• 제목/요약/키워드: AR-23

검색결과 285건 처리시간 0.019초

신수(BL23) 택사약침이 Cisplatin으로 유발된 급성신부전 백서에 미치는 영향 (Effects of Alismatis Rhizoma Pharmacopuncture at BL23 on Cisplatin-Induced Acute Renal Failure in Rats)

  • 김명식;김재홍;윤대환;정현우;조명래
    • Korean Journal of Acupuncture
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    • 제36권1호
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    • pp.63-73
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    • 2019
  • Objectives : This study was designed to investigate the effects of Alismatis Rhizoma (AR) pharmacopuncture at BL23 on acute renal failure induced by cisplatin. Methods : The Sprague-Dawley rats were divided into Normal group (no injection of cisplatin and no treatment), Control group (cisplatin injection without treatment), Acu group (needling at BL23 after cisplatin injection), AR-PA1 group (treated with $0.3571mg/kg/20{\mu}l$ of AR pharmacopuncture at BL23 after cisplatin injection), and AR-PA2 group (treated with $1.7855mg/kg/20{\mu}l$ of AR pharmacopuncture at BL23 after cisplatin injection). Each treatment was given once daily for 8 days. Changes in body weight, kidney weight, tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin-6 (IL-6), Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GPx), serum blood urea nitrogen (serum BUN), and serum creatinine were observed. Results : Body weight was significantly increased in AR-PA1 on $4^{th}$ and $6^{th}$ days and AR-PA2 on $2^{nd}$ day. $TNF-{\alpha}$ was significantly decreased in Acu, AR-PA1 and AR-PA2 groups. Cu-Zn SOD was significantly increased in AR-PA2 group. GPx was significantly increased in AR-PA1 and AR-PA2 groups. But kidney weight, IL-6, serum BUN and serum creatinine were not significantly changed in any groups compared to control group. Conclusions : In acute renal failure induced by cisplatin, AR pharmacopuncture has a mitigating effect on the inflammatory reaction related to the increase of $TNF-{\alpha}$ in the kidney tissue and a protective effect on the oxidative stress of the kidney tissue. However it is unlikely to restore the glomerular function or inhibit the renal swelling.

동아시아 대기의 강 탐지 알고리즘 비교 (Comparison of Atmospheric River Detection Algorithms in East Asia)

  • 김규리;백승윤;권예은;손석우
    • 대기
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    • 제33권4호
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    • pp.399-411
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    • 2023
  • This study compares the three detection algorithms of East Asian summer atmospheric rivers (ARs). The algorithms developed by Guan and Waliser (GW15), Park et al. (P21), and Tian et al. (T23) are particularly compared in terms of the AR frequency, the number of AR events, and the AR duration for the period of 2016-2020. All three algorithms show similar spatio-temporal distributions of AR frequency, centered along the edge of the North Pacific high. The maximum AR frequency gradually shifts northward in early summer as the edge of the North Pacific High expands, and retreats in late summer. However, the detailed pattern and the maximum value differ among the algorithms. When the AR frequency is decomposed into the number of AR events and the AR duration, the AR frequencies detected by GW15 and P21 are equally explained by both factors. However, the number of AR events primarily determine the AR frequency in T23. This difference occurs as T23 utilizes the machine learning algorithm applied to moisture field while GW15 and P21 apply the threshold value to moisture transport field. When evaluating AR-related precipitation, the ARs detected by P21 show the closest relationship with total precipitation in East Asia by up to 60%. These results indicate that AR detection in the East Asian summer is sensitive to the choice of the detection algorithm and can be optimized for the target region.

미래 육군합성전장훈련체계에 VR/AR 기술 적용방안 연구 (Study on the application of VR/AR technology to the future ROK Army Synthetic Battlespace Training System)

  • 이종훈;박준욱
    • 융합보안논문지
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    • 제23권5호
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    • pp.189-197
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    • 2023
  • 육군은 육군합성전장훈련체계를 2026년까지 개발하고, 이를 활용하여 사단급 LVC통합훈련을 발전시킬 계획이다. 본 연구에서는 육군합성전장훈련체계에 VR/AR 기술을 적용하여 훈련의 효과와 효율을 향상시킬 수 있는 방안을 제안하였다. 이를 위해, 선진국과 한국군의 국방 분야 VR/AR 기술 활용사례를 분석한 결과, 교육훈련 체계를 실감형으로 전환했을 때 교육훈련의 효과와 효율이 향상될 수 있음을 확인하였다. 이에 따라, VR/AR 기술 적용 대상 국방 교육훈련 과목을 선정하여 제시하였고, 육군합성전장훈련체계에 VR/AR 기술을 적용하기 위한 발전방향을 고찰한 다음, 육군합성전장 훈련체계에 VR/AR 기술을 적용하는 방안을 제안하였다.

RV-23, a Melittin-Related Peptide with Cell-Selective Antibacterial Activity and High Hemocompatibility

  • Zhang, Shi-Kun;Ma, Qian;Li, Su-Bo;Gao, Hong-Wei;Tan, Ying-Xia;Gong, Feng;Ji, Shou-Ping
    • Journal of Microbiology and Biotechnology
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    • 제26권6호
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    • pp.1046-1056
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    • 2016
  • RV-23 is a melittin-related antibacterial peptide (MRP) with lower cytotoxicity than either melittin or AR-23, another MRP. The aim of this study was to explore the mechanism of RV-23's antibacterial selectivity and its hemocompatibility. The results showed that all the peptides exhibited lytic activity against Staphylococcus aureus and Escherichia coli, with RV-23 showing the highest potency. Moreover, RV-23 had lower cytotoxicity than melittin or AR-23 at their minimal inhibitory concentration. In addition, CD experiments showed that melittin, RV-23, and AR-23 all had a typical α-helical structure, and RV-23 had the lowest α-helix content. The structural information showed that RV-23 has the lowest hydrophobicity and highest hydrophobic moment. Because hydrophobicity and α-helix content are believed to correlate with hemolysis, the results indicate that the selective lytic activity against bacteria of RV-23 may be due to its low hydrophobicity and α-helicity, which lead to low cytotoxicity without affecting antibacterial activity. Furthermore, RV-23 did not affect the structure and function of blood components such as red blood cells, platelets, albumin, and the blood coagulation system. In conclusion, RV-23 is a cell-selective antibacterial peptide with high hemocompatibility due to its unique structure.

O2/Ar 관측에 기반한 순군집생산량 추정 연구 동향 (Estimation of Net Community Production Based on O2/Ar Measurements)

  • 함도식;이인희
    • 한국해양학회지:바다
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    • 제23권1호
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    • pp.49-62
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    • 2018
  • 순일차생산량과 종속 영양 생물의 호흡량의 차이로 정의되는 순군집생산량(net community production; NCP)은 해양 생물펌프의 척도로 활용되고 있다. 이 논문에서 소개하는 $O_2/Ar$ 관측에 기반한 NCP 추정법($O_2/Ar-NCP$)은 연구선의 이동 중에도 1분 미만의 고빈도로 $O_2/Ar$를 연속적으로 측정할 수 있어, 신생산량 혹은 방출생산량 등 전통적인 생물펌프 척도가 갖는 시간 혹은 공간 해상도의 제한을 혁신적으로 개선한 것이다. 논문에서는 $O_2/Ar-NCP$ 방법의 이론적 배경과 실험 장치의 구성에 대해 설명하였다. 또한 기존 생물펌프 척도와 $O_2/Ar-NCP$의 비교, 대양의 해역별 NCP 분포, 현장 관측 결과와 기계학습을 결합한 전 대양 NCP의 추정, 식물 플랑크톤 군집 구조와 NCP 연관성 등에 관한 주요 연구 사례들을 소개하였다.

지속시간항을 갖는 AR HMM을 이용한 잡음환경에서의 강인 화자인식 시스템 구현 (Implementation of a Robust Speaker Recognition System in Noisy Environment Using AR HMM with Duration-term)

  • 이기용;임재열
    • 한국음향학회지
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    • 제20권6호
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    • pp.26-33
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    • 2001
  • 기존의 AR HMM(auroreg ressive hidden morkov model)에 의한 화자인식 방법은 그 성능이 우수하나, 잡음에 대한 것이 고려되지 않아 실제 환경에 적용시 성능저하가 문제가 된다. 본 논문에서는 실제 환경에 맞추기 위하여 관측 신호 모델에서 잡음을 고려하고, 화자인식 성능을 개선하고자 지속시간항 (duration-term)을 포함하는 AR HMM을 이용하여 잡음환경에서의 강인한 화자인식 시스템을 제안한다. 100명의 화자 (남자 77명, 여자 23명)가 2주에 걸쳐 6번 발성한 숫자음 데이터베이스을 가지고, 백색잡음 및 자동차 잡음하에서 실험한 결과, 제안된 방법으로 성능이 향상됨을 확인하였다.

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FCAW를 이용한 SM45C의 혼합가스비율에 따른 전류파형 및 용접특성 연구 (Analysis on the Characteristic of Current Waveform and Welding for SM45C Using FCAW According to Gas Mixture Ratio)

  • 이종훈;임병철;박상흡
    • 한국생산제조학회지
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    • 제23권6호
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    • pp.618-623
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    • 2014
  • This study, analyzed the waveform and mechanical properties of flux cored arc Welding on SM45C. $CO_2$ 10% + Ar 90% shows the lowest standard deviation and shunt ratio at which the arc was most stable. $CO_2$ 10% + Ar 90% is equal to $CO_2$ 20% + Ar 80%. therefore, $CO_2$ 20% + Ar 80% is the best of mixture gases. The hardness test result for the gas mixture ratio of $CO_2$ 10% + Ar 90% was HV 249.7 which is the highest measured value. According to tensile test results, the tensile strength increased with increasing Ar in the mixture gas. This was because of the inertness of the argon, which does not combine with other elements, causing $CO_2$ to combine with pearlite and ferrite and decreasing the maximum tensile strength. Microstructural examination results show that with increasing Ar, ferrite generation decreases while the mild microstructure increases which influences the hardness.

ω-κ 알고리즘을 이용한 SAR 영상의 방위각 방향 외삽 기법 연구 (A Study on the Azimuth Direction Extrapolation for SAR Image Using ω-κ Algorithm)

  • 박세훈;최인식;조병래
    • 한국전자파학회논문지
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    • 제23권8호
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    • pp.1014-1017
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    • 2012
  • 본 논문에서는 고해상도 SAR(Synthetic Aperture Radar) 영상 획득을 위해 방위각 방향 해상도를 향상시키기 위한 방법을 소개하였다. SAR 영상 획득을 위해 ${\omega}-k$(omega-k) 알고리즘을 이용하였으며, 2차원 주파수 영역에서 방위각 방향으로 AR(Auto-Regressive) 방법을 이용한 외삽을 이용하여 해상도를 향상시켰다. AR 방법은 선형 예측(linear prediction) 모델을 기반으로 한 외삽 기법이다. AR 방법을 이용한 외삽 기법 중에서 Burg 알고리즘을 이용하여 예측 차수(prediction order)와 표적의 거리에 따른 성능 비교 결과를 보여 준다.

Vibrational Structure and Predissociation of Ar-CO2 by CO2 Symmetric Stretching Mode Coupled with Ar Motion

  • Jung, Jae-Hoon;Sun, Ho-Sung
    • Bulletin of the Korean Chemical Society
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    • 제23권2호
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    • pp.245-252
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    • 2002
  • The computationally simple quantum mechanical method (VSCF-DWB-IOS) has been applied to studying the Ar-$CO_2$ vibrational predissociation phenomenon. The new methodology utilizes the vibrational self-consistent field method to determine the vibrational structure of the van der Waals complex, the distorted-wave Born approximation for dissociating process, and the infinite-order sudden approximation for the continuum dissociating product of $CO_2$. The dissociation due to the coupling of the symmetric stretching vibrational motion of $CO_2$ with the motion of the Ar van der Waals mode has been extensively investigated. The lifetimes of transient excited vibrational states, linewidths of absorption peak, and the rotational state distributions of the product, $CO_2$ have been computed. It has been found that the lifetime of the Ar-$CO_2$ in excited vibrational state is very long compared with that of triatomic van der Waals complexes and the product $CO_2$ carries a major portion of dissociation energy as a rotational energy.

Cl2/BCl3/Ar 플라즈마에서 반응성 이온들에 의해 식각된 ZnO 박막 표면 연구 (A Study of the Etched ZnO Thin Films Surface by Reactive Ion in the Cl2/BCl3/Ar Plasma)

  • 우종창;김창일
    • 한국전기전자재료학회논문지
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    • 제23권10호
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    • pp.747-751
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    • 2010
  • In the study, the characteristics of the etched Zinc oxide (ZnO) thin films surface, the etch rate of ZnO thin film in $Cl_2/BCl_3/Ar$ plasma was investigated. The maximum ZnO etch rate of 53 nm/min was obtained for $Cl_2/BCl_3/Ar$=3:16:4 sccm gas mixture. According to the x-ray diffraction (XRD) and atomic force microscopy (AFM), the etched ZnO thin film was investigated to the chemical reaction of the ZnO surface in $Cl_2/BCl_3/Ar$ plasma. The field emission auger electron spectroscopy (FE-AES) analysis showed an elemental analysis from the etched surfaces. According to the etching time, the ZnO thin film of etched was obtained to The AES depth-profile analysis. We used to atomic force microscopy to determine the roughness of the surface. So, the root mean square of ZnO thin film was 17.02 in $Cl_2/BCl_3/Ar$ plasma. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the plasmas.