• Title/Summary/Keyword: agent model

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멀티미디어 서비스의 환경변화 및 COSMOS 멀티미디어 운영체제

  • 송동호;임영환
    • Information and Communications Magazine
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    • v.11 no.6
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    • pp.37-54
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    • 1994
  • Technical innovation on multimedia data processing brings us new multimedia services. Multimedia services are classified into five groups : TVs, computers, telecommunications, periperals, and softwares. This paper surveys on the services in various aspects and, in particular, computer areas are discussed in detail. To provide the services, major subsystems such as highspeed networks, operating systems, intelligent agent based user interfaces are discussed. In particular, multimedia operating systems are the most actively investigating research area as an infrastructure of multimedia computer systems to provide integrated multimedia services. So, the trends of new multimedia operating systems are analyzed and COSMOS (Collaborative Object Sharing for Multimedia Operating System) multimedia group presentation is discussed. The characteristics, model and abstract data structure of COSMOS is described. The performance analysis of 3 person conference system using audio, video and shared graphic editor on COSMOS shows that taking integrated multimedia operating system approach leads changing of new multimedia service environments.

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Current Application of Embryo Cryopreservation for Farm Animals (가축 수정란 동결보존의 최근 이용방법)

  • 석호봉
    • Journal of Embryo Transfer
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    • v.4 no.1
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    • pp.1-13
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    • 1989
  • This paper reviews the most important steps that have generated consistent progress in principles and developmental progress of embryo cryopreservation, and also study on freezing procedure and its application by conventional method and current improved method for freezing procedure and its appilcation of embryo cryopreservation in farm animals. Four were of particular interest: 1.The transport of water across the ccli membrane (zona pellucida) during freezing and thawing accordinglyplays a role in determing whether the celi survives. This movement of water is controlied mainly by extracellular phase changes and by the nature and concentration of any cryoprotective agent present. Therates of cooling, freezing and warming, and the intervals over which they are applied are further decisi've factors in determining whether a cryopreservation procedure allows survival after thawing. 2.The first successful deep freezing experiments with sheep morula and blastocysts during the seventies were based on the early procedures used for mouse embryos.Current research during the eighties is developed with the aim of simplifying and improving current procedures such as one-step dilution and rapid or ultra-rapid cooling by using the model of laboratory animals. 3.The conventional method for the embryo cryopreservation is described. An alternative to this method which may result in high survival and also in reducing of the freezing and thawing time is done by combing a permeable cryoprotectant such as glycerol, DMSO or propanediol and a non-permeable compound such as sucrose, trehalose, raffinose or lactose. 4.Finally a different approach to the preservation of embryos, named vitrification, is introduced. This procedure depends upon the ability of concentrated solutions of cryoprotective agents such as glycerol and propanediol to supercool to very low temperature (-196$^{\circ}C$) during rapid cooling before solidifying without formation of ice. However, more complete data are necessary for successful vitrification of blastocysts.

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Comparison of Egress Modeling and Experiments for Joint Flow Rate in the Staircase (피난계단 합류 시 유동률에 대한 피난실험 및 모델링 비교)

  • Hwang, Eun-Kyoung;Woo, Sujin;Kim, Jong-Hoon;Kim, Woon-Hyung
    • Fire Science and Engineering
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    • v.28 no.6
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    • pp.41-46
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    • 2014
  • Junction at the staircase is one of key factors for building egress analysis. The most important factor is the congestion at the door or somewhere connecting from bigger area to smaller one. The other factor is the congestion in the staircase. It happens when people from upper floors meets people from the connecting floor. Especially egress situation at the high-rise building is worse. The simulation of the junction is only described by physical agent algorithms in egress model. For that reason, the description of phenomena will validate with the result of experiment and estimate the gap between modeling and experiment. In this research, the experiment of the junction and the simulation was conducted and validated. The gap between the experiment and the modeling was estimated. The flow rates of modeling were lower than the modeling.

Ameliorative Effect of Schisandra chinensis and Ribes fasciculatum Extracts on Hydrogen Peroxide-Induced Neuronal Cell Death in Neuroblastic PC12 Cells and the Scopolamine-Induced Cognitive Impairment in a Rat Model (오미자칠해목 추출물의 과산화수소로 유발된 PC12뇌세포 사멸과 스코폴라민으로 유발된 렛드 동물모델에 대한 개선 효과)

  • Park, Eun-kuk;Han, Kyung-Hoon;Heo, Jae-Hyeok;Kim, Nam-Ki;Bae, Mun-Hyoung;Seo, Young-Ha;Yong, Yoon-joong;Jeong, Seon-Yong;Choi, Chun-Whan
    • The Korean Journal of Food And Nutrition
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    • v.33 no.3
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    • pp.347-355
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    • 2020
  • Cognitive impairment is considered to be key research topics in the field of neurodegenerative diseases and in understanding of learning and memory. In the present study, we investigated neuroprotective effects of Schisandra chinensis (SC) and Ribes fasciculatum (RF) extracts in hydrogen peroxide-induced neuronal cell death in vitro and scopolamine-induced cognitive impairment in Sprague Dawley® (SD) rat in vivo. Apoptotic cell death in neuroblastic PC12 cell line was induced by hydrogen peroxide for 1 hour at 100 μM. However, mixture of SC and RF treatment prevented peroxide induced PC12 cell death with no neurotoxic effects. For in vivo experiment, the effect of SC and RF extracts on scopolamine-induced cognitive impairment in SD rat was evaluated by spontaneous alternation behavior in Y-Maze test. After 30 min scopolamine injection, the scopolamine-induced rats presented significantly decreased % spontaneous alteration and acetylcholine level, compared to non-induced group. However, treatment of SC+RF extracts rescued the reduced % spontaneous alteration with acetylcholine concentration from hippocampus in scopolamine-induced rats. These results suggested that mixture of SC and RF extract may be a potential natural therapeutic agent for the prevention of cognitive impairment.

A Study on New Shielding Method for Minimizing Thyroid Oran Dose on Chest Radiography Used Automatic Exposure Control (자동노출조절장치를 이용한 흉부 방사선검사 시 갑상샘 장기선량 최소화를 위한 새로운 차폐 방법에 관한 연구)

  • Joo, Young-Cheol;Hong, Dong-Hee;Han, Beom-Hee
    • Journal of radiological science and technology
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    • v.43 no.5
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    • pp.323-329
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    • 2020
  • The purpose of this study is to investigate the effect of radiation shielding on the thyroid organ dose and image quality during Chest PA examination using automatic exposure control system. This study was conducted in the patient posture and examination conditions such as Chest PA using human model phantom. An experiment without shielding was set as a control group (non) and the cases of using paper coated with a contrast agent (contrast) and bismuth (bismuth) were used as experimental groups. Compared to non-shielded(non), the dose at bismuth increased about 7% in C(cervical vertebrae)5 and C6 and 14% in C7 and contrast showed dose increases of about 17 to 19% in C5 and C6 and about 21% in C7. As a result of the image quality comparison, when measured in the center of the cervical vertebrae, both SNR and CNR in bismuth increased about 40% higher than non, and contrast showed about 8 to 9% improvement. Compared with soft tissues of the cervix, bismuth reduced SNR by about 15% and CNR by about 13%, in contrast, SNR decreased by 11%, and CNR decreased by about 10%. In the Chest PA using AEC, the method of using the shield in front of the collimator has the advantage to observe the anatomical structure of the neck area well compared to the method using the lead. However, the dose at the neck can be increased by 7-21% depending on shielding materials.

Mechanisms of 5-azacytidine-induced damage and repair process in the fetal brain

  • Ueno, Masaki
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2006.11a
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    • pp.55-64
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    • 2006
  • The fetal central nervous system (CNS) is sensitive to diverse environmental factors, such as alcohol, heavy metals, irradiation, mycotoxins, neurotransmitters, and DNA damage, because a large number of processes occur during an extended period of development. Fetal neural damage is an important issue affecting the completion of normal CNS development. As many concepts about the brain development have been recently revealed, it is necessary to compare the mechanism of developmental abnormalities induced by extrinsic factors with the normal brain development. To clarify the mechanism of fetal CNS damage, we used one experimental model in which 5-azacytidine (5AZC), a DNA damaging and demethylating agent, was injected to the dams of rodents to damage the fetal brain. 5AzC induced cell death (apoptosis)and cell cycle arrest in the fetal brain, and it lead to microencephaly in the neonatal brain. We investigated the mechanism of apoptosis and cell cycle arrest in the neural progenitor cells in detail, and demonstrated that various cell cycle regulators were changed in response to DNA damage. p53, the guardian of genome, played a main role in these processes. Further, using DNA microarray analysis, tile signal cascades of cell cycle regulation were clearly shown. Our results indicate that neural progenitor cells have the potential to repair the DNA damages via cell cyclearrest and to exclude highly affected cells through the apoptotic process. If the stimulus and subsequent DNA damage are high, brain development proceeds abnormally and results in malformation in the neonatal brain. Although the mechanisms of fetal brain injury and features of brain malformation afterbirth have been well studied, the process between those stages is largely unknown. We hypothesized that the fetal CNS has the ability to repair itself post-injuring, and investigated the repair process after 5AZC-induced damage. Wefound that the damages were repaired by 60 h after the treatment and developmental processes continued. During the repair process, amoeboid microglial cells infiltrated in the brain tissue, some of which ingested apoptotic cells. The expressions of genes categorized to glial cells, inflammation, extracellular matrix, glycolysis, and neurogenesis were upregulated in the DNA microarray analysis. We show here that the developing brain has a capacity to repair the damage induced by the extrinsic stresses, including changing the expression of numerous genes and the induction of microglia to aid the repair process.

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Comparison of Piroxicam Pharmacokinetics and Anti-Inflammatory Effect in Rats after Intra-Articular and Intramuscular Administration

  • Park, Chan Woong;Ma, Kyung Wan;Jang, Sun Woo;Son, Miwon;Kang, Myung Joo
    • Biomolecules & Therapeutics
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    • v.22 no.3
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    • pp.260-266
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    • 2014
  • This study evaluated the pharmacokinetic profile and therapeutic efficacy of piroxicam (PX), a long acting non-steroidal anti-inflammatory drug for the treatment of arthritis, following intra-articular (IA) injection in comparison to the pharmacokinetic profile and therapeutic efficacy of PX after intramuscular (IM) injection. In the pharmacokinetic study in rats, systemic exposure and pharmacokinetic parameters of PX after a single IA dose were compared with systemic exposure and pharmacokinetic parameters of PX after administration of the same dose IM (0.6 mg/kg). The anti-inflammatory and analgesic effects of IA PX were evaluated simultaneously in a monoiodoacetate-induced osteoarthritis rat model. The plasma PX concentration rapidly rose following IA injection, and it was comparable to the plasma PX concentration following IM injection, suggesting the rapid efflux of the drug molecule from the joint cavity. However, in the efficacy study, the IA PX administration significantly reduced the knee swelling by reducing the level of prostaglandin $E_2$ in the joint, compared to that following administration of IA vehicle and after administration of the IM PX dose. In addition, we found that the anti-inflammatory and anti-nociceptive efficacies of IA PX were synergistically increased upon co-treatment with hyaluronic acid (HA), a potent agent for the treatment of osteoarthritis, at the weight ratio of 1:1 or 1:2, and these effects were more pronounced than those following administration of HA or PX alone. In conclusion, this study demonstrated the efficacy of the IA use of PX alone and/or in combination with HA in osteoarthritis.

Water soluble tomato concentrate regulates platelet function via the mitogen-activated protein kinase pathway

  • Jeong, Dahye;Irfan, Muhammad;Saba, Evelyn;Kim, Sung-Dae;Kim, Seung-Hyung;Rhee, Man Hee
    • Korean Journal of Veterinary Research
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    • v.56 no.2
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    • pp.67-74
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    • 2016
  • Tomato extract has been shown to exert antiplatelet activity in vitro and to change platelet function ex vivo, but with limitations. In this study, antiplatelet activity of water soluble tomato concentrate (Fruitflow I) and dry water soluble tomato concentrate (Fruitflow II) was investigated using rat platelets. Aggregation was induced by collagen and adenosine diphosphate and granule-secretion, $[Ca^{2+}]_i$, thromboxane B2, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) levels were examined. The activation of integrin ${\alpha}_{IIb}{\beta}_3$ and phosphorylation of signaling molecules, including mitogen-activated protein kinase (MAPK) and PI3K/Akt, were investigated by flow cytometry and immunoblotting, respectively. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were examined. Moreover, in vivo thrombus weight was tested by an arteriovenous shunt model. Fruitflow I and Fruitflow II significantly inhibited agonist induced platelet aggregation, adenosine triphosphate and serotonin release, $[Ca^{2+}]_i$, and thromboxane B2 concentration, while having no effect on cAMP and cGMP levels. Integrin ${\alpha}_{IIb}{\beta}_3$ activation was also significantly decreased. Moreover, both concentrates reduced phosphorylation of MAPK pathway factors such as ERK, JNK, P38, and PI3K/Akt. In vivo thrombus formation was also inhibited. Taken together, these concentrates have the potential for ethnomedicinal applications to prevent cardiovascular ailments and can be used as functional foods.

Detection and Molecular Identification of Human Enteric Viruses in Urban Rivers in Korea

  • Lee, Cheong-Hoon;Kim, Sang-Jong
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2008.05a
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    • pp.171-171
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    • 2008
  • We monitored the occurrence of human enteric viruses in urban rivers by cell culture-PCR and RT-nested PCR. Water samples were collected monthly or semimonthly between May 2002 and March 2003 in four urban tributaries. Enteric viruses were detected by RT-nested PCR and cell culture-PCR based on a combination of Buffalo Green monkey kidney (BGMK) and A549 cell lines, followed by phylogenetic analysis of amplicons. By RT-nested PCR analysis, 45 (77.6%), 32 (55.2%), 32 (55.2%), 26 (44.8%), 12 (20.7%), 2 (3.4%), 4 (6.9%), and 4 (6.9%) of 58 samples showed positive results with adenoviruses, enteroviruses, noroviruses (NV) genogroup I (GI) and II (GII), reoviruses, hepatitis A viruses, rotaviruses and sapoviruses, respectively. Adenoviruses were most often detected and only eight (13.8%) samples were negative for adenoviruses and positive for other enteric viruses in the studied sites. Thirty-one (77.5%) of the 40 samples were positive for infectious adenoviruses and/or enteroviruses based on cell culture-PCR, and the frequency of positive samples grown on A549 and BGMK (65.0%) was higher than that grown on BGMK alone (47.5%). The occurrence of each enteric virus, except reoviruses and hepatitis A viruses was not statistically correlated with the water temperature and levels of fecal coliforms according to Binary logistic regression model. By sequence analysis, most strains of adenoviruses and enteroviruses detected in this study are similar to the causative agent of viral diseases in Korea and most NV GI- and GII-grouped strains were closely related to the reference strains from China and Japan, and GII/4-related strains had similar sequences to strains recognized as a worldwide epidemic outbreak. Our results suggested that monitoring human enteric viruses is necessary to improve microbial quality and cell culture-PCR using the combination of A549 and BGMK cells and the adenovirus detection by PCR could be useful for monitoring viral contamination in the aquatic environment.

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Effect of Lithospermi Radix on Contact Dermatitis Induced by Dinitrofluorobenzene in Mice

  • Kim, Han-Na;Kim, Mi-Young;Choi, Chan-Hun;Kim, Byung-Joo;Kim, Kyung-Yoon;Kim, Gye-Yeop;Jeong, Hyun-Woo;Kim, Hyung-Woo
    • Journal of Pharmacopuncture
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    • v.15 no.2
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    • pp.7-10
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    • 2012
  • Objectives: The root of Lithospermum erythrorhizon Sieb. et Zucc. (Lithospermi Radix, LR) is a kind of heat clearing and blood cooling medicinal herbs. It can clear away heat and cool the blood, reduce toxins and disperse maculae. LR has long been used as efficacious therapy for inflammation, burns, frostbite and skin diseases such as eczema and psoriasis. Methods: In the present study, we investigate anti-allergic and anti-inflammatory effects of LR by using the 1-fluoro-2, 4- dinitrofluorobenzene (DNFB)-induced contact dermatitis mouse model. Results: Topical application of 10 mg/mL of LR effectively inhibited skin lesions induced by repeated paintings with DNFB. Topical application of LR also inhibited hyperplasia, edema, spongiosis and infiltrations of mononuclear cells. In addition, production levels of total immunoglobulin and IgG1 in serum were decreased by using LR in vivo. Conclusions: These data suggest that LR acts as an antiinflammatory agent, improving skin lesions in CD mice.