• 제목/요약/키워드: RHR

검색결과 48건 처리시간 0.027초

Involvement of Amino Acids Flanking Glu7.32 of the Gonadotropin-releasing Hormone Receptor in the Selectivity of Antagonists

  • Wang, Chengbing;Oh, Da Young;Maiti, Kaushik;Kwon, Hyuk Bang;Cheon, Jun;Hwang, Jong-Ik;Seong, Jae Young
    • Molecules and Cells
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    • 제25권1호
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    • pp.91-98
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    • 2008
  • The Glu/$Asp^{7.32}$ residue in extracellular loop 3 of the mammalian type-I gonadotropin-releasing hormone receptor (GnRHR) interacts with $Arg^8$ of GnRH-I, conferring preferential ligand selectivity for GnRH-I over GnRH-II. Previously, we demonstrated that the residues (Ser and Pro) flanking Glu/$Asp^{7.32}$ also play a role in the differential agonist selectivity of mammalian and non-mammalian GnRHRs. In this study, we examined the differential antagonist selectivity of wild type and mutant GnRHRs in which the Ser and Pro residues were changed. Cetrorelix, a GnRH-I antagonist, and Trptorelix-2, a GnRH-II antagonist, exhibited high selectivity for mammalian type-I and non-mammalian GnRHRs, respectively. The inhibitory activities of the antagonists were dependent on agonist concentration and subtype. Rat GnRHR in which the Ser-Glu-Pro (SEP) motif was changed to Pro-Glu-Val (PEV) or Pro-Glu-Ser (PES) had increased sensitivity to Trptorelix-2 but decreased sensitivity to Cetrorelix. Mutant bullfrog GnRHR-1 with the SEP motif had the reverse antagonist selectivity, with reduced sensitivity to Trptorelix-2 but increased sensitivity to Cetrorelix. These findings indicate that the residues flanking $Glu^{7.32}$ are important for antagonist as well as agonist selectivity.

Short- to mid-term outcomes of radial head replacement for complex radial head fractures

  • Baek, Chung-Sin;Kim, Beom-Soo;Kim, Du-Han;Cho, Chul-Hyun
    • Clinics in Shoulder and Elbow
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    • 제23권4호
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    • pp.183-189
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    • 2020
  • Background: The purpose of the current study was to investigate short- to mid-term outcomes and complications following radial head replacement (RHR) for complex radial head fractures and to identify factors associated with clinical outcomes. Methods: Twenty-four patients with complex radial head fractures were treated by RHR. The mean age of the patients was 49.8 years (range, 19-73 years). Clinical and radiographic outcomes were evaluated for a mean follow-up period of 58.9 months (range, 27-163 months) using the visual analog scale (VAS) score for pain, the Mayo elbow performance score (MEPS), the quick disabilities of the arm, shoulder and hand (Quick-DASH) score, and serial plain radiographs. Complications were also evaluated. Results: At the final follow-up, the mean VAS score, MEPS, and Quick-DASH score were 0.6±1.1, 88.7±11.5, and 19.4±7.8, respectively. The mean range of motion was 132.7° of flexion, 4.7° of extension, 76.2° of pronation, and 77.5° of supination. Periprosthetic lucency was observed in six patients (25%). Heterotopic ossification was observed in four patients (16.7%). Arthritic change of the elbow joint developed in seven patients (29.2%). Capitellar wear was found in five patients (20.8%). Arthritic change of the elbow joint was significantly correlated with MEPS (P=0.047). Four cases of complications (16.6%) were observed, including two cases of major complications (one stiffness with heterotopic ossification and progressive ulnar neuropathy and one stiffness) and two cases of minor complications (two transient ulnar neuropathy). Conclusions: RHR for the treatment of complex radial head fractures yielded satisfactory short- to mid-term clinical outcomes, though radiographic complications were relatively high.

심장재활 프로그램(Phase III)이 심근경색증 노인의 심혈관과 심폐기능에 미치는 효과 (Effects of Cardiac Rehabilitation Programs(Phase III) on Cardiovascular and Cardiorespiratory Function of the Elderly with Myocardial Infarction)

  • 김정선;김영주;정명호
    • 성인간호학회지
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    • 제21권2호
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    • pp.212-224
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    • 2009
  • Purpose: The purpose of this study was to examine the effects of the cardiac rehabilitation program(Phase III) on cardiovascular and cardiorespiratory function in the elderly (age, ${\geq}$ 60) who experienced acute myocardial infarction. Methods: The design of research was nonequivalent control group pretest-posttest design. Subjects were 10 people in the experimental group and 10 in the control group. The intervention program was the cardiac rehabilitation program(Phase III), and was performed for 50 ~ 60 minutes, twice a week for 8 weeks. The dependent variables were the cardiovascular and cardiorespiratory function. Results: Significant differences were shown in RHR, RSBP, SRPP, SBS, BMI, PT of the experimental group after the intervention. As for the differences in the amount of changes, there were differences among groups in RHR, RSBP, SRPP, SBS, PMET, and PT of the experimental group. Conclusion: The cardiac rehabilitation program(Phase III) may be effective in improving cardiovascular function and enhancing cardiorespiratory function in elderly patients with acute myocardial infarction.

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Remote Nozzle Blocking Device of RCS Pipe during Mid-Loop Operation in Nuclear Power Plants

  • Kang, Ki-Sig;Lee, Se-Yub;Chi, Ham-Chung
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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    • pp.571-576
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    • 1996
  • Currently most nuclear power plants(NPPs) are adopted the mid-loop operation to minimize the overhaul period and save the operating cost. For mid-loop operation it is essential to install nozzle dam between RCS pipe and steam generator(SG). Because SG remains more highly contaminated with radioactive material than any other parts of the NPPs, the repairmen are very reluctant to carry out installing nozzle dam inside the SG. Until now, unfortunately, it appears that no practically applicable device was developed to provide the longstanding demand. Also the accidents have been reported by licenser event report during this operation mode due to loss of residual heat removal(RHR). The purpose of this paper is to conduct remotely blocking and disintegration of nozzle of a SG which has the highest radiation exposure during the maintenance in NPPs. The remote nozzle blocking device of a SG includes three bladders, hubs, air controller provisions to supply and contact air pressure into the bladders. This remote nozzle block device will give the larger operation margin to prevent the loss of RHR and minimize the radiation exposure dose to the repairman and shorten the overhaul periods.

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Effect analysis of ISLOCA pathways on fission product release at Westinghouse 2-loop PWR using MELCOR

  • Kim, Seungwoo;Park, Yerim;Jin, Youngho;Kim, Dong Ha;Jae, Moosung
    • Nuclear Engineering and Technology
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    • 제53권9호
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    • pp.2878-2887
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    • 2021
  • As the amount of fission product released from ISLOCA was overestimated because of conservative assumptions in the past, several studies have been recently conducted to evaluate the actual release amount. Among several pathways for the ISLOCA, most studies were focused on the pathway with the highest possibility. However, different ISLOCA pathways may have different fission product release characteristics. In this study, fission product behavior was analyzed for various pathways at the Westinghouse two-loop plant using MELCOR. Four pathways are considered: the pipes from a cold leg, from a downcomer, from a hot leg to the outlet of RHR heat exchanger, and the pipe from the hot leg to the inlet of RHR pump (Pathway 1-4). According to the analysis results, cladding fails at around 2.5 h in Pathways 1 and 2, and on the other hand, about 3.3 h in Pathways 3 and 4 because the ISLOCA pathways affect the safety injection flow path. While the release amount of cesium and iodine ranges between 20 and 26% in Pathways 1 to 3, Pathway 4 allows only 5% to the environment because the break location is submerged. Also, as more than 90% of cesium released to the environment passes through the personnel door, reinforcing the pressure capacity of the doors would be a significant factor in the accident management of the ISLOCA.

Flow Characteristics Analysis for the Chemical Decontamination of the Kori-1 Nuclear Power Plant

  • Cho, Seo-Yeon;Kim, ByongSup;Bang, Youngsuk;Kim, KeonYeop
    • 방사성폐기물학회지
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    • 제19권1호
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    • pp.51-58
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    • 2021
  • Chemical decontamination of primary systems in a nuclear power plant (NPP) prior to commencing the main decommissioning activities is required to reduce radiation exposure during its process. The entire process is repeated until the desired decontamination factor is obtained. To achieve improved decontamination factors over a shorter time with fewer cycles, the appropriate flow characteristics are required. In addition, to prepare an operating procedure that is adaptable to various conditions and situations, the transient analysis results would be required for operator action and system impact assessment. In this study, the flow characteristics in the steady-state and transient conditions for the chemical decontamination operations of the Kori-1 NPP were analyzed and compared via the MARS-KS code simulation. Loss of residual heat removal (RHR) and steam generator tube rupture (SGTR) simulations were conducted for the postulated abnormal events. Loss of RHR results showed the reactor coolant system (RCS) temperature increase, which can damage the reactor coolant pump (RCP)s by its cavitation. The SGTR results indicated a void formation in the RCS interior by the decrease in pressurizer (PZR) pressure, which can cause surface exposure and tripping of the RCPs unless proper actions are taken before the required pressure limit is achieved.

고리1호기 계통제염을 위한 원자로냉각재내 유동 특성 평가 (Flow Characteristics Evaluation in Reactor Coolant System for Full System Decontamination of Kori-1 Nuclear Power Plant)

  • 김학수;김초롱
    • 방사성폐기물학회지
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    • 제16권3호
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    • pp.389-396
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    • 2018
  • 국내 가동원전 중 2-루프 가압경수로인 고리1호기는 약 40년 운전한 후, 2017년 6월 18일 영구정지되었다. 영구정지된 고리 1호기는 주요 해체작업을 수행하기전에 계통내 선량률을 저감시켜 작업자피폭을 최소화하기 위한 계통제염을 수행할 예정이다. 일반적으로, 계통제염 범위는 원자로압력용기, 가압기, 증기발생기, 화학 및 체적제어계통, 잔열제거계통 및 원자로 냉각재계통 주요배관을 포함한다. 이러한 계통 및 기기 등을 효율적으로 제염하기 위해서는 제염과정에서 원자로냉각재계통내 유동특성을 평가할 필요가 있다. 계통제염을 위해 순환유량을 제공하는 방법은 다양하나, 본 논문에서는 잔열제거펌프 운전에 따른 고리1호기 원자로냉각재계통내 유동특성을 평가하였다. 잔열제거펌프를 이용한 계통제염은 원자로냉각재 내 유량의 불균형을 초래하여 계통내 기기 및 배관 등에 불순물을 침적시켜 제염이 효율적이지 않다는 것으로 평가되었다.