• Title/Summary/Keyword: Mechanism of action

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Cell Ploidy and Repair Ability Determine the Radioprotective Effects of Cysteamine in Yeast Cells of Various Species and Genotypes

  • Vladislav G. Petin;Kim, Jin-Kyu
    • Korean Journal of Environmental Biology
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    • v.20 no.1
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    • pp.35-39
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    • 2002
  • The significance of cell ploidy and repair ability for the radioprotective efficiency of cysteamine was studied in DNA repair - proficient and repair - deficient yeast cells irradiated $^{60}C0\;\gamma-rays.$ Results have been obtained for the cell survival of two groups of yeasts-diplont and haplont cells, both in haploid and diploid states. For diploid Saccharomyces cerevisiae yeast cells, the correlation between the radio-protective action of cysteamine and the cell repair capacity was demonstrated. Such a correlation was not clearly expressed for haploid yeast cells. In addition, evidence was obtained indicating that the degree of the radioprotective action was independent of the number of chromosome sets in haplont yeast Pichia guilliermondii cells and in some radiosensitive mutants defective in the diploid-specific recovery. It is concluded on this basis that the radioprotective action may involve the cellular recovery process, which may be mediated by a recombination-like mechanism, for which the diploid state is required. The results obtained clearly show that the radioprotective effect was dependent on DNA repair status and indicate that the mechanism of the radioprotective action may be realized on the level of primary radiation damage production as well as on the level of postradiation recovery from potentially lethal radiation damage.

A study on the relationship between the movement of animation and heritage of modern mechanism (애니메이션의 움직임과 근대 기계론 전통의 상관관계 연구)

  • Kim, Takhoon;Han, Tae-Sik
    • Cartoon and Animation Studies
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    • s.30
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    • pp.27-57
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    • 2013
  • Animation which appeared with films in the late 19th century was a medium which came on obtaining nourishment from art historical style of modernism. However, the relation establishment between animation and modernism has been focused mainly on animation shapes, namely painted images. This sprang from explaining the relationship between animation and paintings, and for this reason, discussions of movements in animation were understood in tradition of chromophotograph of Muybridge and Jules Marey, or some characteristics owned by the live-action film. However, movements of animation were essentially different from the indexical sign of films or photogram, and objects of reproduction were different between them. Movements reproduced by animation are not ordinary movements, but expressions of or compressed movements and considerably systematic movements. As a result, these movements are far from reproduction of live-action film photogram. Rather, the logic of movements reproduced by animation comes near to controlling their motion scopes, time, distance etc. after dividing each part of the body. This is concluded in a standpoint of modern mechanism which is represented by Descartes and La Mettrie who tried to understand human body as a exchangeable machine. Design of modern mechanism ranging from modern society to industrial society and the age of modernism came to lead to analysis of physical motions of modern industrial society called composition of efficient movements understanding them as the law of nature rather than movements as nature. In the late 19th century, Taylor, F. W. and Gilbreth, Frank Bunker's studies of workers' working hours and 'motion study' were a way of constituting the frame of machine-human, which indicates that tradition of modern mechanism affected the entire modernism passing through industrial society. Further, we can see that motion studies conducted by them have almost similar characteristics to action analysis to study animation later in the name of 'timing'.

The Action Mechanism of Diazepam on the Contractility of Canine Trachealis Muscle (개의 기관근 수축성에 대한 Diazepam의 작용기전)

  • 권오철;최은미;최형철;김용대;하정희;서장수;이광윤
    • Korean Journal of Bronchoesophagology
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    • v.4 no.1
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    • pp.64-72
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    • 1998
  • This study aimed at observing the effect of diazepam on the contractility of trachealis muscle isolated from canine trachea, possible involvement of central or peripheral type benzodiazepine receptor, and the calcium related mechanism of action of diazepam. Trachealis muscle strips of 15 mm long were suspended in an isolated organ bath containing 1 ml of physiologic salt solution maintained at $37^{\circ}C$, and aerated with 95% $O_2$ /5% $CO_2$. Isometric myography was performed. Diazepam reduced the basal tone concentration dependently, and this inhibitory action was not affected by neither flumazenil, a central benzodiazepine receptor antagonist, nor PK11195, a peripheral benzodiazepine receptor antagonist. Pretreatment with diazepam showed the inhibitory effect on the concentration-response curves to agonists such as bethanechol, 5-hydroxytryptamine and histamine. Diazepam also caused concentration-related inhibition of contraction with potassium chloride 30 mM. The effect of diazepam on the basal tone and potassium chloride-induced contraction with calcium channel blockers were compared. Similar results were obtained in canine trachealis with verapamil, nifedipine and diltiazem. These results suggest that diazepam relax an airway muscle not via specific receptors but by a similar action as calcium channel blockers in canine trachealis muscle.

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STAGCN-based Human Action Recognition System for Immersive Large-Scale Signage Content (몰입형 대형 사이니지 콘텐츠를 위한 STAGCN 기반 인간 행동 인식 시스템)

  • Jeongho Kim;Byungsun Hwang;Jinwook Kim;Joonho Seon;Young Ghyu Sun;Jin Young Kim
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.6
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    • pp.89-95
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    • 2023
  • In recent decades, human action recognition (HAR) has demonstrated potential applications in sports analysis, human-robot interaction, and large-scale signage content. In this paper, spatial temporal attention graph convolutional network (STAGCN)-based HAR system is proposed. Spatioal-temmporal features of skeleton sequences are assigned different weights by STAGCN, enabling the consideration of key joints and viewpoints. From simulation results, it has been shown that the performance of the proposed model can be improved in terms of classification accuracy in the NTU RGB+D dataset.

Snake Robot Motion Scheme Using Image and Voice (감각 정보를 이용한 뱀 로봇의 행동구현)

  • 강준영;김성주;조현찬;전홍태
    • Proceedings of the IEEK Conference
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    • 2002.06c
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    • pp.127-130
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    • 2002
  • Human's brain action can divide by recognition and intelligence. recognition is sensing voice, image and smell and Intelligence is logical judgment, inference, decision. To this concept, Define function of cerebral cortex, and apply the result. Current expert system is lack, that reasoning by cerebral cortex and thalamus, hoppocampal and so on. In this paper, With human's brain action, wish to embody human's action artificially Embody brain mechanism using Modular Neural Network, Applied this result to snake robot.

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Influence of Phellodendri Cortex Methanol Extract on the Responses of the Blood Pressure in the Rabbits and Cats (황백(黃柏) Methanol Extract의 가토(家兎) 및 가묘(家猫)의 혈압반응(血壓反應)에 미치는 영향(影響))

  • Lim, Dong-Yoon
    • Journal of Pharmaceutical Investigation
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    • v.9 no.3
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    • pp.27-38
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    • 1979
  • This study was attempted to investigate the pharmacological action, especially depressor action of Phellodendri cortex and to elucidate the mechanism of its action, making use of Phellodendri cortex methanol extract (PCME) because its hypotensive action is not clear. Influence of PCME on the blood pressure of the rabbits and cats were observed in this study. PCME, when given intravenously in the rabbits and cats, elicited the hypotensive action, but intraventricular PCME in the rabbits did not show depressor action. Accumulation and tachyphylaxis by PCME administered into the ear-vein of the rabbits were not shown. Depressor effect of PCME in the rabbits was attenuated significantly by pretreatment with phentolamine, guanethidine, chorisondamine and atropine, but not by propranolol, diphenhydramine, cyproheptadine and vagotomization. The pressor activity of angiotensin was unimpaired after injection of maximal hypotensive doses (100mg/kg) of PCME, but the pressor activity of norepinephrine and carotid occlusion was abolished markedly. In addition, PCME given into jugular vein of the cats weakened norepinephrine pressor responses and caused the reversal of epinephrine pressor responses. These results suggest that the hypotensive action of PCME may be due to dual mechanisms by interference with peripheral sympathetic function, alpha adrenoceptor blocking action, and peripheral parasympathomimetics action, muscarinic action.

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The Mechanism of Load Resistance and Deformability of Reinforced Concrete Coupling Beams (철근 콘크리트 연결보의 하중 전달 기구와 변형 능력)

  • Hong, Sung-Gul;Jang, Sang-Ki
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.3 s.49
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    • pp.113-123
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    • 2006
  • An experimental investigation on the behavior of reinforced concrete coupling beams is presented. The test variables are the span-to-depth ratio, the ratio of flexural reinforcements and the ratio of shear rebars. The distribution of arch action and truss action which compose the mechanism of shear resistance is discussed. The increase of plastic deformation after yielding transforms the shear transfer by arch action into by truss action. This study proposes the deformation model for reinforced concrete coupling beams considering the bond slip of flexural reinforcement. The strain distribution model of shear reinforcements and flexural reinforcements based on test results is presented. The yielding of flexural reinforcements determines yielding states and the ultimate states of reinforced concrete coupling beam are defined as the ultimate compressive strain of struts and the degradation of compressive strength due to principal tensile strain of struts. The flexural-shear failure mechanism determines the ultimate state of RC coupling beams. It is expected that this model can be applied to displacement-based design methods.

Analgesic Action Mechanism of DA-5018, a New Capsaicin Derivative : Relationship to Opiate :Receptors and Prostanoids (새로운 캅사이신 유도체 DA-5018의 진통활성 기전연구: Opiate 수용체 및 :Prostanoid와의 상관성)

  • 손미원;손문호;배은주;김순희;김원배;양중의
    • Biomolecules & Therapeutics
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    • v.5 no.1
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    • pp.87-93
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    • 1997
  • DA-5018, a new capsaicin derivative, showed potent analgesic effect comparable to that of morphine in various experimental acute pain models. in this study, whether the analgesic mechanism of DA-5018 is related to opiate receptors or prostanoids was investigated. The affinity of DA-5018 for opiate receptor was determined by receptor binding assay. The Ki values of DA-5018 for nonspecific and specific $\mu$, $textsc{k}$, $\delta$-opiate receptor was 299$\pm$8.88, 735$\pm$215, 2930$\pm$ 163, 1550$\pm$813 nM, respectively and DA-5018 exhibited lower affinity than morphine. DA-5018 (10-"~3$\times$10-′M) inhibited electrically-evoked contractions of the guinea ply ileum and rat vas deferens, and these inhibition was not antagonized by naloxone(10 nM), an opiate receptor antagonist. Antagonism of analgesic effect of 7A-5018 by naloxone was examined by tail pinch test. Analgesic action of DA-5018(0.1 ~2 mg/kg, 5.c.) was not antagonized by naloxone(1 mg/rg, i.p.). These results indicate that pharmacological action of DA-5018 is not related with opiate receptor. Cyclooxygenase and 5-lipoxygenase activities in rat peritoneal neutrophil treated with A23187 and arachidonic acid were measured by radioimmunoassay. DA-5018 stimulated the cyclooxygenase activity and the concentration show-ing the two fold increase of activity was 124$\mu$M. DA-5018 slightly inhibited 5-lipoxygenase activity and these results together indicate that analgesic action of 3A-5018 is not mediated through inhibition of cyclooxy genase or lipoxygenase. These results suggest that the analgesic effect of DA-5018 is not due to blocking opiate receptor or to inhibiting the synthesis of prostanoids in the arachidonic acid metabolism pathway.

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Studies on the Diuretic Action of Oryeongsan and Kami-Oryeongsan (오령산(五笭散) 및 가미오령산(加味五笭散)이 가토이뇨작용(家兎利尿作用)에 미치는 영향(影響))

  • Lee, Sang-In
    • Korean Journal of Pharmacognosy
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    • v.12 no.1
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    • pp.31-43
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    • 1981
  • In order to determine the effect of Oryeongsan reputed to have diuretic action since Han Dynasty and possible synergetic action of Dianthi Semen, Polygonum avicularis Herba, Kochiae Fructus and Akebiae Lignum, herbs with similar reputation, when added to the above prescription, their decoction powders were solved into distilled water and injected into rabbits through the ear vein. Upon the treatment, the excretion of sodium, potassium and chloride ion together with urine volume was kinetically determined. At the same time the clearance of plasma creatinine and sodium ion was determined and the following results were obtained. Every experimental group demonstrated diuretic action, though feable, of relatively long duration. The diuretic mechanism in the case of Oryeongsan made up by mixing the seperate extracts of individual components and Oryeongsan(A) plus Dianthi Semen was found to be inhibitory effect of renal tubular reabsorption in contrast to the case of Oryeongsan(A) plus Polygonum avicularis Herba, Kochiae Fructus or Akebiae Lignum in which case the diuretic mechanism was found to be glomerular vascular dilatation. The urinary excretion of potassium ion was increased in the case of Oryeongsan(A) plus Dianthi Semen, Kochiae Fructus of Akebiae Lignum whereas in the other cases no similar change was registered. The diuretic action was most remarkable in the case of Oryeongsan(A) plus Polygonum avicularis Herba followed by Oryeongsan(A) plus Kochiae Fructus, Oryeongsan(A) plus Dianthi Semen, extract mixture of individual component of Oryeongsan, Oryeongsan(A) and Oryeongsan(A) plus Akebiae Lignum decreasing order. The duration of diuretic action was found to be 90 minutes in the case of Oryeongsan and mixture of individual component of Oryeongsan, and 60 minutes in the case of Oryeongsan(A) plus Dianthi Semen, Kochiae Fructus or Akebiae Lignum in contrast to the case of Oryeongsan(A) plus Polygonum avicularis Herba which lasted up to 120 minutes.

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Pharmacological Action of Machilus Thunbergii Siebold Zuccarini (한국산 생약제들의 혈압강하작용에 대한 연구 II. 한국산 후박수피의 혈압강하 작용)

  • Cho B.H.;Kim I.H.;Lee S.B.;Cho K.C.;Lee J.H.
    • The Korean Journal of Pharmacology
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    • v.15 no.1_2 s.25
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    • pp.45-56
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    • 1979
  • With a view to searching after a new antihypertensive or hypotensive agents in the botanical crude plants, authors intended to reevaluate several natural products caltivated in Korea. This experiment was undertaken to compare pharmacogical actions of Machilus thunbergii Siebold et Zuccarini with those of Magnolia obovata Thunberg in anesthetized rats and in normal mice. Machilus thunbergii Sieb. et Zucc., a tree belonging to the Lauraceae family, is caltivated at Ull-ung Do, and their cortecies have been used as folk medicine mingled with those of Magnolia obovata Thunberg. These two cortecies have teen also applied in chinese medicine, it was advocated that these cortecies exerted good therapeutic effects on gastritis, convulsive abdominal pain, nausea, vomiting and urinary tract disorders. Therefore, we intended to determine the pharmacological action of two palnt of different family each other, especially their effects on blood pressure and heart rate, and also their mechanism of action were observed. We studied their action with extracts of hexane(MTHE), ether(MTEE), methanol(MTME) and water(MTWE) from Machilus thunhergii Sieb. et Zucc., and also fractionations of methanol(MOME), chloroform(MOCE) and water(MOWE) from Mapolia obovata Thunberg. The results of this experiment were as follows; 1) MTME, when intravenously administered to rats, elicited the significant hypotensive responses dependent on the administered dosage. 2) MOWE was also exhibited the hypotensive effect dependent on the treated dose. 3) Depressor effect of MTME was blocked by pretreatment with hexamethonium. 4) The hypotensive response of MOWE was blocked by pretreatment with hexamethonium or hrdralazine. 5) HTME and MOWE were also observed the anticonvulsive effect and sedative effect. These results suggested that MTME may induce the hypotensive response via central sympathetic effect, but the site of action in brain are not clarified, and the hypotensive effect of MOWE may be due to dual mechanism of central sympathetic action and direct vasodilation of blood vessel.

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