• 제목/요약/키워드: stability period

검색결과 1,552건 처리시간 0.028초

Ketorolac Ester Enhancer-prodrugs: Preparation and Evaluation of Their Physicochemical Properties

  • Yun, Sung-Il;Kim, Jung-Sun;Yong, Chul-Soon
    • Journal of Pharmaceutical Investigation
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    • 제38권6호
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    • pp.405-412
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    • 2008
  • Six ester analogues of Ketorolac were synthesized as potential enhancer prodrugs for transdermal delivery. Solubility of these esters was determined in 10% propylene glycol (PG)/isotonic phosphate buffer (IPB) at room temperature while lipophilicity was obtained as partition coefficients (log P) and capacity factors (k') using HPLC. Stability of the prodrugs in skin extract and in plasma was investigated at $37^{\circ}C$. The lipophilicity of the potential prodrugs increased in proportion to their alkyl chain length. Good linear relationship between partition coefficients (log P) and capacity factors (log k') was observed ($R^2=0.9961$). All of the analogues were fairly stable but slowly degraded in IPB over a 12 hour period. However, their stability in skin extract and in plasma varied with most compounds gradually decomposing over a 12 hour period. Although unsaturation of the alkyl ester chain did not alter the over all lipophilicity of the compound, the half-life was significantly affected. In plasma, degradation of the esters was slower than in the skin extract, which is a desirable trait for enhancer-prodrugs. However, the overall hydrolysis in the skin extract needs to be facilitated for the development of an effective enhancer prodrug. The analogue with the shortest half life in the skin extract was the unsaturated C-12 analogue of 0.96 hr.

포도파괴 Anthocyanin 색소의 분리 및 안전성 (Isolation and Stability of Anthocyanin Pigments in Grape Peels)

  • 심기환;강갑석;최진상;서권일;문주석
    • 한국식품영양과학회지
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    • 제23권2호
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    • pp.279-286
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    • 1994
  • Anthocyanins were isolated and identified from grape peels which were wasted much in Korea, and their characteristics were as follows .Isolated pigments from grape peels were 11 varieties such as 5 varieties of 3, 5-diglucoside (DG), 6 varieties of 3-monoglucoside (MG), and acylated pigment was 2 varieties of them. Malvidin was 4 varieties , petunidin , peonidin and delphinidin 2 varieties in each, and cyanidin 1 variety of 11 vareities. Malvidin -3, 5-diglucoside and peonidin -3, 5-diglucoside of anthocyanins were above 48% in total anthocyanins content of 114.99mg/g in dried skins. Breakdown of anthocyanins was higher become intimate neutral pH, but stable to stroage period for 7-days. Hyperchromic effects were showed when sugars were added in pigment extract of grape peels, the highest value was glucose and the next ordor was fructose and sucrose. Breakdown velosity of anthocyanins was higher when ascorbic acid was added, but its velocity was reduced in anaerobic state . Absorption degree by organic acid treatment was higher than control, and anthocyanins were stable to storage period for 7 days.

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Basic Analysis for Improvement of Mooring Stability Under Long Wave Impact

  • Ha, Chang-Sik;Moon, Seung-Hyo;Lee, Joong-Woo
    • 한국항해항만학회지
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    • 제41권5호
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    • pp.329-336
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    • 2017
  • This study suggests a general process of analyzing the mooring and cargo handling limit waves, which is an incident to the new energy port under long wave agitation. To reduce damages of ships and harbor structures due to strong wave responses, it is necessary to predict the change of wave field in the mooring berth to make the proper decision by dock master. The berthing area at a new LNG port in the east coast of Korea in this study is frequently affected by oscillations from waves of 8.5~13s periods in the wintertime. The long period waves give difficulties on port operation by lowering the annual berthing ratio. It needs to find the event waves from the real time offshore wave records, which cause over the mooring limits. For that purpose, the wave records from field measurement and offshore wave buoy were analyzed. From numerical simulation, the response characteristics of long period waves in the berthing area were deduced with or without breakwater expansion plan, analyzing the offshore field wave data collected for two years. Some event wave cases caused over the cargo handling and mooring limits as per the standard Korean port design guideline, and those were used for the decision of port operation by dock master, comparing with the real time offshore wave observations.

Efficacy of immune-strengthening functional drinks in top-level athletes: a questionnaire survey-based research

  • Lee, Minchul;Lee, Jin-Sook;Kim, Kyunghee;Kim, Chanju
    • 운동영양학회지
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    • 제25권3호
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    • pp.23-27
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    • 2021
  • [Purpose] Functional beverages are intended to support those who want to maintain optimal physical condition and improve their quality of life through the enhancement of heart health, immunity, and digestion. The purpose of this study was to investigate the performance of top-level athletes consuming immune-strengthening conditioning nutritional drinks. [Methods] A total of 107 top-level athletes (baseball (56 players), pro volleyball (17), athletics (16), cycling (8), golf (6), and fencing (6)) participated in the experiment. They consumed an immune-enhancing functional beverage once a day for 8 weeks and responded to a survey before, during, and after drinking the beverage. [Results] Three total aspect-based subfactors were drawn from 24 questions in the factor analysis: physical, satisfaction with mental stability, and activity in performance. The physical, mental stability and performance changes of athletes significantly increased in period 2 (4 weeks after intake) and period 3 (after 8 weeks of intake). [Conclusion] We evaluated the efficacy of a new conditioned beverage containing Lactobacillus B240 and protein in improving the performance and physiological utility of top athletes. This functional drink may gain popularity among those seeking health benefits and improved exercise performance.

Long-term Stability after Reduction of Mandible Fracture by Keyhole Plate: Evaluation at the Time of Plate Removal

  • Cheon, Kyeong-Jun;Cho, Seoung-Won;Jang, Won-Seok;Kim, Ju-Won;Yang, Byoung-Eun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제42권
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    • pp.6.1-6.6
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    • 2020
  • Background: Various types of miniplates have been developed and used for the reduction of facial bone fractures. We introduced Yang's Keyhole (YK) plate, and reported on its short-term stability. The purpose of this study was to evaluate the long-term stability of the YK plate, as a follow-up study, by examining the patients who had used the YK plate among the patients with the reduction of mandible fractures and who visited for plate removal. Methods: We reviewed the medical records of 16 patients who underwent mandibular fracture fixation using a YK plate (group I) and 17 patients who underwent mandibular fracture fixation using a conventional plate (group II). Assessment was then made on malunion, occlusal stability, discomfort during the application, and clinical symptoms. Results: From January 2015 to December 2017, a total of 36 patients underwent mandibular fracture surgery using a YK plate. A total of 16 patients received plate removal. Among them, 15 were male and 1 female. The average age was 26 years. The applied surgical sites were the 12 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of YK plate was an average of 335 days. During the same period, 45 people underwent surgery on the conventional plate. A total of 17 patients received plate removal. Among them, 15 were male and 2 females. The average age was 36 years. The applied surgical sites were the 8 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of the conventional plate was an average of 349 days. No malocclusion occurred at the time of removal, and occlusion was stable. No patient complained of joint disease or discomfort. Conclusion: The YK plate system, in which the screw was first inserted and the plate was applied, for clinical convenience did not cause any particular problem and no significant difference from the conventional plate.

4 족 보행로봇의 보행방법에 대한 에너지효율 (The Energy Efficiency of Walking Method for Quadruped Walking Robot)

  • 신창록;김장섭;박종현;유홍희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.882-887
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    • 2008
  • In this paper, the dependency of energy efficiency on the walking/running pattern and the walking/running period is analyzed though simulations of walk, trot and gallop. A quadruped animal has its own original features in the walking pattern and the walking period for adaptation to the environment. The robot model used in the simulations has three active joints and one passive spring-loaded joint at each leg, which is based on the actual quadruped robot, HUNTER (Hanyang UNiversity TEtrapod Robot), developed in the lab. Also included is the dependency of energy efficiency on the walking period in trot.

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DC 모터 시스템을 위한 짧은 샘플링 시간을 갖는 이산슬라이딩 모드의 최종 수렴범위 (The Ultimate Bound of Discrete Sliding Mode Control System with Short Sampling Period for DC Motor System)

  • 박흠용;조영훈;박강박
    • 제어로봇시스템학회논문지
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    • 제16권3호
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    • pp.245-248
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    • 2010
  • Almost all of control schemes proposed so far have been designed in the continuous-time domain theoretically. Actual systems, however, have been implemented in the discrete-time domain since Micro Control Unit(MCU) and/or microprocessors have been used for the controllers. Thus, the overall system turned to be a sampled-data system, and generally speaking, the ultimate error cannot converge to zero in the actual system even though the proposed control algorithm showed the asymptotic stability in the continuous-time domain. In this paper, therefore, the ultimate error bound of a sampled data system with a short sampling period has been investigated. The ultimate error is shown to be related in the sampling period.

이조시대 사랑방 가구에 대한 현대인의 미의식 (Aesthetic Characteristic of‘Sarangbang’Furniture of The Yi-dynasty Period)

  • 유영희
    • 대한가정학회지
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    • 제24권4호
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    • pp.139-146
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    • 1986
  • The purpose of this study was to identify aesthetic concepts of‘Sarangbang’furniture during the Yi-dynasty period and aesthetic descriptions indicating each concept expressed by experts in traditional furniture. The furniture selected for the study includes desks, table bookcases, document and stationary boxes (mungab), letter holders (Kobi) and inkstone boxes (younsang) with lacquer and oil finish on. The respondents were 72 traditional furniture experts; researchers collectors, sellers and artists related to period furniture. The important points of aesthetic descriptors were collected 123 from related literature. From experts' answers, 47 representative descriptors were selected. Data were analyzed with the SPSS using frequency, Percentage mean, factor analysis, t-test and C2. The results were as follows; 1. The aesthetic concept of sarangbang furniture during the Yi-dynasty can be categorized into 9 aspects; appearance of beauty, stability the interior space, naturalness, nobleness/harmony of lines, detail/refinement, simplicity, diversity solidity and surface division. 2. The characteristics of the Korean traditional furniture can be described using 47 descriptors explaining 9 concepts mentioned above.

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Study on Mahāsammata Model of Kingship in Mrauk U Period(1430-1784)

  • Aung, Zaw Lynn
    • 수완나부미
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    • 제7권2호
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    • pp.177-196
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    • 2015
  • This study on Mahāsammata Model of Kingship in Mrauk U Period from the 15th to 18th centuries attempts to demonstrate how the kings of Mrauk U or royal officials tried to claim this legitimating model of kingship and how they accepted this model of kingship and under what conditions the legitimate order of this model was lost. Vital to the adaptation of Mahāsammata model of kingship in the Mrauk U period is the claim that Mrauk U's rulers were direct lineal descendants of the first Buddhist king of the world, Mahāsammata and thence the clan of Gotama Buddha, Sākiya clan. This ideological model of kingship has a recognizable effect on the political stability of Mrauk U kingdom. While the Mahāsammata model of kingship performed as a belief of legitimizing kingship within the arena of royal court, the kings of Mrauk U tried to perform the related models of Mahāsammata, the ideal models of Buddhist kingship as dhammarāja and a cakkavatti. However, the conditions that fail to maintain the Mahāsammata model of kingship saw the weakening of the other related models of kingship, which eventually led to the decline of the kingdom.

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증기발생기 수위 제어를 위한 디지탈 제어기의 적정 샘플링 주기 (Optimal Sampling Period of the Digital Control System for the Nuclear Power Plant Steam Generator Water Level Control)

  • Hur, Woo-Sung;Seong, Poong-Hyun
    • Nuclear Engineering and Technology
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    • 제27권1호
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    • pp.8-17
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    • 1995
  • 최근 디지탈 기술을 응용하여 원자력 발전소 제어 시스템의 성능을 향상시키려는 많은 노력이 있어 왔고, 차세대 원자로에 구현할 것을 목표로 디지탈 제어 시스템 개발에 관한 장기적인 계획이 수립되어 있다. 디지탈 제어 시스템을 구축하고자 할 때 적정한 샘플링 주기를 정하는 것은 중요한 과정이다. 제어기의 안정성과 성능은 샘플링 주기에 밀접한 관련이 있다 현재 디지탈 제어기의 샘플링 주기를 체계적으로 정하는 전형적인 방법은 없다. 일반적으로 디지탈 제어기의 안정성을 고려해서 연속시간역 제어의 대역폭의 20∼30배의 역수 정도의 샘플링 주기를 흔히 쓴다. 이 논문에서는 안정성 뿐 아니라 시간역에서의 좋은 성능을 보장받을 수 있는 적정한 샘플링 주기를 얻을 수 있는 방법을 제시하였다. 이 방법으로 Irving의 모델을 이용하여 디지탈제어기의 적정 샘플링 주기를 예측하고, 고리 2호기의 마이크로 시뮬레이터와 WDPF 디지탈 제어기를 이용한 증기 발생기 수위제어 모사시스템에서 검증해 본 결과, 고리 2호기 원자력발전소 중기 발생기 수위제어를 위한 디지탈 제어기의 원자로 전 출력영역에 대한 적정 샘플링 주기 가 1초가 되는 것을 알게 되었다.

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