• 제목/요약/키워드: Physiological Mechanism

검색결과 1,004건 처리시간 0.035초

Metallothioneins and oxidative stress

  • Beattie, John H.;Trayhurn, Paul
    • 한국영양학회:학술대회논문집
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    • 한국영양학회 2002년도 추계학술대회 및 총회
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    • pp.73-82
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    • 2002
  • The low molecular weight zinc-binding protein metallothionein (U) contains 32% cysteine and has been shown to efficiently scavenge hydroxyl radicals in vitro. MT expression is induced by oxidative stress and an antioxidant role for this protein has therefore been proposed. This review mainly focuses on the evidence for this role arising from studies using genetically modified animals and cells which either over- or under-express MT. Despite some considerable disparity of results in the literature, reported studies do generally support an antioxidant role. Nevertheless, oxidant stress at non-physiological treatment levels has been the preferred experimental model and there is little information about the role of MT in physiological oxidative stress. Although it is presumed that the mechanism by which MT has an antioxidant effect involves oxidation of cysteinal thiols, it is possible that zinc release from MT is in itself an important signalling factor.

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Overexpressed Mitochondrial Thioredoxin Protects PC12 Cells from Hydrogen Peroxide and Serum-deprivation

  • Lee, Yun-Song;Yu, Seung-A
    • The Korean Journal of Physiology and Pharmacology
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    • 제7권1호
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    • pp.33-37
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    • 2003
  • Oxidative damage to mitochondria is a critical mechanism in necrotic or apoptotic cell death induced by many kinds of toxic chemicals. Thioredoxin (Trx) family proteins are known to play protective roles in organisms under oxidative stress through redox reaction by using reducing equivalents of cysteines at a conserved active site, Cys-X-X-Cys. Whereas biological and physiological properties of Trx1 are well characterized, significance of mitochondrial thioredoxin (Trx2) is not well known. Therefore, we addressed physiological role of Trx2 in PC12 cells under oxidative stress. In PC12 cells, transiently overexpressed Trx2 significantly reduced cell death induced by hydrogen peroxide, whereas mutant Trx2, having serine residues instead of two cysteine residues at the active site did not. In addition, stably expressed Trx2 protected PC12 cells from serum deprivation. These results suggest that Trx2 may play defensive roles in PC12 cells by reducing oxidative stress to mitochondria.

Adenosine Induced Apoptosis in BHK Cells via P1 Receptors and Equilibrative Nucleoside Transporters

  • Sun, Wentian;Khoo, Hoon Eng;Tan, Chee Hong
    • BMB Reports
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    • 제38권3호
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    • pp.314-319
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    • 2005
  • Adenosine, as a ubiquitous metabolite, mediates many physiological functions via activation of plasma membrane receptors. Mechanisms of most of its physiological roles have been studied extensively, but research on adenosine-induced apoptosis (AIA) has only started recently. In this study we demonstrate that adenosine dose-dependently triggered apoptosis of cultured baby hamster kidney (BHK) cells. Adenosine-induced apoptotic cell death was characterized by DNA laddering, changes in nuclear chromatin morphology and phosphatidylserine staining. Apoptosis was also quantified by flow cytometry. Results suggest the involvement of adenosine $A_1$ and $A_3$ receptors as well as equilibrative nucleoside transporters in apoptosis induced by adenosine. These results indicate a receptor-transporter co-signaling mechanism in AIA in BHK cells. The involvement of $A_1$ and $A_3$ receptors also implies a possible apoptotic pathway mediated by G protein-coupled receptors.

생리적 신호를 이용한 통증 인식을 위한 딥 러닝 네트워크 (Deep Learning Network Approach for Pain Recognition Using Physiological Signals)

  • ;이귀상;양형정;김수형
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2021년도 추계학술발표대회
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    • pp.1001-1004
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    • 2021
  • Pain is an unpleasant experience for the patient. The recognition and assessment of pain help tailor the treatment to the patient, and they are also challenging in the medical. In this paper, we propose an approach for pain recognition through a deep neural network applied to pre-processed physiological. The proposed approach applies the idea of shortcut connections to concatenate the spatial information of a convolutional neural network and the temporal information of a recurrent neural network. In addition, our proposed approach applies the attention mechanism and achieves competitive performance on the BioVid Heat Pain dataset.

신경망을 이용한 다중 심리-생체 정보 기반의 부정 감성 분류 (Classification of Negative Emotions based on Arousal Score and Physiological Signals using Neural Network)

  • 김아영;장은혜;손진훈
    • 감성과학
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    • 제21권1호
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    • pp.177-186
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    • 2018
  • 감성은 복잡하고 다양한 요인들에 의해 영향을 받기 때문에 다각적인 측면에서 고려되어야 한다. 본 연구에서는 심리 평가 척도의 하나인 각성(arousal) 지표와 다중 생체신호에서 추출된 생체지표 반응을 이용하여 중립 및 부정 감성(슬픔, 공포, 놀람)의 분류하였다. 이를 위하여 감성에 따른 생체지표 반응의 차이를 확인하였고, 다중 신경망 알고리즘 기반의 감성 인식기를 적용하여 이들 감성이 얼마나 정확하게 분류되는가를 확인하였다. 총 146명의 실험 참가자(평균 연령 $20.1{\pm}4.0$, 남성 41%)를 대상으로 감성 유발 자극을 제시하고 동시에 생체신호(심전도, 혈류맥파, 피부전기활동)를 측정하였다. 또한 감성 유발 자극에 대한 심리 반응을 감성 평가 척도로 평가하였다. 측정된 생체신호에서 심박률(HR), NN 간격의 표준편차(SDNN), 혈류량(BVP), 맥파전달시간(PTT), 피부전도수준(SCL), 피부전도반응(SCR)을 추출하였다. 결과 분석을 위하여 감성 자극에 대한 각성도와 안정 상태와 감성 상태의 생체지표 반응을 활용하였다. 또한 감성 분류를 위하여 다중 신경망 기반의 감성 인식기를 활용하였다. 그 결과, 감성에 따른 생체지표 반응의 차이를 확인하였고, 이들 감성의 분류 성능은 각성도와 모든 생체지표 특징들을 조합하였을 때 정확도가 가장 높음(86.9%)을 확인하였다. 본 연구는 심리 및 생체지표 추출과 기계학습 기술의 적용을 통하여 부정 감성을 분류할 수 있음을 제안하며, 이는 인간의 감성을 탐지하는 감성 인식 기술을 확립하는데 기여할 것으로 예상한다.

Physiological and psychological effects of forest healing focused on plant fragrance therapy for maladjusted soldiers

  • Kim, Jihye;Sin, Changseob;Park, Jong-ok;Lee, Hyunchae;Kim, Jihye;Kim, Dohyeong;Kim, Sanghee
    • 인간식물환경학회지
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    • 제24권4호
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    • pp.429-439
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    • 2021
  • Background and objective: This study verified the physiological and psychological effects of plant fragrance therapy to analyze whether the therapy has a forest healing effect on maladjusted soldiers. Methods: This study was conducted from March 14 to May 31, 2020 according to the Green Camp curriculum for 2 weeks per recruit class. Thus, plant fragrance therapy was implemented twice each for three recruit classes. Each session of the program was carried out for 4 hours from 1 p.m. to 5 p.m. The venue was the garden within the camp and the forest nearby. Forest healing activities using plant fragrances were led by 1 forest education specialist and 1 assistant. The effects of plant fragrance therapy for maladjusted soldiers were analzed analyzed by quantifying physiological and psychological changes through measuring brain waves and stress levels before and after the therapy. Results: As a result of analyzing BRQ and SQ to determine the physiological and psychological healing effect of plant fragrance therapy, both the left and right brain showed higher BRQ and SQ after the therapy with statistical significance. This indicates that plant fragrance therapy on maladjusted soldiers helped positively stabilize their negative psychological and behavioral dispositions, and stabilization of brain waves lowered physical and mental stress and improved self-regulation and immunity. On the other hand, there was no significant difference in ATO. This is the result of analyzing the stress-coping mechanism. Troubleshooting (t = -2.702, df = 61, p = .009), emotional remission (t = -2.173, df = 61, p = .034), pursuit of help (t = -3.286), df = 61, p = .002), and wishful thinking (t = -3.714, df = 61, p < .001) showed statistically significant results. Conclusion: Applying plant fragrance therapy to maladjusted soldiers positively stabilized their negative psychological and behavioral dispositions and helped their self-regulation. Thus, plant fragrance therapy has psychological and physical forest healing effect on maladjusted soldiers.

THE ROLES OF ATP AND CALCIUM IN MORPHOLOGY CHANGES AND CYTOTOXICITY INDUCED BY BENZOQUINONE IN PLATELETS

  • Lee, Sun-Ku;Chung, Seung-Min;Lee, Moo-Yeol;Chung, Jin-Ho
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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    • pp.132-132
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    • 2001
  • To understand mechanism of benzoquinone-induced cytotoxicity, the roles of ATP and calcium in platelet toxicity and morphology changes was investigated. Using scanning electron microscopy, morphological changes to platelets following l,4-benzoquinone exposure consisted of membrane blebbing at 5 min which was significantly different from shape changes (pseudopod formation) observed in response to physiological agonists.(omitted)

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심근세포의 동기현상과 그 모델화 (The Syncronization Phenomena and Its Model of Myocardial Cells)

  • 박민용;제승정남
    • 대한의용생체공학회:의공학회지
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    • 제3권2호
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    • pp.101-104
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    • 1982
  • Even one embryonic myocardial cell exhibits a spontaneous, periodic beating phenomena. When these cells come in contact with each other, they beat synchronously with a certain period. In this paper, the mechanism of this phenomena is investigated, and the synchronization model is presented. The physiological experimental results are compared with the simulated results of the model.

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Action mechanism of estrogen potentials of Ginko biloba extracts and its major components in human breast cancer cell

  • Kim, Yun-Hee;Oh, Seung-Min;Lee, Hee-Sung;Chung, Kyu-Hyuck
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.166.2-167
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    • 2003
  • The important biological activities of estrogen were reproduction and physiological processes in a number of tissues, including liver, bone, brain, blood vessels, adipose tissue and so on. The regulation of estrogen level is important a prevention of estrogen-related disease. Ginkgo biloba extracts (GSE) are extracted from leaves of the Ginkgo biloba tree. GSE contains 24% phytoestrogen, which are kaempferol, quercetin, and isorhamnetin. (omitted)

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심장 부정맥 시 vortex breakup 현상에 대한 수치적 연구 (Computational analysis of vortex breakup in arrhythmias)

  • 심은보;권순성;최승윤
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.496-497
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    • 2008
  • In this study, we present the computational analysis of cardiac arrhythmias that is the major cause of human sudden cardiac death. First, electric excitation and condution in one dimensional cardiac tissue model is solved and the results on condution block are represented. In two dimensional model, vortex daynamics in cardiac tissue is analyzed to delineate the breakup phenomenon inducing ventricular fibrillation. We also simulated a three dimenional heart model to see the vortex breakup and explained the mechanism in physiological aspect.

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