• 제목/요약/키워드: high dose rate

검색결과 887건 처리시간 0.035초

Uptake efficiencies of PCB 153 in fathead minnows through food chain of sediment-midge-fish

  • Park, Kyungho;Peter G. Meier
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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    • pp.162-165
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    • 2003
  • Uptake efficiencies of PCB 153 in fathead minnow through food chain of sediment-midge-fish were evaluated. Contaminated fish food, the midge Chironomus plumosus was prepared by exposing to sediments with PCB 153. We could harvest the midges with body PCB 153 levels of ∼ 1.0 mg/g and ∼ 10.0 mg/g, respectively, in 2 wk of exposure. PCB 153 level in fish fed with midge of 10.0 mg/g PCB 153 (high-dose group) reached its highest at 11.2 mg/g after 30 d of exposure. However, PCB level in fish fed with midge of 1.0 mg/g PCB 153 (low-dose group) kept increasing following first order rate kinetics until the end of exposure (38 d). When the fish food was changed to the uncontaminated ones, the fish body PCB levels were stabilized in ∼ 3 wk. The uptake efficiency in high-dose fish group was 37%, whereas low-dose group was 55%. Uptake efficiencies in fathead minnows were notably lower than that of pike (∼ 70%). This finding suggests that the uptake efficiency of this PCB congener may depend on the amount of the PCB in diet.

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Mongolian Gerbil의 뇌허혈 유발에 따른 뇌조직 손상에 있어서 사향 함유 우황청심원액과 영묘향 함유 우황청심원액의 조직학적 효능 비교 (The comparison of histological effects of musk containing and civet containing WooHwangChungSimWon on the cerebral ischemia)

  • 최은욱;이장헌;신상덕;마응천
    • Biomolecules & Therapeutics
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    • 제8권3호
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    • pp.255-261
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    • 2000
  • WooHwangChungSimWon is a traditional prescription for treating with hypertension, arteriosclerosis, coma, and stroke in China, Korea, and Japan. In the new presciption of WooHwangChungSimWon, the covet is substituted for the musk, the major component of WooHwangChungSimwon, because of the prohibition law about the musk. We have made a comparative study of the effects on the ischemic damage between the musk containing and civet containing WooHwangChungSimWon. In order to investigate the effects of WooHwangChungSimWon on the ischemic damage, each samples were administrated for 12 days, ischemia was induced for 10 minutes at 7th day, and immunohistochemistry was performed in the region of hippocampus of mongolian gerbils. According to the result of immunohistochemistry, the survival rates of neuroal cells in the hippocampal CA1 region are 37.8% in the high dose of musk containing WooHwangChungSimWon (HM-WHCSW) administrated group, 27.8% in low dose of civet containing WooHwangChungSimWon (LC-WHCSW), and 35.5% in high dose of civet containing WooHwangChungSimWon (HC-WHCSW) administrated group. These survial rates were significantly different from the survival rate of sham control group (14.4%). The results suggest that all the samples except the low dose of musk containing WooHwangChungSimWon (LM-WHCSW) have protective or preventive effects on cerebral ischemia.

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High-dose lipopolysaccharide induced autophagic cell death in bovine mammary alveolar cells

  • Park, Jin-Ki;Yeo, Joon Mo;Cho, Kwanghyun;Park, Hyun-Jung;Lee, Won-Young
    • 한국동물생명공학회지
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    • 제37권3호
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    • pp.169-175
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    • 2022
  • Bovine mammary epithelial (MAC-T) cells are commonly used to study mammary gland development and mastitis. Lipopolysaccharide is a major bacterial cell membrane component that can induce inflammation. Autophagy is an important regulatory mechanism participating in the elimination of invading pathogens. In this study, we evaluated the mechanism underlying bacterial mastitis and mammary cell death following lipopolysaccharide treatment. After 24 h of 50 ㎍/mL lipopolysaccharide treatment, a significant decrease in the proliferation rate of MAC-T cells was observed. However, no changes were observed upon treatment of MAC-T cells with 10 ㎍/mL of lipopolysaccharide for up to 48 h. Thus, upon lipopolysaccharide treatment, MAC-T cells exhibit dose-dependent effects of growth inhibition at 10 ㎍/mL and death at 50 ㎍/mL. Treatment of MAC-T cells with 50 ㎍/mL lipopolysaccharide also induced the expression of autophagy-related genes ATG3, ATG5, ATG10, ATG12, MAP1LC3B, GABARAP-L2, and BECN1. The autophagy-related LC3A/B protein was also expressed in a dose-dependent manner upon lipopolysaccharide treatment. Based on these results, we suggest that a high dose of bacterial infection induces mammary epithelial cell death related to autophagy signals.

감마선 조사에 의한 쌀저장에 관한 연구 (제 5 보) - 감마선 조사 쌀에 대한 저온 저장의 영향 - (Studies on the Preservation of Korean Rice by Gamma-radiation (V) -Effects of low temperature storage of gamma-irradiated rice-)

  • 김형수;김성기
    • 한국식품과학회지
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    • 제3권1호
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    • pp.19-24
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    • 1971
  • 경기도 김포지방에서 수확한 농림6호를 1970년 3월에 현미와 백미로 표준도정하여 kraft paper bag에 포장하고 Co-60 irradiator로 30, 50, 600 및 800 Krad의 조사한후 저온($10^{\circ}C$, 75% RH)에 저장하면서 fat acidity, amylase activity, 백미가루와 그 전분의 amylogram에 의한 viscosity 및 식미시험 등의 시험 결과는 다음과 같다. 1) Fat acidity의 증가는 $30{\sim}50\;Krad$ 조사미에 있어서 대조구에 비해서 근소한 차이였으나, $600{\sim}800\;Krad$ 조사구에서는 현저하게 증가하였고, 상온 저장에 비해서는 그 증가율이 낮았다. 2) Amylase activity는, $30{\sim}50\;Krad$ 조사구에서 대조구와 차이가 없고, 모두 감소경향이며, $600{\sim}800\;Krad$ 조사구는 그 감소경향이 현저하다. 3) Brabender amylogram에 의한 viscosity는 백미분의 경우 $30{\sim}50\;Krad$ 조사구는 대조구와 차이없이 저장중 약간 감소경향이고, $600{\sim}800\;Krad$ 조사구는 현저하게 그 viscosity가 감소하였다. 4) 식미시험 결과는 $30{\sim}50\;Krad$ 조사구가 대조구와는 차이가 없고, $600{\sim}800\;Krad$ 조사구는 색깔에서만 대조구와 유의차를 나타냈다.

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진단적 방사성옥소 전신스캔이 음성인 갑상선 재발암의 진료 (Management of Recurrent Thyroid Carcinoma with Negative Diagnostic Radioiodine Whole-Body Scan)

  • 정준기
    • 대한핵의학회지
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    • 제35권3호
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    • pp.117-124
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    • 2001
  • Serum thyroglobulin measurement and I-131 whole-body scintigraphy (WBS) are well-established methods for the detection of recurrence in the follow-up of patients with thyroid carcinoma. However, inconsistent results are observed frequently, and these two methods are not always able to detect recurrence. In some patients, serum thyroglobulin level is elevated but the WBS is negative, because the recurrent tumor is too small and below the sensitivity of the diagnostic scan, or there is a dissociation between thyroglobulin synthesis and the iodine frapping mechanism. In such cases, various nuclear imaging methods including Tl-201 Tc-99m-sestamibi, and F-18-FDG PET can be used besides anatomical imaging methods. Among them, FDG PET localizes recurrent lesions in WBS-negative thyroid carcinoma with high accuracy. Several studies have suggested that empirical high-dose I-131 therapy resulted in a high rate of visualization in post-therapy scans with evidence of subsequent improvement. An important question is when to operate on patients with recurrent tumor. We believe that surgical removal is the best means of treatment for patients with localized persistent tumor, despite the high-dose I-131 therapy. with tumor in thyroid remnant, and with isolated recurrence in the lymph node, lung or bone. In addition, we recommend palliative resection of locally unresectable mass with subsequent treatment with high-dose I-131 therapy. Before I-131 therapy, the evaluation of sodium-iodide symporter expression in thyroid carcinoma can predict iodine uptake. Retinoic acid is known to induce redifferentiation, and to enhance I-131 uptake in thyroid carcinoma. Retinoic acid therapy may represent an alternative approach before high-dose I-131 therapy.

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Sensitivity of Lavender to Proton, Electron, and Gamma Radiation

  • Chen, Wensheng;Li, Hui;Shi, Lei;Bai, Hong Tong
    • 원예과학기술지
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    • 제34권1호
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    • pp.122-133
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    • 2016
  • While ion beams are widely used in plant breeding, little is known about the sensitivity of Lavandula angustifolia (lavender) to ionizing radiation. To compare the biological effects of different types of ionizing radiation on the germination and survival rates of lavender, we exposed lavender seeds to gamma rays, 3 MeV electron beams, and 1.89 MeV proton ion beams. We observed that the seed germination rate decreased with increasing dosages of all three types of ionizing radiation. The malformation rate of lavender seedlings exposed to electron beams and gamma rays increased with increasing radiation dosage. By contrast, the effect of the accelerated proton beams on the malformation rate was negatively correlated with the dosage used. The survival rate of lavender seedlings exposed to the three types of ionizing radiation decreased in a dose-dependent manner. In addition, the survival rate of seedlings irradiated with proton and electron beams decreased more slowly than did that of seedlings irradiated with gamma rays. The half-lethal dose of gamma rays, electron beams, and proton beams was determined to be 48.1 Gy, 134.3 Gy, and 277.8 Gy, respectively, and the most suitable proton-ion energy for lavender seeds in terms of penetration depth was determined to be 5 MeV. These findings provide valuable information for the breeding of lavender by radiation mutation.

Comparison of the hemodynamic effects of propofol and ketamine as anesthetic induction agents during high-dose remifentanil administration: a single-center retrospective comparative study

  • Sanuki, Takuro;Mishima, Gaku;Kurata, Shinji;Watanabe, Toshihiro;Kiriishi, Kensuke;Tachi, Mizuki;Ozaki, Yu;Okayasu, Ichiro;Kawai, Mari;Matsushita, Yuki;Miura, Keiichiro;Ayuse, Takao
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제15권3호
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    • pp.129-134
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    • 2015
  • Background: We hypothesized that ketamine, when administered as the anesthetic induction agent, may prevent cardiovascular depression during high-dose remifentanil administration, unlike propofol. To test our hypothesis, we retrospectively compared the hemodynamic effects of ketamine, during high-dose remifentanil administration, with those of propofol. Methods: Thirty-eight patients who underwent oral surgery at the Nagasaki University Hospital between April 2014 and June 2015 were included in this study. Anesthesia was induced by the following procedure: First, high-dose remifentanil ($0.3-0.5{\mu}g/kg/min$) was administered 2-3 min before anesthesia induction;next, the anesthetic induction agent, either propofol (Group P) or ketamine (Group K), was administered. Mean arterial pressure (MAP) and the heart rate were recorded by the automated anesthesia recording system at four time points: immediately before the administration of high-dose remifentanil (T1);immediately before the administration of propofol or ketamine (T2);2.5 min (T3), and 5 min (T4) after the administration of the anesthetic induction agent. Results: In Group P, the MAP at T3 ($75.7{\pm}15.5mmHg$, P = 0.0015) and T4 ($68.3{\pm}12.5mmHg$, P < 0.001) were significantly lower than those at T1 ($94.0{\pm}12.4mmHg$). However, the MAP values in the K group were very similar (P = 0.133) at all time points. The heart rates in both Groups P (P = 0.254) and K (P = 0.859) remained unchanged over time. Conclusions: We showed that ketamine, when administered as the anesthetic induction agent during high-dose remifentanil administration, prevents cardiovascular depression.

중재적 방사선 시술 시 환자선량에 대한 참고 준위 비교 (Reference levels for patient Radiation Dose in interventional radiological procedures)

  • 박혁;김용완;전주섭
    • 한국방사선학회논문지
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    • 제6권1호
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    • pp.11-17
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    • 2012
  • 중재적 방사선 시술 시 환자의 피폭선량을 시술별로 분류하여 측정 및 평가하여 안전관리 자료로 활용하고자 하였다. 검사는 시술별(TACE, EVAR, Iliac stent, Lower Limb, BAE, Embolization, PTBD, PTGBD, Abscess, Nephrostomy)로 투시시간, 면적선량, 영상획득이미지 수를 측정하였다. 시술별 분석결과 비혈관계 검사에서 전반적으로 낮은 값을 보였으며, 혈관계 검사에서는 IVC filter를 제외한 모든 검사에서 높은 값을 나타냈다. 투시시간은 EVAR가 24m30s로 가장 높았고, 면적선량 또한 EVAR가 236 $Gy/cm^2$로 가장 높았다. 면적선량률은 TACE가 22.8 $Gy/cm^2$로 높게 나타났다. 이 결과를 토대로 중재적 방사선시술시 환자피폭선량에 대한 기준선량을 제시하고자 한다.

In Vitro Experiment to Evaluate 137Cs Dissolution in the Digestion Process of Mushrooms

  • Nishiono, Kanoko;Yamanishi, Hirokuni
    • Journal of Radiation Protection and Research
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    • 제45권4호
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    • pp.154-162
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    • 2020
  • Background: Several studies have reported that wild mushrooms contain high amounts of radioactive cesium (137Cs). After the Fukushima Daiichi Nuclear Power Plant Accident, a significantly high concentration of 137Cs has been detected in wild mushrooms, and their consumption may be the cause of the chronic internal exposure of local consumers to radioactivity. Therefore, an accurate evaluation of the internal radioactivity resulting from mushroom ingestion is needed. Materials and Methods: The 137Cs elution rate through the cooking and digestion stages was evaluated using in vitro experiments. The edible mushroom Pleurotus djamor was taken as a sample for the experiments. The mushrooms were cultivated onto solid media containing 137Cs. We evaluated the internal dose based on the actual conditions using the elution rate data. For various cooking methods, the results were compared with those of other wild edible mushrooms. Results and Discussion: From the elution experiment through cooking, we proved that 25%-55% of the 137Cs in the mushrooms was released during soaking, boiling, or frying. The results of a simulated digestion experiment after cooking revealed that almost all the 137Cs in the ingested mushrooms eluted in the digestive juice, regardless of the cooking method. The committed effective dose was reduced by 20%-75% when considering the dissolution through the cooking process. Conclusion: We found that cooking lowers 137Cs concentration in mushrooms, therefore reducing the amount of radioactivity intake. Besides, since there were differences between mushroom types, we demonstrated that the internal exposure dose should be evaluated in detail considering the release of 137Cs during the cooking stages.

옥수수 생육에 미치는 저선량 감마선 조사효과 (Influence of Low Dose Gamma Radiation on the Growth of Maize(Zea mays L.) Varieties)

  • 김재성;이영근;박홍숙;백명화;김동희
    • 한국환경농학회지
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    • 제19권4호
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    • pp.328-331
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    • 2000
  • 국내에서 재배중인 옥수수 재래종 (고성, 영월)품종의 종자에 저선량 ${\gamma}$선을 조사하여 초기생육과 수량에 미치는 영향을 온실과 포장실험으로 조사하였다. 저선량 방사선 조사가 옥수수 종자발아 및 초기생육에서 뚜렷한 촉진효과를 보였으나 품종별로 다소 차이가 있었으며 고성재래종은 2 Gy, 영월재래종은 12 Gy가 가장 효과적이었다. 포장생장과 수량에서도 저선량 조사에 의해 증가하는 경향을 보였는데 적정선량은 고성재래종은 8 Gy, 영월재래종은 $4{\sim}12$ Gy 범위로 나타났다.

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