• 제목/요약/키워드: Dose rate effect

검색결과 1,018건 처리시간 0.032초

백서 관상 혈류에 미치는 Phenylephrine 및 Clonidine 의 영향 (Influence of Phenylephrine and Clonidine on The Coronary Flow in Rats)

  • 김광호
    • Journal of Chest Surgery
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    • 제23권6호
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    • pp.1107-1117
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    • 1990
  • The regulatory role of the post \ulcorner1-and \ulcorner2-adrenoceptors on cardiac function, particularly in coronary flow rate, was investigated in the isolated rat heart treated with 10-6 M propranolol. When introduced into the left atrium of the heart, phenylephrine[10-7-10-2 M] decreased coronary flow rate and increased mean coronary resistance in a dose related fashion, but did not affect heart rate. Methoxamine also elicited the increment of coronary resistance and the decrement of coronary flow rate, though the effects of methoxamine were weaker than those by phenylephrine. The effect of phenylephrine was inhibited by 1\ulcornerM prazosin and shifting the dose-response curve to the right. The effects of clonidine, a selective \ulcorner2-adrenoceptor agonist, were studied in the heart taken from reserpinized rats. Clonidine increased coronary resistance, decreased heart rate and coronary flow rate with a dose-dependent manner. These effects were abolished by 10-6 M yohimbine, a selective \ulcorner2-antagonist, and were not affected by 10-6M prazosin. Clonidine also decreased coronary flow and increased mean coronary resistance in electric paced heart. These effects were inhibited by rawoulscine, a selective ca-antagonist. These results indicate that the stimulation of both post \ulcorner1-and \ulcorner2-adrenoceptor causes coronary vasoconstiction. And it is inferred that this model of sympathomimetics-induced coronary vasospasm may provide a useful tool for investigating spasmolytic agents which are of benefit in the treatment of variant angina.

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중재적 방사선 분야 방호용구 차폐효과 (Shielding Effect of Radiation Protector for Interventional Procedure)

  • 고신관;강병삼;임청환
    • 대한방사선기술학회지:방사선기술과학
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    • 제30권3호
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    • pp.213-219
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    • 2007
  • 중재적 시술의 시술자를 대상으로 방사선 방호용구의 안과 밖의 실제 방사선량을 측정하여 이를 바탕으로 방사선 방호용구의 방사선 차폐율을 비교 분석하는 것이다. 2005년 5월부터 9월까지 중재적 시술 중에서 시행 빈도가 높은 TACE, PTBD를 시행하는 중재적 시술자 4인에게 방사선 방호용구의 착용 시 피폭선량 감쇄효과를 측정하기 위해 각 신체부위별 방호용구 안과 밖에 TLD를 부착하여 피폭선량을 측정하였다. TLD 부착부위는 Goggle inside, Goggle outside, Thyroid protector inside, Thyroid protector outside, Apron inside(waist level), Apron outside(upper chest level), Hand 4th finger(ring type TLD)와 환경방사선을 측정하기 위해 TLD 10개를 Control room 여러 곳에 위치시켰다. TACE 검사시 0.07 mmPb Goggle의 사용으로 연속투시방식에서는 평균 53.8%의 선량율감쇄를 보였으며 펄스투시방식에서는 77.6%의 감쇄효과를 보였고, 0.5 mmPb Thyroid protector의 사용에서는 연속투시방식에서는 평균 88.9%의 선량율감쇄를 보였으며 펄스투시방식에서는 92.8%로 선량율감쇄에서는 유의한 차이가 없었다. PTBD 검사시 0.07 mmPb Goggle의 사용으로 평균 62.7%의 선량율감쇄를 보였으며, 0.5 mmPb Thyroid protector의 사용에서는 평균 89.1% 선량율이 감쇄 되었고 0.5 mmPb Apron의 사용에서도 평균 87.9%의 감쇄효과가 있었다. PTBD 시술은 TACE 시술에 비해 평균 투시시간은 6.14 min이나 적었으나 피폭선량은 체부에서 약 3배, 손에서는 40배 이상 피폭되었다. 납당량이 두꺼운 방호용구를 착용하거나 최소한 권고되어지는 0.5 mmPb 이상의 것을 착용하여야 하며, 시술시 눈을 보호하는 Goggle의 착용을 생활화해야 한다. 테이블 아래쪽에 납커튼을 장착하면 복부의 피폭선량율은 평균 38.4% 감쇄하므로 납커튼을 장착하여 산란선을 차폐하여야 한다. 펄스투시방식을 이용하면 연속투시에 비해 피폭선량율이 평균 59.0% 감쇄되므로 연속투시보다 펄스투시방식을 선택하여 피폭선량을 감소시켜야 한다.

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새로운 항암제 AG 60의 일반약리작용 (General Pharmacology of AG 60, a New Anticancer Drug)

  • 성연희;안희열;김선돈;이선애;조순옥;한영복
    • Biomolecules & Therapeutics
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    • 제5권4호
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    • pp.412-418
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    • 1997
  • General pharmacological properties of AG 60 (mixture of acriflavine and guanosine (1:1, w/w)), which has anticancer effect, following intramuscular administration were examined in terms of effects on central nervous system, gastrointestinal system, cardiovascular system, respiratory system and autonomic nervous system in mice, rats, guinea-pigs and rabbits. AG 60 at the dose of 15 mgtg had no influences on pentobarbital sleeping time, spontaneous motor activity, chemoshock produced by pentylenetetrazole solution, writhing syndromes induced by 0.8% acetic acid solution, and motor coordination of mice. However, AG 60 at the dose of 7.5 and 15 mg/kg caused significant decrease of normal body temperature 1 and/or 2 h after the administration. No influence on body temperature was observed at 3.75 mg/kg in mice. Gastric secretion of rat and intestinal motility of mice were not influenced by the dose of 15 mg/kg. In terms of autonomic nervous system, AG 60 did not show direct effect and inhibitory or augmentative action of histamine- or acetylcholine-induced contractions at the concentration of 5 mg/L in the isolated ileum of guinea-pig. The administration of 15 mg/kg of AG 60 did not affect mean arterial blood pressure and heart rate in rat. AG 60 (15 mg/kg) given to anesthetized rabbits showed no effect on respiratory rate.

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Vibrio vulnificus에 대한 경구용백신 CJ-50002의 일반약리작용 (General Pharmacology of CJ-50002, an Oral Vaccine against Vibrio vulnificus Infection)

  • 김영훈;정성목;신재규;최재묵;이나경;박완제;이윤하;이영수
    • Biomolecules & Therapeutics
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    • 제7권1호
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    • pp.89-96
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    • 1999
  • CJ-50002 is an oral vaccine against V.vulnificus infection composed of whole cell lysate of V. vulnificus. The general pharmacological properties of CJ-50002 were evaluated in various animals and in vitro system. CJ-50002 at oral doses of 0.2, 2 and 20 mg/kg had no effect on general behavior in mice, chromo- and electro-convulsions in mice, writhing syndrome induced by acetic acid in mice, body temperature in rats, charcoal meal propulsion in mice and urine and electrolytes excretion in rats. However, oral administration of CJ-50002 at dose of 20 mg/kg prolonged the hexobarbital-inuced sleeping inducing time in mice. In anesthetized dogs, CJ-50002 showed no effect on blood pressure, heart rate and ECG but decreased the respiratory rate and femoral blood flow at dose of 20 mg/kg. p.o. CJ-50002 had no effect on the contractile response of the isolated guinea pig ileum to various spasmogen at concentrations of 0.2, 2 and 20 $\mu\textrm{g}$/ml, respectively. Since these pharmacological effects of CJ-500o2 were observed at dose much greater than those in clinical use (approximately 0.16 mg/kg, p.o.), it is likely that this vaccine may be relatively free of undesirable effects in clinical practice.

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YH439의 알콜성 지방간생성 억제작용 (Decreased Induction of Alcoholic Fatty Liver by YH430 in Rats)

  • 강경애;김영철
    • Toxicological Research
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    • 제11권2호
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    • pp.267-271
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    • 1995
  • A single large dose of ethanol as well as chronic ethanol consumption produces alcoholic fatty liver in human and experimental animals. We examined the effects of YH439, a potential hepatoprotective agent, on alcoholic fatty liver generation in adult female rats. In rats treated with YH439 (250 mg/kg, po) 4 hr prior to a single dose of ethanol (6 g/kg, po), a significant decrease in hepatic triglyceride accumulation was observed. YH439 also has an inhibitory effect on hepatic triglyceride and cholesterol accumulation induced by repeated ethanol treatments for one week. Because it has been known that induction of alcoholic fatty liver is associated with lipid peroxidation and/or hepatic glutathione depression, the effect of YH439 on these parameters was determined in the livers of rats treated with ethanol. Coadministration with YH439 inhibited MDA formation and gIutathione depression induced by acute or repeated ethanol administration. In order to determine the effect of YH439 on ethanol metabolism in vivo, disappearance of ethanol from blood was measured. In rats treated with a single dose of ethanol (6 g/kg, po), the ethanol concentration in blood reached a peak approximately 120 min following the treatment which declined linearly for 18 hrs. YH439 had no effect on the decline of blood ethanol concentration regardless of the dose of ethanol given to rats. These results in this study suggest that YH439 has an inhibitory effect on fatty liver generation induced by acute or repeated ethanol consumption through a mechanism not directly related to the rate of ethanol metabolism in vivo.

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Quantitative Evaluation of Radiation Dose Rates for Depleted Uranium in PRIDE Facility

  • Cho, Il Je;Sim, Jee Hyung;Kim, Yong Soo
    • Journal of Radiation Protection and Research
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    • 제41권4호
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    • pp.378-383
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    • 2016
  • Background: Radiation dose rates in PRIDE facility is evaluated quantitatively for assessing radiation safety of workers because of large amounts of depleted uranium being handled in PRIDE facility. Even if direct radiation from depleted uranium is very low and will not expose a worker to significant amounts of external radiation. Materials and Methods: ORIGEN-ARP code was used for calculating the neutron and gamma source term being generated from depleted uranium (DU), and the MCNP5 code was used for calculating the neutron and gamma fluxes and dose rates. Results and Discussion: The neutron and gamma fluxes and dose rates due to DU on spherical surface of 30 cm radius were calculated with the variation of DU mass and density. In this calculation, an imaginary case in which DU density is zero was added to check the self-shielding effect of DU. In this case, the DU sphere was modeled as a point. In case of DU mixed with molten salt of 50-250 g, the neutron and gamma fluxes were calculated respectively. It was found that the molten salt contents in DU had little effect on the neutron and the gamma fluxes. The neutron and the gamma fluxes, under the respective conditions of 1 and 5 kg mass of DU, and 5 and $19.1g{\cdot}cm^{-3}$ density of DU, were calculated with the molten salt (LiCl+KCl) of 50 g fixed, and compared with the source term. As the results, similar tendency was found in neutron and gamma fluxes with the variation of DU mass and density when compared with source spectra, except their magnitudes. Conclusion: In the case of the DU mass over 5 kg, the dose rate was shown to be higher than the environmental dose rate. From these results, it is concluded that if a worker would do an experiment with DU having over 5 kg of mass, the worker should be careful in order not to be exposed to the radiation.

고방사선장내 작업 로봇용 이중 방사선 감지 시스템 (A Dual Radiation Monitoring System Ror Robot Working in High Radiation Field)

  • 이남호;조재완;김승호
    • 대한전기학회논문지:시스템및제어부문D
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    • 제54권9호
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    • pp.556-558
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    • 2005
  • The effect of high irradiation on inspection systems in a nuclear power plant can be severe, especially to electronic components such as control hoards. The effect may lead to a critical malfunction or trouble to a underwater robot for inspection and maintenance of nuclear reactor. However, if information on the total accumulated dose on the sensitive parts of the robot is available, a prediction of robot's behavior in radiation environments becomes possible. To know how much radiation the robot has encountered, a dosimeter to measure the total accumulated dose is necessary. This paper describes the development effort of a dual radiation monitoring system using a SiC diode as a dose-rate meter and a p-type power MOSFET as a dose meter. This attempt using two sensors which detect same radiation improves reliability and stability at high intensity radiation detection in nuclear facilities. It uses the concept of diversity and redundancy.

인조혈관 동정맥루의 혈액 투석량에 따른 인조혈관 내부 유동 특성에 관한 수치해석 연구 (NUMERICAL STUDY ON BLOOD FLOW CHARACTERISTICS IN A ARTERIOVENOUS GRAFT WITH DELIVERED DOSE DURING HEMODIALYSIS)

  • 김재열;노경철;유홍선
    • 한국전산유체공학회지
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    • 제16권4호
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    • pp.84-91
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    • 2011
  • Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics through arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

혈액 투석 시 주사침에서의 투석량에 따른 인조혈관 내부 유동 특성에 관한 수치해석 연구 (Numerical Study on Blood Flow Characteristics in a Arteriovenous Graft with Delivered dose During Hemodialysis)

  • 김재열;노경철;유홍선
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.469-476
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    • 2011
  • Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics though arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

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과배란처리 한우에서 초음파 유도에 의한 난자채란에 대한 연구 (Transyaginal Ultrasound-guided Oocytes Collection in Superovulated Korean Native Cows)

  • 이효종;강태영;조성근;박준규;손우진;최민철;최상용
    • 한국수정란이식학회지
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    • 제12권2호
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    • pp.195-202
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    • 1997
  • The present study was carried out to evaluate the effect of superovulation treatments on ovarian responses, oocyte recovery rates and grades of collected oocytes using an ultrasound-guided transvaginal approach in Korean native cows. Superovulation in cows was induced with two different regimenes: 1) FSH-decreasing dose(n=8): the cows were received twice per day for three days of the total dose of 400 mg of FSH-p, 2) FSH-single dose(n=9): the cows were administrated a single dose of 400 mg of FSH-p in 25% PVP. The Observation of visible follicles and collection of oocytes were performed 12 hours following the last FSH in FSH-decreasing dose group and 48 hours after the FSH-single dose injection. All visible follicles larger than 6 mm were punctured and aspirated with a 6.5 MHz convex-array ultrasound transducer designed for intravaginal use. The mean number of visible follicles(> 6 mm) was significantly(P<0.05) higher in the FSH-decreasing dose treatment (22.811.9) and FSH-single dose treatment (20.612.0) groups than the non-treatment group(7.0$\pm$8). The mean recovery rate of oocytes was not significantly(P<0.05) different between the treatment and control groups, but the mean number of collected oocytes was significantly(P<0.05) higher in the FSH-decreasing dose treatment( 12.611.5) and FSH-single dose treatment (11.813.6) groups than the non-treatment group(3.7$\pm$0.5). In conclusion, the FSH-single dose treatment at superovulation in cows for ultrasound-guided aspiration might increase the number of aspiratable follicles and the recovery rate of follicular oocytes as the FSH-decreasing dose treatment.

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