• 제목/요약/키워드: Immune mechanism

검색결과 651건 처리시간 0.024초

Immune Algorithm Based Active PID Control for Structure Systems

  • Lee, Young-Jin;Cho, Hyun-Cheol;Lee, Kwon-Soon
    • Journal of Mechanical Science and Technology
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    • 제20권11호
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    • pp.1823-1833
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    • 2006
  • An immune algorithm is a kind of evolutional computation strategies, which is developed in the basis of a real immune mechanism in the human body. Recently, scientific or engineering applications using this scheme are remarkably increased due to its significant ability in terms of adaptation and robustness for external disturbances. Particularly, this algorithm is efficient to search optimal parameters against complicated dynamic systems with uncertainty and perturbation. In this paper, we investigate an immune algorithm embedded Proportional Integral Derivate (called I-PID) control, in which an optimal parameter vector of the controller is determined offline by using a cell-mediated immune response of the immunized mechanism. For evaluation, we apply the proposed control to mitigation of vibrations for nonlinear structural systems, cased by external environment load such as winds and earthquakes. Comparing to traditional controls under same simulation scenarios, we demonstrate the innovation control is superior especially in robustness aspect.

두경부암에서 면역회피 기전과 면역항암제 치료 (Immune Evasion Mechanism as a Guide for Immunotherapy in Head and Neck Cancer)

  • 장현
    • 대한두경부종양학회지
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    • 제33권1호
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    • pp.1-5
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    • 2017
  • 두경부 편평상피세포암은 전세계적으로 6번째로 흔하며 예후가 불량한 암종이다. 면역 감시는 두경부암의 발생과 진행을 억제하는 중요한 기전으로 알려져 있다. 두경부암세포는 면역 감시를 T세포의 관용을 유도하거나 체크포인트를 통한 T세포 기능을 억제하는 등의 방법으로 회피할 수 있다. 한편 진행성 두경부암 임상연구에서 체크포인트 억제제는 명확한 항종양효과를 입증하였다. 이처럼 면역항암제가 중요한 암치료 방법으로 떠오르는 이때에 본 종설은 두경부암의 면회회피 기전 및 임상적용근거에 대한 최근 지식을 정리하였다.

면역 피드백 메카니즘과 경사감소학습에 기초한 비선형 적응 PID 제어기 설계 (Nonlinear Adaptive PID Controller Desist based on an Immune Feedback Mechanism and a Gradient Descent Learning)

  • 박진현;최영규
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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    • pp.113-117
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    • 2002
  • PID controllers, which have been widely used in industry, have a simple structure and robustness to modeling error. But it is difficult to have uniformly good control performance in system parameters variation or different velocity command. In this paper, we propose a nonlinear adaptive PR controller based on an Immune feedback mechanism and a gradient descent teaming. This algorithm has a simple structure and robustness to system parameters variation. To verify performances of the proposed nonlinear adaptive PID controller, the speed control of nonlinear DC motor Is peformed. The simulation results show that the proposed control systems are effective in tracking a command velocity under system parameters variation

Beyond Viral Interferon Regulatory Factors: Immune Evasion Strategies

  • Myoung, Jinjong;Lee, Shin-Ae;Lee, Hye-Ra
    • Journal of Microbiology and Biotechnology
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    • 제29권12호
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    • pp.1873-1881
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    • 2019
  • The innate immune response serves as a first-line-of-defense mechanism for a host against viral infection. Viruses must therefore subvert this anti-viral response in order to establish an efficient life cycle. In line with this fact, Kaposi's sarcoma-associated herpesvirus (KSHV) encodes numerous genes that function as immunomodulatory proteins to antagonize the host immune system. One such mechanism through which KSHV evades the host immunity is by encoding a viral homolog of cellular interferon (IFN) regulatory factors (IRFs), known as vIRFs. Herein, we summarize recent advances in the study of the immunomodulatory strategies of KSHV vIRFs and their effects on KSHV-associated pathogenesis.

Formalin 처리(處理) 면역원(免疫原)에 대한 가토(家兎)의 혈액세포상(血液細胞像)에 관한 연구 (Hematological Studies in Reference to Immune Enhancement Mechanism of Formalin Applied to Formalin Inactivated Anthrax Vaccines in Rabbits)

  • 전윤성;최희인
    • 대한수의학회지
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    • 제16권1호
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    • pp.45-51
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    • 1976
  • Hematological studies were conducted in reference to the immune enhancing mechanism of formalin applied to, as an inactivating agent, a formalin inactivaed anthrax vaccines in rabbits. Rabbits were inoculated two types of formalinized anthrax immunogens namely capsular and spore vaccines in addition of formalin saline as a control. From immune rabbits, peripheral blood was collected and subjected to count a total erythrocytes, leukocytes, and pyroninophilic lymphocytes. The experimental results were summarized as followings. At a level of 0.5M 0.5ml formalin with or without the addition to vaccine, a total leukocytes count was increased. Due to the increased lymphocytes, the ratio of neutrophil and lymphocyte was lowered within 4 to 12 hours of the postinoculation. Formalin saline, anthrax spore vaccine and capsular vaccine, without group difference, caused an increased level of pyroninophilic lymphocytes in peripheral blood. Throughout the studies, a possible role of immune enhancement by formlin was disscused and suggested.

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식물체의 면역반응 기작 (Molecular Mechanism of Plant Immune Response)

  • 권택민;남재성
    • Journal of Plant Biotechnology
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    • 제32권2호
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    • pp.73-83
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    • 2005
  • Disease resistance in plants is often controlled by gene-for-gene mechanism in which avirulence (avr) gene products encoding by pathogens are specifically recognized, either directly or indirectly by plant disease resistance (R) gene products and sequential signal transduction pathways activating defense responses are rapidly triggered. As a results, not only exhibit a resistance against invading pathogens but also plants maintain the systemic acquired resistance (SAR) to various other pathogens. This molecular interaction between pathogen and plant is commonly compared to innate immune system of animal. Recent studies arising from molecular characterization of a number of R genes from various plant species that confer resistance to different pathogens and corresponding avr genes from various pathogens resulted in the accumulation of a wealth of knowledge on molecular mechanism of gene-for-gene interaction. Furthermore, new technologies of genomics and proteomics make it possible to monitor the genome-wide gene regulation and protein modification during activation of disease resistance, expanding our ability to understand the plant immune response and develop new crops resistant to biotic stress.

A Feasibility Study on Application of Immune Network for Intelligent Controller of a Multivariable System

  • Kim, Dong-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.115.5-115
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    • 2001
  • This paper suggests that the immune algorithm can effectively be used in tuning of a multivariable system. Then artificial immune network always has a new paraller decentralized processing mechanism for various situations, since antibodies communication to each other among different species of antibodies/B-cells through the simulation and suppression chains among antibodies that form a large-scaled network. In addition to that, the structure of the network is not fixed, but varies continuously. That is, the artificial immune network flexibly self-organizes according to dynamic changes of external environment (meta-dynamics function). However, up to the present time, models based on the conventional crisp approach ...

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면역반응 알고리즘을 이용한 구조물의 진동제어 (A Vibration Control of the Strcture using Immune Response Algorithm)

  • 이영진;이권순
    • 한국항만학회지
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    • 제13권2호
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    • pp.389-398
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    • 1999
  • In the biological immunity, the immune system of organisms regulates the antibody and T-cells to protect the attack from the foreign materials which are virus, germ cell, and other antigens, and supports their stable state. It has similar characteristics that has the adaptation and robustness to overcome disturbances and to control the plant of engineering application. In this paper, we build a model of the T-cell regulated immune response mechanism. We have also designed an immune response controller(IRC) focusing on the T-cell regulated immune response of the biological immune system that include both a help part to control the response and a suppress part to adjust system stabilization effect. We show some computer simulation to control the vibration of building structure system with strong wind forces excitation also demonstrate the efficiency of the proposed controller for applying a practical system even with existing nonlinear terms.

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Mycobacterium tuberculosis Derived Epitope Peptide Specific CD8+T Cell Responses in Tuberculous Pleurisy

  • ;;;;;조상래;조성애
    • 대한의생명과학회지
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    • 제13권4호
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    • pp.325-332
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    • 2007
  • Cell-mediated immune response (CMI) is a major immune protective mechanism against tuberculosis (TB) infection. Among several components involved in CMI, recent studies suggest that CD8+ T cells are important in controlling TB infection. In our previous report, we defined four Mycobacterium tuberculosis (MTB) derived epiotpe peptides specific for HLA-A*0201-restricted CD8+ T cells. These four peptides are $PstAl_{75-83}$, $ThyA_{30-38}$, $RpoB_{127-135}$ and $85B_{15-23}$. In this study, these epitope peptides specific CD8+ T cell responses in tuberculous pleurisy were investigated using ex vivo $IFN-\gamma$ elispot assay and intracellular $IFN-\gamma$ staining method. As a result, we observed these epitope peptide specific CD8+ T cell responses are induced in all three patients with tuberculous pleurisy suggesting that CD8+ T cells are involved in protective immune mechanism against MTB infection in tuberculous pleurisy. However, the CMI to mitogens and MTB antigens from pleural fluids of patients with tuberculous pleurisy does not seem to correlate with that from peripheral blood, although the sample size is too small to make any conclusion. In sum, the MHC I restricted CD8+ T cell responses seem to be induced efficiently in the pleural fluids, at the site of TB infection, in which the CMI is actively induced. In addition, these experiments suggest that MHC I restricted CD8+ T cell mediated immune responses are also involved in protective mechanism against MTB infection in extra-pulmonary TB.

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Molecular Perspectives of SARS-CoV-2: Pathology, Immune Evasion, and Therapeutic Interventions

  • Shah, Masaud;Woo, Hyun Goo
    • Molecules and Cells
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    • 제44권6호
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    • pp.408-421
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    • 2021
  • The outbreak of coronavirus disease 2019 (COVID-19) has not only affected human health but also diverted the focus of research and derailed the world economy over the past year. Recently, vaccination against COVID-19 has begun, but further studies on effective therapeutic agents are still needed. The severity of COVID-19 is attributable to several factors such as the dysfunctional host immune response manifested by uncontrolled viral replication, type I interferon suppression, and release of impaired cytokines by the infected resident and recruited cells. Due to the evolving pathophysiology and direct involvement of the host immune system in COVID-19, the use of immune-modulating drugs is still challenging. For the use of immune-modulating drugs in severe COVID-19, it is important to balance the fight between the aggravated immune system and suppression of immune defense against the virus that causes secondary infection. In addition, the interplaying events that occur during virus-host interactions, such as activation of the host immune system, immune evasion mechanism of the virus, and manifestation of different stages of COVID-19, are disjunctive and require thorough streamlining. This review provides an update on the immunotherapeutic interventions implemented to combat COVID-19 along with the understanding of molecular aspects of the immune evasion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may provide opportunities to develop more effective and promising therapeutics.