• 제목/요약/키워드: anti-phase

검색결과 903건 처리시간 0.027초

소목(蘇木) 물추출물의 G2/M기 정지를 통한 U937세포의 성장억제 효과 (Caesalpinia sappan L. Induces G2/M Phase Cell Cycle Arrest in Human Lymphoma U937 Cells)

  • 전병제;주성민;양현모;김보현;김원신;전병훈
    • 동의생리병리학회지
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    • 제24권1호
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    • pp.55-60
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    • 2010
  • Caesalpinia sappan L. (C. sappan) has long been used in traditional medicine as an emmenagogue, hemostatic and anti-inflammatory agent. The present study investigated the effects of water extract of C. sappan in human lymphoma U937 cells. The proliferation of U937 cells was decreased by C. sappan in a dose-dependently manner. Anti-proliferative effect of C. sappan on U937 cells was associated with G2/M phase arrest, which was mediated by regulating the expression of p21 protein. Moreover, phosphorylation of JNK and p38 was increased by C. sappan. Blockade of JNK and p38 was significantly inhibited C. sappan-induced G2/M phase arrest. Taken together, these results suggest that Anti-proliferative effect of C. sappan on U937 is assocated with G2/M phase cell cycle arrest by expression of p21 protein and, JNK and p38 activation.

Rahnella aquatilis AY2000균 유래의 항 효모물질의 작용양상 (Action Pattern of Anti-Yeast Substance Originated from Rahnella aquatilis Strain AY2000)

  • 박혜지;강민정;이종환;김광현
    • 미생물학회지
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    • 제47권2호
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    • pp.163-166
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    • 2011
  • 항 진균제의 인체에 대한 부작용을 완화시키는 방법은 부작용이 적은 새로운 항 진균제 개발이나 기존 항 진균제와 혼용하여 상승효과를 나타내는 물질이 필요하다. 이를 위해 Rahnella aquatilis AY2000가 생산하는 항 효모물질은 일종의 단백질성 고분자 물질이란 점에서 기존 항 진균제와 차이가 있다. 이 항 효모물질은 유도기나 대수증식 기에 있는 효모 생육을 억제시켰으며, cell cycle 분석에서 sub-G1기에 속하는 세포수의 증가 없이 세포를 arrest시켰다. 따라서 항 효모물질은 Candida albicans에 정균작용을 나타내었다. 또한 in vitro 실험에서 이 항 효모물질과 itraconazole이나 fluconazole을 병용한 후 fractional inhibitory concentration index 분석을 행한 결과 항 효모활성이 더욱 상승되었다. 결론적으로 이 항 효모물질은 정균 작용을 가질 뿐만 아니라 azole계의 항 진균제와 혼용하면 상승효과를 가짐으로 부작용이 적은 새로운 개념의 항 진균제로 개발할 가치가 있을 것이라고 생각된다.

Active Frequency with a Positive Feedback Anti-Islanding Method Based on a Robust PLL Algorithm for Grid-Connected PV PCS

  • Lee, Jong-Pil;Min, Byung-Duk;Kim, Tae-Jin;Yoo, Dong-Wook;Yoo, Ji-Yoon
    • Journal of Power Electronics
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    • 제11권3호
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    • pp.360-368
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    • 2011
  • This paper proposes an active frequency with a positive feedback in the d-q frame anti-islanding method suitable for a robust phase-locked loop (PLL) algorithm using the FFT concept. In general, PLL algorithms for grid-connected PV PCS use d-q transformation and controllers to make zero an imaginary part of the transformed voltage vector. In a real grid system, the grid voltage is not ideal. It may be unbalanced, noisy and have many harmonics. For these reasons, the d-q transformed components do not have a pure DC component. The controller tuning of a PLL algorithm is difficult. The proposed PLL algorithm using the FFT concept can use the strong noise cancelation characteristics of a FFT algorithm without a PI controller. Therefore, the proposed PLL algorithm has no gain-tuning of a PI controller, and it is hardly influenced by voltage drops, phase step changes and harmonics. Islanding prediction is a necessary feature of inverter-based photovoltaic (PV) systems in order to meet the stringent standard requirements for interconnection with an electrical grid. Both passive and active anti-islanding methods exist. Typically, active methods modify a given parameter, which also affects the shape and quality of the grid injected current. In this paper, the active anti-islanding algorithm for a grid-connected PV PCS uses positive feedback control in the d-q frame. The proposed PLL and anti-islanding algorithm are implemented for a 250kW PV PCS. This system has four DC/DC converters each with a 25kW power rating. This is only one-third of the total system power. The experimental results show that the proposed PLL, anti-islanding method and topology demonstrate good performance in a 250kW PV PCS.

개선된 DFT을 이용한 무효전력변동 단독운전 검출기법의 성능 개선 (Performance Improvement of an Anti-Islanding Algorithm using the Variation of Reactive Power with an Improved DFT Method)

  • 강덕홍;최대근;이교범
    • 전력전자학회논문지
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    • 제15권3호
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    • pp.179-187
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    • 2010
  • 본 논문에서는 무효전력변동기법을 사용하여 단독운전을 검출을 하기 위해서 선행되어야 하는 주파수 검출 방법 중에서 개선된 이산푸리에변환(Discrete Fourier Transform; DFT), 즉 Goertzel 알고리즘을 이용한 단독운전 검출기법을 제안한다. 실제 태양광 발전 시스템의 설치를 위해서는 전기사고나 시스템에 악영향을 유발하는 단독운전 검출기법의 연구가 선행되어야 한다. 적용하는 주파수 검출방법은 Goertzel 알고리즘을 이용한 기법으로 기존의 영점검출기법과 가상의 2상 PLL(Phase Locked Loop)에 비하여 외란의 영향에 강인하며 빠른 검출이 가능하다. 시뮬레이션 및 실험을 통하여 기존의 주파수검출기법인 영점검출기법과 가상의 2상 PLL을 이용한 주파수 검출과 제안하는 알고리즘을 비교하고 그의 우수성을 검증하였다.

증폭된 광 귀환을 가자는 다중 전극 복소 결합 DFB 레이저에서 발생되는 self-pulsation 특성 해석 (Analysis of Self-Pulsation Characteristics in Multi-Section Complex-Coupled DFB Lasers With Amplifying Optical Feedback)

  • 김상택;김태영;김부균;임영안;박경현
    • 한국광학회지
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    • 제16권6호
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    • pp.527-534
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    • 2005
  • 하나의 DFB 영역, 위상 조정 영역과 이득 영역으로 구성된 다중 전극 DFB 레이저의 pulsation 동작 특성을 살펴본다. Anti-phase (AP) complex-coupled (CC) DFB 구조를 사용한 경우가 in-phase CC DFB 구조나 index-coupled DFB 구조를 사용한 경우에 비하여 안정된 pulsation 동작이 발생하는 이득 영역과 위상 조정 영역의 전류 범위가 큼을 알 수 있다. AP CC DFB 구조를 사용한 경우 결합 세기가 커질수록, 이득 결합 계수가 커질수록 안정된 pulsation 동작이 발생하는 이득 영역의 전류 범위가 증가하고 pulsation 주파수의 튜닝 영역이 커짐을 볼 수 있다. 또한 위상 조정 영역의 위상 변화에 의한 pulsation주파수의 튜닝 영역도 커짐을 볼 수 있다. 고정된 결합 세기에서 DFB 영역의 길이가 증가할수록 pulsation 동작이 발생하는 위상 조정 영역과 이득 영역의 전류 범위가 증가하여 pulsation 주파수 튜닝 영역이 넓어짐을 볼 수 있다.

집파리유충 hemolymph 중신형의 anti-fungal peptides의 분리정제 (Isolation and Purification of Novel Anti-Fungal Peptides from Hemolymph of Immunized Larvae of Housefly, Musca domestica)

  • ;;;성창근
    • 생명과학회지
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    • 제16권3호
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    • pp.387-395
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    • 2006
  • 유도된 집파리유통 hemolymph중에서 Candida albicans의 3가지 anti-fungal peptides를 분리하였다. 3개 anti-fungal peptides는 분자량이 4-16 kDa 사이의 분명한 구별이 있을 뿐만 아니라, 각 peptide는 anti-fungal peptides작용이 있었다. 이들 peptide의 공통 특징은 모두 열을 받은 뒤 활성이 변하지 않는 비교적 강한 내열성을 보여주었다.

Anti-inflammatory, anti-ulcer and hypoglycaemic activities of ethanolic and crude alkaloid extracts of Madhuca indica (Koenig) Gmelin seed cake

  • M, Seshagiri;RD, Gaikwad;KS, Jyothi;S, Ramchandra;S, Paramjyothi
    • Advances in Traditional Medicine
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    • 제7권2호
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    • pp.141-149
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    • 2007
  • Madhuca indica has been used ethnomedically in Indian folks. In the present study we have investigated anti-inflammatory, anti-ulcer and hypoglycaemic effect of ethanolic extract (EE) and crude alkaloid extract of Madhuca indica seed cake on albino rats. The study showed that the EE had a significant, dose dependent anti-edematogenic, anti-ulcerogenic and hypoglycaemic activity, whereas the crude alkaloid extract exhibited a significant only. Both the extracts possess dose dependent inhibitory activity on carrageenan-induced edema, inhibiting prostaglandins or mediators involved in prostaglandin synthesis, the second phase of inflammation. The EE was significantly effective in protecting pylorus-ligation-induced gastric ulcers at a higher dose level. The active principle of EE seems to be a selective inhibitor of the COX II (prostaglandin synthesis) without important effect on COX I since, EE exhibited both anti-edematogenic and anti-ulcerogenic effect. The EE was effective in reducing the plasma glucose level in normal albino rats in a dose dependent manner, producing hypoglycaemic effect by stimulating the release of insulin from the ${\beta}-cells$ and/or increasing the uptake of glucose from the plasma.

급성통증 유발 흰쥐에 대한 위령선약침(威靈仙藥鍼)의 통증 억제효과 (Analgesic Effect of Clematidis Radix (CR) Herbal-acupuncture on the Test Rats with Induced Acute Pain)

  • 최원주;김기봉;김경호;김장현
    • Journal of Acupuncture Research
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    • 제26권6호
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    • pp.91-100
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    • 2009
  • Objectives : The objective of this study is to investigate Anti-nociceptive and anti-inflammatory effects of Clematidis Radix (CR) herbal-acupuncture on the test rats with induced acute pain. Methods : The effects of Clematidis Radix (CR)-distillates were investigated in three types of models with three different pain. Highly purified distillate of CR called CR herbal-acupuncture was injected to Zusanli ($ST_{36}$) acupoint. In the tail flick test, the CR herbal-acupuncture treatment did not show a significant effect of relieving acute pain. To investigate the anti-inflammatory effect of CR herbal-acupuncture, the second testing model'pain was induced by injecting formalin to its planter. For the last model, carrageenan was injected into tarsal joint. the medicinal effect of CR herbal-acupuncture was evaluated through the behavioral analyses such as licking time, weight distribution ratio and ankle circumference. Results : In the formalin test, the analgesic effect of CR herbal-acupuncture was more pronounced in the late phase (for 20 min after the early phase) than in the early phase (for the first 10 min post formalin injection). It was proven by weight distribution ratio testing and ankle edema testing that herbal-acupuncture of CR inhibited arthritis caused by the carrageenan. Conclusions : These results revealed that CR herbal-acupuncture was effective to alleviate the inflammatory pain and could be used as an analgesic treatment with an anti-inflammatory effect.

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The Effects of Exercise-based Cardiac Rehabilitation Phase II on Pro- and Anti-inflammatory Markers in Patients with Acute Coronary Syndrome

  • Kim, Al-Chan;Oh, Jae-Keun;Shin, Kyung-Ah;Kim, Young-Joo
    • 대한의생명과학회지
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    • 제19권1호
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    • pp.61-69
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    • 2013
  • The aim of this study was to evaluate the effect of exercise-based cardiac rehabilitation on pro- and anti-inflammatory markers in patients with acute coronary syndrome (ACS). ACS patients who underwent percutaneous coronary intervention (PCI) and took medicine during phase II of rehabilitation were recruited for study. Subjects were divided into two groups; exercise group (EX, n=21) and a non-exercise group (non-EX, n=13). Supervised exercise program in hospital consisted of treadmill and bicycle exercise was performed three times per week for 6 weeks. Patients of EX received individual counseling, including knowledge of heart disease, risk factor modification, and physical training. Cardiopulmonary fitness, body composition, and biochemical blood factors were analyzed before and after experiment. There was no significant difference in serum levels of hs-CRP and TGF-${\beta}1$ between groups, and between time intervals. But there was a significant decrease in serum levels of IL-18 (P<.001). And there was a significant increase in ratio of IL-18 to IL-10 (P<.01) and serum levels of IL-10 (P<.001). After cardiac rehabilitation, there was significant increase in exercise duration (P<.001), maximal oxygen uptake ($VO_{2peak}$; P<.001) and decrease in submaximal rate-pressure product (sRPP; P<.05) in EX. In conclusion, exercise-based cardiac rehabilitation during phase II in patients with ACS after PCI decreased serum IL-18 (pro-inflammatory) content and ratio of IL-18 to IL-10 in serum (highly related with disease recurrence), and increased serum IL-10 (anti-inflammatory) content. In addition, it led to improved cardiopulmonary fitness.

FQTR : RFID 시스템을 위한 새로운 하이브리드 태그 충볼 방지 프로토콜 (FQTR : Novel Hybrid Tag Anti-Collision Protocols in RFID System)

  • 정승민;조정식;김성권
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제36권7호
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    • pp.560-570
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    • 2009
  • RFID 기술은 바코드를 대체할 자동인식 기술로서 인식 속도가 빠르고 비접촉 방식으로 오염에 강한 장점을 가지고 있다. 그러나 RFID 기술의 대중화를 위해서는 선결되어야할 난제들이 있다. 이 중 본 논문에서는 다중 태그 식별 문제를 다룬다. 다중 태그를 인식하고 충돌을 방지하는 문제는 RFID 시스템의 성능에 직접적인 영향을 준다. 본 논문에서는 기존의 알고리즘들을 분석하고 개선하된 새로운 태그 충돌 방지 알고리즘을 제안한다. 제안된 알고리즘은 ALOHA 기반 알고리즘과 QT 기반 알고리즘의 하이브리드 형태로 분배와 인식 과정에 적합한 특성들을 혼합하여 구성하였다. 분배 과정에서는 ALOHA 방식을 이용하여 인식과정에서 한 프레임에 인식해야할 태그 수를 줄였다. 이는 Tree 의 깊이가 깊어져 지연을 일으키는 문제를 해결하였다. 인식 과정에서는 QT 기반 알고리즘을 이용하여, ALOHA 방식에서 모든 태그를 인식하지 못하는 문제를 해결하였다. 또한, 실제 RFID 환경을 분석하여 더 좋은 성능을 보이도록 태그ID 의 역순으로 인식하는 QTR 알고리즘을 적용하였다. 본 논문에서 제안하는 FQTR 알고리즘은 시뮬레이션 결과 기존의 알고리즘에 비해 뛰어난 성능을 보여주었다.