitioning factor, spray removal rate, source term, and other variables.

Identification of an effective and safe bolus dose and lockout time for patient-controlled sedation (PCS) using dexmedetomidine in dental treatments: a randomized clinical trial

  • Seung-Hyun Rhee;Young-Seok Kweon;Dong-Ok Won;Seong-Whan Lee;Kwang-Suk Seo
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제24권1호
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    • pp.19-35
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    • 2024
  • Background: This study investigated a safe and effective bolus dose and lockout time for patient-controlled sedation (PCS) with dexmedetomidine for dental treatments. The depth of sedation, vital signs, and patient satisfaction were investigated to demonstrate safety. Methods: Thirty patients requiring dental scaling were enrolled and randomly divided into three groups based on bolus doses and lockout times: group 1 (low dose group, bolus dose 0.05 ㎍/kg, 1-minute lockout time), group 2 (middle dose group, 0.1 ㎍/kg, 1-minute), and group 3 (high dose group, 0.2 ㎍/kg, 3-minute) (n = 10 each). ECG, pulse, oxygen saturation, blood pressure, end-tidal CO2, respiratory rate, and bispectral index scores (BIS) were measured and recorded. The study was conducted in two stages: the first involved sedation without dental treatment and the second included sedation with dental scaling. Patients were instructed to press the drug demand button every 10 s, and the process of falling asleep and waking up was repeated 1-5 times. In the second stage, during dental scaling, patients were instructed to press the drug demand button. Loss of responsiveness (LOR) was defined as failure to respond to auditory stimuli six times, determining sleep onset. Patient and dentist satisfaction were assessed before and after experimentation. Results: Thirty patients (22 males) participated in the study. Scaling was performed in 29 patients after excluding one who experienced dizziness during the first stage. The average number of drug administrations until first LOR was significantly lower in group 3 (2.8 times) than groups 1 and 2 (8.0 and 6.5 times, respectively). The time taken to reach the LOR showed no difference between groups. During the second stage, the average time required to reach the LOR during scaling was 583.4 seconds. The effect site concentrations (Ce) was significantly lower in group 1 than groups 2 and 3. In the participant survey on PCS, 8/10 in group 3 reported partial memory loss, whereas 17/20 in groups 1 and 2 recalled the procedure fully or partially. Conclusion: PCS with dexmedetomidine can provide a rapid onset of sedation, safe vital sign management, and minimal side effects, thus facilitating smooth dental sedation.

가시오가피 추출물의 독성경감 및 면역증강효과 (Effects of Protein-Bound Polysacharide Isolated from Acanthopananx senticosus in Reducing the Toxic Effects of Cisplatin)

  • 이경호;윤원호
    • 생약학회지
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    • 제38권2호통권149호
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    • pp.152-156
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    • 2007
  • Protein-bound polysaccharide is derived from Acanthopananx senticosus by the cold water extraction. The aim of the study was to evaluate the effects of PS against weight loss and hematological change as a indication of toxicity produced by the treatment of cisplatin. PS protected the weight loss caused by cisplatin (6 mg/kg) and significantly recovered hematological change. Treatment of PS showed the recovery on the weight loss and hematological change as indicators of toxicity of cisplatin treatment. By increasing lymphocyte proliferation and cytokine production, PS may be highly effective in protecting against cisplatin-induced toxicity. The results suggest PS might have a role in reducing toxicity or permitting larger dose of cisplatin to be given.

Effect of Helminthiasis on Zinc Metabolism

  • Musalia, L.M.;Aggett, P.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권2호
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    • pp.276-279
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    • 2001
  • The effect of helminthiasis on zinc metabolism was monitored using endogenous $^{65}Zn$ after intraperitoneal injection of 1 g of $^{65}Zn$ as zinc chloride. In the first experiment zinc turnover was investigated in 18 male weanling rats, which were randomly divided into 3 groups. One group was infected with 73 third stage larvae of Nippostrongylus brasiliensis per gram body weight ; the other groups were the pair-fed and ad lib-fed controls. The route of loss of zinc was investigated in the second experiment with the same design using 18 animals with a lower dose of infection (33 larvae per gram body weight). The biological half life of endogenous $^{65}Zn$ was lower (p<0.05) in the infected group as compared to the controls. In the later phase of infection (9th to 16th day) there was reduced retention of $^{65}Zn$ and increased loss (p<0.05) of $^{65}Zn$ from the body though urine and faeces. It was concluded that infection of N. brasiliensis was accompanied by increased loss of endogenous Zn through faeces and urine.

영상 정보 손실을 최소화하는 방사선 차폐체 연구 (Radiation Shielding to Minimize Image Information Loss)

  • 장수한;박상현;주명식
    • 한국방사선학회논문지
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    • 제17권3호
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    • pp.449-457
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    • 2023
  • 방사선 감수성이 높은 부위의 방사선 검사 시 피폭선량 감소를 위해 사용하는 차폐체가 조사야에 포함될 경우 방사선 영상에서 밝게 표현되며 영상 정보의 손실이 발생한다. 영상 정보의 손실은 진단과 치료에 제한점을 주며 재촬영이 필요할 경우, 불필요한 방사선에 노출될 수 있다. 본 논문에서는 수용성 요오드 조영제와 물을 혼합한 다양한 농도의 차폐체를 제작하여 영상 손실을 최소화하면서 기존 차폐체와 동등한 차폐 효과를 발생하는 방사성 방호 차폐체를 연구하고자 하였다. 차폐체는 물 100 ml, 수용성 요오드 조영제 100 ml, 수용성 요오드 조영제와 물을 20 : 80, 40 : 60, 60 : 40, 80 : 20 비율로 각각 100 ml를 제작했다. 차폐 효율을 측정하기 위해서 차폐체를 가로 9.5 cm, 세로 9.5cm의 플라스틱 용기에 약 1.5 cm 높이로 담고 흡수선량 감쇠율을 평가하였다. 조사 조건은 골반 촬영 조건을 기준으로 5회 반복 측정하였고 측정한 조사선량 값을 흡수선량 값으로 변환한 뒤 평균값을 산출 비교하였다. 영상 정보 손실 정도는 팬텀의 골반강 부위를 차폐하고 획득한 영상을 근골격 전문의 2명과 방사선사 8명이 주요 해부학적 구조물의 관찰 정도를 평가 후 선택하였다. 또한 차폐한 부위의 영상에서 표현되는 골격과 가스의 신호 강도 차이를 분석한 결과 방사선 감쇠 효율성은 수용성 요오드 조영제의 비율이 높을수록 높은 차폐 효율을 나타냈다. 영상 정보의 손실 평가에서 평가자들은 수용성 요오드 조영제 20 ml 혼합물에서 해부학적 구조물의 관찰이 용이하다 평가하였으며 60 ml 이상의 혼합물에서는 구조물의 관찰이 불가능하였다. 골격과 가스의 신호강도 차이는 p < 0.001로 평균값의 차이가 유의미한 차이가 있었으며, 조영제의 농도가 높을수록 신호 강도의 차이는 적었다. 수용성 요오드 조영제 차폐체는 방사선 감쇠 효율이 기존의 차폐체 보다 떨어지지만, 차폐체가 관찰하는 목적부위 이거나 가까이 위치하여 차폐체를 적용하지 못하는 경우에 사용한다면, 영상 손실을 최소화하며 보다 더 적극적인 방사선 방호의 역할을 수행할 수 있다.