• Title/Summary/Keyword: Clearance Level

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Effect of Hepatic Cirrhosis on the Pharmacokinetics of Theophylline in Rats

  • Nam, Bang-Hyun;Sohn, Dong-Hwan;Ko, Geonil;Kim, Jae-Baek
    • Archives of Pharmacal Research
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    • v.20 no.4
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    • pp.318-323
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    • 1997
  • The experimental hepatic cirrhosis was induced either by bile duct ligation (BDL) or by pretreatment with dimethyinitrosamine (DMNA). The pharmacokinetics of theophylline were studied after a single intravenous or a single oral administration. Using the ultrafiltration method, protein-drug binding experiments were also carried out. The bilirubin level was several-fold increased by BDL, but not by DMNA treatment. The albumin content was decreased in both cirrhotic groups. The total clearance (Clt, ml/kg/hr) of theophylline in both hepatic cirrhosis groups significantly decreased and the terminal half-life $(t_{1/2})$ in the cirrhotic rats was increased about two-fold after intravenous and oral administration. The volume of distribution at steady state (Vdss, ml/kg) was increased slightly in the cirrhotic groups. Protein binding in BDL $(8.67{\pm}4.85%)$ decreased about four-folds, but in DMNA $(73.00{\pm}9.85%)$ similar result war observed as compared with the control. Increased free fraction of theophylline did not increase the volume of distribution in BDL. Therefore decreased total body clearance of theophylline was mainly due to decreased intrinsic clearance of theophylline in the liver. The absolute bioavailability of theophylline in these experiments was between 63.8 and 72.8%(66.1% in BDL, 63.8% in Sham operated and Control, 72.8% in DMNA). These results suggest that in the experimental hepatic cirrhosis model, administration route does not affect the disposition of theophylline.

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Pharmacokinetics and Renal Excretion of Sulfamethoxazole in Sheep

  • Shah, Bukhtiar;Mawaz, M.;Ijaz-Javed;Anwar-ul-Hassan-Gilani
    • Archives of Pharmacal Research
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    • v.12 no.3
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    • pp.154-159
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    • 1989
  • Pharmacokinetics and urinary excretion of sulfamethoxazole were investigated in healthy sheep. From the plasma disappearance curves after intravenous bolus injection (50 mg/kg), the half-life and volume of distribution were found to be 76 $\PM$14 min and 0.41 $\PM$ 0.18 lit/kg respectively. Body clearance was 4.06 $\PM$ 1.03 ml/kg/min. Very low Concentration of ddrug was present in plasma after 3 hours of administration and plasma level at 6 hour was only 4.4 $\PM$ 2.0 $\mu$g/ml. The renal clearance of sulfamethoxazole (22 $\PM$ 2.17 ml/min/10 kg) exeeded the creatinine clearance (9.78 $\PM$ 1, 57 ml/min/ 10 kg) which may be due to involvement of active tubular secretion and pH dependent back diffusion. Half of the dose of sulfamethoxazole was excreted as unchanged free drug while acetylated amine comprised of 20 percent within the first 6 hours of drug administration.

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A Study on the Establishing of Single Window System for Simplification of Trade Procedures (무역절차 간소화를 위한 Single Window 구축에 대한 연구)

  • Song, Seon-Uk
    • International Commerce and Information Review
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    • v.7 no.4
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    • pp.157-177
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    • 2005
  • In many countries, a Single Window system for simplifications is establishing in order to reduce works submitted double data and compliance costs. A Single Window is defined as a facility that allows parties involved in trade and transport to lodge standardized information and documents with a single entry point to fulfil all import, export, and transit-related regulatory requirements. A Single window can bring improved level of security, faster clearance and reduced compliance costs. UN/CEFACT released "Recommendation and Guidelines on establishing a Single Window to enhance the efficient exchange of information between trade and government". Also, WCO has made progress several projects to assist effective establishing a single window, i.e. CDM, UCR, ICT. Korea has being established a single window system, "e-trade platform" connected with trade, clearance, logistics, marketing and payment system. Some suggestions to establish a effective single window system in Korea are as follows. Firstly, it is necessary to clearly define roles and responsibilities of a lead agency in a single window system and form a organic relationship with PGA. Secondly, a single window system has to be progressed by stages, namely, customs clearance portal system should be established first, and later established e-trade platform. Lastly, the Korean government has to take part in CDM project to gain an advantage over other countries.

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The Risk of Trip and Fall by Characteristics of the Minimum Toe Clearance in the Middle-aged (중·고령자의 최소발끝높이 특성에 따른 걸려 넘어짐 위험성)

  • Park, Jae Suk;Byeon, Jung Hwan
    • Journal of the Korean Society of Safety
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    • v.34 no.5
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    • pp.132-138
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    • 2019
  • Fall accident is the most frequent accident type of occupational accidents. As the age of workers increases, trip and fall accident increases more than other types of occupational accident in the middle-aged group. In this study, the gait characteristics of 25 middle-aged participants (mean ages 47.4, S.D. 5.8) were studied to analyze the trip and fall risks. The Minimum toe clearance(MTC) against the floor surface was measured in the variable conditions of gait speed by a motion capture system. In the 50s age group, the MTC decreased and the MTC tended to reduce the variation with increasing walking speed in the level walking. Therefore, the trip and fall risks for the 50s age group is higher than the 40s age group. Especially, the faster walking speed will increase the trip and fall risks even more.

A new proposal for controlled recycling of decommissioning concrete waste as part of engineered barriers of a radioactive waste repository and related comprehensive safety assessment

  • In Gyu Chang;Jae Hak Cheong
    • Nuclear Engineering and Technology
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    • v.55 no.2
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    • pp.530-545
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    • 2023
  • As an alternative to conventional management options for a lot of concrete waste from decommissioning of nuclear power plants, a set of scenarios for controlled recycling of decommissioning concrete waste as engineered barriers of a radioactive waste repository was proposed, and a comprehensive safety assessment model and framework covering both pre-and post-closure phases was newly developed. The new methodology was applied to a reference vault-type repository, and the ratios of derived concentration limits to unconditional clearance levels of eighteen radionuclides for controlled recycling were provided for three sets of dose criteria (0.01, 1, and 20 mSv/y for the pre-closure and 0.01 mSv/y for the post-closure phases). It turns out that decommissioning concrete waste whose concentration is much higher than the unconditional clearance level can be recycled even when the dose criterion 0.01 mSv/y is applied. Moreover, a case study on ABWR bio-shield shows that the fraction of recyclable concrete waste increases significantly by increasing the dose criterion for the radiation worker in the pre-closure phase or the duration of storage prior to recycling. The results of this study are expected to contribute to demonstrating the feasibility of controlled recycling of a lot of decommissioning concrete waste within nuclear sectors.

Residual Radioactivity Investigation & Radiological Assessment for Self-disposal of Concrete Waste in Nuclear Fuel Processing Facility (콘크리트 폐기물의 자체처분을 위한 잔류방사능 조사 및 피폭선량평가)

  • Seol, Jeung-Gun;Ryu, Jae-Bong;Cho, Suk-Ju;Yoo, Sung-Hyun;Song, Jung-Ho;Baek, Hoon;Kim, Seong-Hwan;Shin, Jin-Seong;Park, Hyun-Kyoun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.2
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    • pp.91-101
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    • 2007
  • In this study, domestic regulatory requirement was investigated for self-disposal of concrete waste from nuclear fuel processing facility. And after self-disposal as landfill or recycling/reuse, the exposure dose was evaluated by RESRAD Ver. 6.3 and RESRAD BUILD Ver.3.3 computing code for radiological assessments of the general public. Derived clearance level by the result of assessments for the exposure dose of the general public is 0.1071Bq/g (3.5% enriched uranium) for landfill and $0.05515Bq/cm^2$ (5% enriched uranium) for recycling/reuse respectively. Also, residual radioactivity of concrete waste after decontamination was investigated in this study. The result of surface activity is $0.01Bq/cm^2\;for\;{\alpha}-emitter$ and the result of radionuclide analysis for taken concrete samples from surface of concrete waste is 0.0297Bq/g for concentration of $^{238}U$, below 2w/o for enrichment of $^{235}U$ and 0.0089Bq/g for artificial contamination of $^{238}U$ respectively. Therefore, radiological hazard of concrete waste by self-disposal as landfill and recycling/reuse is below clearance level to comply with clearance criterion provided for Notice No.2001-30 of the MOST and Korea Atomic Energy Act.

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A Study on the Clarance Level for the Metal Waste from the KRR-1 & 2 Decommissioning (연구로 1,2호기 해체 금속폐기물의 규제해제농도기준(안) 도출을 위한 연구)

  • 홍상범;이봉재;정운수
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.660-664
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    • 2003
  • The exposure dose form recycling on a large amount of the steel scrap from the KRR-1&2 decommissioning activities was evaluated, and also the clearance level was derived. The maximum individual dose and collective dose were evaluated by modifying internal dose conversion factor which was based on the concept of effective dose in ICRP 60, applied to the RESRAD-RECYCLE ver 3.06 computing code, IAEA Safety Series III-P-1.1 and NUREG-1640 as the assessment tool. The result of assessment for individual dose and collective dose is 23.9 ${\mu}Sv$ per year and 0.11 man$\cdot$Sv per year respectively. The clearance levels were ultimately determined by extracting the most conservative value form the results of the generic assessment and specific assessment methodologies. The result of clearance level for radionuclides($Co^60$, $Cs^137$) is less than $1.67{\times}10^{-1}$ Bq/g to comply with the clearance criterion(maximum individual dose : 10 $\muSv$ per year, collective dose : 1 man$\cdot$Sv per year) provided for Korea Atomic Energy Act and relevant regulations.

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Effects of Pulp Pre-treatment and Grinder Clearance on the Manufacturing Characteristics of Microfibrillated Cellulose (펄프의 전처리 및 그라인더 간격이 MFC 제조 특성에 미치는 영향)

  • Yong, Seong Moon;Kwak, Gun Ho;Cho, Byoung-Uk;Lee, Yong Kyu;Won, Jong Myoung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.2
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    • pp.61-69
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    • 2015
  • A number of researches have been carried out regarding the utilization of nanocellulose(crystalline nanocellulose, microfibrillated cellulose, nanofibrillated cellulose) for the manufacture of various kinds of composites and functional products. However, only few research works on the manufacturing characteristics of nanocellulose could be found, although some companies started already the production of nanocellulose in commercial scale. However, the most important thing in commercializing of production and utilization of nanocellulose is to develop the economical and efficient process. Thus, this study was carried out in order to investigate the effects of refining, alkaline pre-treatment and grinder clearance on the characteristics of microfibrillated cellulose and energy consumption. There was no significant differences in crystalline index with the degree of microfibrillation. The initial fibrillation could be improved by refining pre-treatment, but its effect was not observed anymore since the fibrillation was done up to certain level by grinding. Refining pre-treatment did not improved the energy efficiency. Alkaline pre-treatment can be helpful because the swelling of pulp fiber will facilitate fibrillation. It was found that the decrease in grinder clearance was helpful to improve the energy efficiency.

Analysis on the Effects of Sunshine Environment by Overpass Structure in Urban Areas (도시부 고가구조물에 의한 일조환경 영향분석)

  • Kum, Ki-Jung;Kim, Jong-Bo;Choi, Yong-Gil;Kim, Young-Jun
    • International Journal of Highway Engineering
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    • v.11 no.4
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    • pp.49-58
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    • 2009
  • Current sunshine regulations of our country, focused on common houses and general construction, are failing to reflect adequately the characteristics of roads and elevated structures. Besides, researches are chiefly being conducted on a pitch between common houses and its diverse effects, neglecting clearance between a road or elevated structure and a residential area, environmental elements brought on by structures, such as sunshine difficulty, and their resultant factors Therefore, this study, focused on the sunshine environment of elevated structures adjacent to a residential district, as part of all roads and elevated structures, looked over currently used clearance adequacy level and analyzed the characteristics of structures in relation to an angle of direction. Then, clearance ratio by heights was calculated through a pitch by characteristics of a structure. With a view to minimize the sunshine difficulty that might occur in the future construction, it aims to propose the basic data needed for calculating the minimum clearance, while emphasizing the necessity for institutional alignment on structures.

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Effect of Sodium Taurodeoxycholate on Biliary Excretion of Amaranth as an Anionic Model Drug in Rats (음이온 모델 화합물 아마란스의 담즙배설에 미치는 타우로데옥시콜레이트의 영향)

  • Shim, Chang-Koo;Chung, Suk-Jae
    • Journal of Pharmaceutical Investigation
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    • v.16 no.3
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    • pp.110-117
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    • 1986
  • Plasma disappearance of amaranth (AM), a model compound of organic anionic drugs, was retarded by intravenous infusion of taurodeoxycholate (TDC), a representative bile acid, in the rat. Biliary excretion accounted for 30-60% of the systemic excretion of AM. AM seemed to be metabolised in the hepatocyte to form a compound that is excreted more rapidly into the bile than AM itself, considering apparent biliary clearance, $CL_{bil}$, is much larger than systemic clearance, $CL_s$. Decrease in $CL_{bil}$ by TDC infusion might be due to elevated plasma level rather than decreased biliary excretion of AM. Decreased distribution or urinary excretion of AM by TDC was supposed to be one of the probable reasons of elevated plasma level. Competitive inhibition between AM and TDC on tissue distribution and urinary excretion might explain the mechanism. The effect of TDC on the $CL_{bil}$ of methylene blue, a cationic dye, was quite different from that of AM, as reported previously by us. More intensive study would be necessary to elucidate the difference of biliary excretion between organic anions and cations.

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