• Title/Summary/Keyword: Action Potential

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Research and Anaysis of Wave Energy Characteristic for Wave Generation System

  • Oh Jin-Seok
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.4
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    • pp.520-526
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    • 2006
  • Wave Energy is a derivative of the solar energy input to the earth, which is accumulated on open water surfaces by the action of the winds Waves are disturbances in the water surface. This paper is interested primarily in progressive waves, which carry energy from one place to another Waves are irregular in size and frequency. Moreover the surface of the sea is one of the most hostile environments for engineering structures and materials. The idea of harnessing the tremendous power of the ocean's waves is not new. Hundreds of wave energy conversion techniques have been suggested over the last two centuries. Although many WECS (Wave Energy Conversion Systems) have been invented, only a few systems have been tested and evaluated. This paper describes the characteristic of WES (Wave Energy System) in terms of, devices, resource and potential, etc.. Finally, this paper provides a summary of general and specific conclusions and recommendations concerning WECS potential in Korea.

Potential Strategies for Prolonging the Usefulness of Bacillus thuringiensis in Engineered Rice

  • Bottrell, D.G.;Aguda, R.M.;Gould, F.L.;Theunis, W.;Demayo, C.G.;Magalit, V.F.
    • Korean journal of applied entomology
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    • v.31 no.3
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    • pp.247-255
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    • 1992
  • A laboratory bioassay that incorporates Bacillus thuringiensis (Bt) purified crystal protein toxins into an artificial diet has identified three toxins, CryIA(b), CryIA(c), and CryIIA, to by effective against the yellow stemborer, Scirpophaga incertulas(Walker). Research is aimed at engineering rice that incorporates genes of one of or more of these toxins so as to mimic the insecticidal action of the insect to Bt. The paper discusses potential strategies for slowing the rate of adaptation that include the use of multiple Bt toxins, promoters that express the toxins only in specific plant tissues at specific times, and mixing transgenic and non-transgenic plants.

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Sucrose-Gap Apparatus를 이용한 말초신경계의 Opiate수용체 검색법

  • ;George B. Frank
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1992.05a
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    • pp.40-40
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    • 1992
  • opiate receptor들의 중추신경계에서의 분포 및 작용에 관한 실험물은 널리 알려져 있어 그 웅용 방법도 많이 있으나, 말초에 있는 opiate receptor의 존재 및 약물작용을 관찰하는 실험은 별로 알려진 것은 없다. 저자는 214mM의 sucrose 용역을 이용하여 전기적 자극에 따른 말초신경 및 말초조직(근육)에서의 opiate receptor애 대한 작용을 관찰하였다. 실험은 3분류의 약물을 이용하였다. 1) Pure agonists: morphine, meperidine, methadone, 2) Agonist-antagonist: buprenorphine 3) Pure antagonist: naloxone 위의 약물들을 이용하여 excitable cell membrane(좌골신경 및 근육)에서 일어나는 potential의 변화를 관찰하여 다음과 같은 결과를 얻었다. a. pure agonists들은 좌골신경 및 근육절편에서 action potentials을 의의있게 억제시켰으며 meperidine이 가장 강한 작용을 보였다. b. 이들의 작용은 naloxone 투여로 억제되었다. c. Agonist-antagonist인 buprenorphine은 투여용량 및 동시 투여한 pure agonist의 종류에 따라 biphasic pattern을 나타내었다. d. opiates 작용기전 및 약물작용장소를 알고자 두 종류, 즉 single 및 double technique을 사용하여 비교하였다.

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Cancer Chemoprevention by Dietary Proanthocyanidins

  • Jo, Jeong-Youn;Lee, Chang-Yong
    • Food Science and Biotechnology
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    • v.16 no.4
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    • pp.501-508
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    • 2007
  • Proanthocyanidins (PACs), also named condensed tannins, are polymers of flavan-3-ols such as (+ )-(gallo)catechin and (-)-epi(gallo)catechin. A proper analysis of the PACs, with difficult challenges due to their complex structures, is crucial in studies of cancer chemoprevention. Cancer is a leading cause of mortality around the world. Many experimental studies have shown that dietary PACs are potential chemopreventive agents that block or suppress against multistage carcinogenesis in both in vitro and in vivo models. Cancer chemoprevention by dietary PACs has been shown effective through different mechanisms of action such as antioxidant, apoptosis-inducing, and enzyme inhibitory activities. Good sources of dietary PACs are nuts, fruits, beans, chocolate, fruit juice, red wine, and green tea. The chemopreventive potential of dietary PACs should be considered together with their bioavailability in humans. The safety issues regarding carcinogenesis and gastrointestinal disorder are also reviewed.

Reproducibility of Statistical Motor Unit Number Estimate in Amyotrophic Lateral Sclerosis: Comparisons between Size-and Number-Weighted Modifications (근위축성 측삭 경화증에서의 Statistical Motor Unit Number Estimate 재연성: Size-and Number-Weighted Modifications간의 비교)

  • Kwon, Oh Yun;Lee, Kwang-Woo
    • Annals of Clinical Neurophysiology
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    • v.5 no.1
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    • pp.27-33
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    • 2003
  • Background: Motor unit number estimation (MUNE) can directly assess motor neuron populations in muscle and quantify the degree of physiologic and/or pathologic motor neuron degeneration. A high degree of reproducibility and reliability is required from a good quantitative tool. MUNE, in various ways, is being increasingly applied clinically and statistical MUNE has several advantages over alternative techniques. Nevertheless, the optimal method of applying statistical MUNE to improve reproducibility has not been established. Methods: We performed statistical MUNE by selecting the most compensated compound muscle action potential (CMAP) area as a test area and modified the results obtained by weighted mean surface-recorded motor unit potential (SMUP). Results: MUNE measures in amyotrophic lateral sclerosis (ALS) patients showed better reproducibility with sizeweighted modification. Conclusions: We suggest size-weighted MUNE testing of "neurogenically compensated"CMAP areas present an optimal method for statistical MUNE in ALS patients.

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Electrostatic Properties of N-Acetyl-Cysteine-Coated Gold Surfaces Interacting with TiO2 Surfaces

  • Park, Jin-Won
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.902-906
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    • 2009
  • It is found that that the coating N-acetyl cysteine (NAC) on gold surfaces may be used to design the distribution of either gold particle adsorbed to the $TiO_2$ surface or vice versa by adjusting the electrostatic interactions. In this study, we investigated electrostatic properties of the NAC-coated-gold surface and the $TiO_2$ surface. The surface forces between the surfaces were measured as a function of the salt concentration and pH value using the AFM. By applying the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to the surface forces, the surface potential and charge density of the surfaces were quantitatively acquired for each salt concentration and each pH value. The surface potential and charge density dependence on the salt concentration was explained with the law of mass action, and the pH dependence was with the ionizable groups on the surface.

Cancer Chemopreventive Potential of Procyanidin

  • Lee, Yongkyu
    • Toxicological Research
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    • v.33 no.4
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    • pp.273-282
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    • 2017
  • Chemoprevention entails the use of synthetic agents or naturally occurring dietary phytochemicals to prevent cancer development and progression. One promising chemopreventive agent, procyanidin, is a naturally occurring polyphenol that exhibits beneficial health effects including anti-inflammatory, antiproliferative, and antitumor activities. Currently, many preclinical reports suggest procyanidin as a promising lead compound for cancer prevention and treatment. As a potential anticancer agent, procyanidin has been shown to inhibit the proliferation of various cancer cells in "in vitro and in vivo". Procyanidin has numerous targets, many of which are components of intracellular signaling pathways, including proinflammatory mediators, regulators of cell survival and apoptosis, and angiogenic and metastatic mediators, and modulates a set of upstream kinases, transcription factors, and their regulators. Although remarkable progress characterizing the molecular mechanisms and targets underlying the anticancer properties of procyanidin has been made in the past decade, the chemopreventive targets or biomarkers of procyanidin action have not been completely elucidated. This review focuses on the apoptosis and tumor inhibitory effects of procyanidin with respect to its bioavailability.

Complete genome sequence of Bacillus coagulans CACC834 isolated from canine

  • Kim, Jung-Ae;Kim, Dae-Hyuk;Kim, Yangseon
    • Journal of Animal Science and Technology
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    • v.63 no.6
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    • pp.1464-1467
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    • 2021
  • Bacillus coagulans CACC 834 was isolated from canine feces, and its potential probiotic properties were characterized by functional genome analysis. Whole-genome sequencing of B. coagulans CACC 834 was performed using the PacBio RSII platforms. The complete genome assembly consisted of one circular chromosome (3.1 Mb) with guanine (G) + cytosine (C) content of 47.1%. Annotation revealed 3,181 protein-coding sequences (CDSs), 30 rRNAs, and 83 tRNAs. Gene associated 11% of the genes were involved in replication, recombination, and repair. We also annotated various stress-related, acid resistance, bile salt resistance and adhesion-related domains in this strain, which likely provide support in exerting probiotic action by survival under gastrointestinal tract. These results add to our comprehensive understanding of B. coagulans and suggest potential mammal-related industrial applications.

Hydrodynamic characteristics of a fixed semi-submersible platform interacting with incident waves by fully nonlinear method

  • Zhang, Zi-Lin;Yuan, Hong-Tao;Sun, Shi-Li;Ren, Hui-Long
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.526-544
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    • 2021
  • Based on the potential flow theory, a fully nonlinear numerical procedure is developed with boundary element method to analyze the interaction between a fixed semi-submersible platform and incident waves in open water. The incident wave is separated from the scattered wave under fully nonlinear boundary conditions. The mixed Euler-Lagrangian method is used to capture the position of the disturbed wave surface in local coordinate systems. The wave forces exerted on an inverted conical frustum are used to ensure the accuracy of the present method and good agreements with published results are obtained. The hydrodynamic characteristics of the semi-submersible platform interacting with regular waves are analyzed. Pressure distribution with time and space, tension and compression of the platform under wave action are investigated. 3D behaviors of wave run-ups are predicted. Strong nonlinear phenomena such as wave upwelling and wave interference are observed and analyzed.

An analysis of pinch strength and EMG parameters for CTS group

  • Lee, H.I.;Lee, D.C.;Lee, S.D.
    • Journal of the Ergonomics Society of Korea
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    • v.15 no.2
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    • pp.139-147
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    • 1996
  • It is known fact that the CTS patients have lower pinch strength than the normal people. And we can assume that the sensory nerve action potential(SNAP) and the nerve conduction velocity(NCV) of the CTS group are lower or slower than the normal subjects. This paper analysed the grip strength and performed EMG experiment for the group Norm, G1 and G2. The results are as follows: 1) CTS patients have lower pinch strength than normal people. 2) There was no significant difference on SNAP between the CTS group and the normal group. 3) There was significant difference on NCV among Norm, G1, and G2 group. Especially, significant level was higher in the evening after the continuous use of wrist.

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