• 제목/요약/키워드: accumulating studies

검색결과 136건 처리시간 0.026초

체류시간과 교체시간 계산을 통한 가막만의 시·공간적 해수교환 특성 연구 (A Study on Temporal-Spatial Water Exchange Characteristics in Gamak Bay using a Method for Calculating Residence Time and Flushing Time)

  • 김진호;이원찬;홍석진;박정현;김청숙;정우성;김동명
    • 한국환경과학회지
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    • 제25권8호
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    • pp.1087-1095
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    • 2016
  • The concepts of residence time and flushing time can be used to explain the exchange and transport of water or materials in a coastal sea. The application of these transport time scales are widespread in biological, hydrological, and geochemical studies. The water quality of the system crucially depends on the residence time and flushing time of a particle in the system. In this study, the residence and flushing time in Gamak Bay were calculated using the numerical model, EFDC, which includes a particle tracking module. The average residence time was 55 days in the inner bay, and the flushing time for Gamak Bay was about 44.8 days, according to the simulation. This means that it takes about 2 months for land and aquaculture generated particles to be transported out of Gamak Bay, which can lead to substances accumulating in the bay. These results show the relationships between the transport time scale and physical the properties of the embayment. The findings of this study will improves understanding of the water and material transport processes in Gamak Bay and will be important when assessing the potential impact of coastal development on water quality conditions.

Ginsenoside Rg3의 항암효능 연구의 진보 (Recent Progress in Research on Anticancer Activities of Ginsenoside-Rg3)

  • 남기열;최재을;홍세철;표미경;박종대
    • 생약학회지
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    • 제45권1호
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    • pp.1-10
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    • 2014
  • Ginsenoside Rg3 (G-Rg3) is one of protopanaxadiol ginsenosides characteristic of red ginseng, steamed and dried ginseng (Panax ginseng), which has recently attracted much attention for its antitumor properties in vitro and in vivo animal models. Experimental studies have demonstrated that it could promote cancer cell apoptosis, inhibit cancer cell growth, the apoptosis of cancer cells, adhesion, invasion and metastasis, and also prevent an angiogenetic formation in prostate, breast, ovarian, colorectal, gastric, liver and lung cancer etc. It has shown the antitumor activities by modulation of diverse signaling pathways, including regulation of cell proliferation mediators (CDKs and cyclins), growth factors (vascular endothelial growth factor), tumor suppressors (p53 and p21), cell death mediators (caspases, Bcl-2, Bax), inflammatory response molecules ($NF-{\kappa}B$ and COX-2), protein kinases (JNK, Akt, and AMP-activated protein kinase) and Wnt/${\beta}$-catenin signaling. In addition, the combination of Rg3 and chemotherapeutic agents have synergistically enhanced therapeutic efficacy and reduced antagonistically side effects. Furthermore, it can reverse the multidrug resistance of cancer cells, prolong the survival duration and improve life quality of cancer patients. Taken together, accumulating evidences could provide the potential of G-Rg3 in the treatment of cancers and the feasibility of further randomized placebo controlled clinical trials.

문화예술교육에서의 융복합 학문의 시대적 흐름- 음악테크놀로지를 중심으로 (Trend of the Convergence Stud in Arts & Culture Education - Focused on Music Technology)

  • 김은진;임병노
    • 한국콘텐츠학회논문지
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    • 제12권3호
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    • pp.102-113
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    • 2012
  • 디지털 테크놀로지 시대에 새로운 가치를 추구하려는 노력은 사회 문화 전반 분야뿐만이 아닌 일반 교육계와 문화, 예술교육에도 변화를 요구하고 있다. 가장 큰 변화의 하나는 다른 영역간의 통합과 연계라는 추세가 문화와 예술분야에도 영향을 주면서, 문화와 예술이 통합을 이룬 문화예술 교육을 탄생하기에 이르렀다. 또한 새로운 시대는 디지털 테크놀로지의 활용이 교육 전 영역에서 활발히 사용되고 있으며, 문화 예술교육에도 테크놀로지의 활용이라는 새로운 시도를 요구하고 있다. 본 연구는 음악 테크놀로지를 활용한 문화예술교육에 대하여 이론적으로 알아보았다. 음악 테크놀로지의 활용은 다른 교과간의 통합적 접근으로의 가능성을 보여주며, 문화예술교육 외에 다양한 학문에도 적용이 가능함을 보여주었다. 음악 테크노로지의 활용은 현재 문화예술 교육 분야의 독특성, 전문성, 고유성을 반영해줄 만한 교수학습방법의 학습도구로서 다양한 대상과 상황에서 적용하여 실천적 사례를 쌓음으로서 문화예술 교육 분야를 위한 새로운 교수학습방법으로서의 역할을 할 수 있으리라 생각한다.

스마트코리아 추진을 위한 스마트 플랫폼 구현 전략 (Smart Platform Strategies for Smart Korea)

  • 윤용익;김은주;엄리영
    • 한국컴퓨터정보학회논문지
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    • 제16권12호
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    • pp.235-246
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    • 2011
  • 현재 우리는 사회, 문화, 정치, 경제, 기술에 있어 국가 간의 경계가 무너지는 글로벌화와 다 분야 기술의 컨버전스 및 이종 서비스의 융합이 광범위하게 진행되는 시대에 살고 있고, 이러한 변화의 물결은 지식과 정보 사회를 넘어서 스마트 사회로의 진입을 재촉하고 있다. 과거에는 방대한 양의 지식과 정보를 생성하고, 가공하며, 축적하는 것에 집중했다면, 현재 사회는 이러한 축적된 지식과 정보를 시공간의 제약 없이, 보다 지능적이면서, 저렴하게, 융합된 형태로 제공될 수 있기를 기대하고 있다. 본 논문에서는 스마트서비스의 개념과 다양한 사례를 살펴보고 지식 정보사회의 서비스 통합 패러다임을고려하여스마트서비스 제공을 위한 플랫폼으로서의 구현요소와 서비스플랫폼 현황분석, 관련기관별 주요역할, 구현요소확보방안 등 스마트 플랫폼 구현전략을 제시하였다.

3D 컴퓨터 그래픽을 이용한 입체 애니메이션 콘텐츠 제작기법 연구 (Research on the Technique to Produce Stereoscopic Animation Contents using 3D Computer Graphics)

  • 김정현
    • 한국콘텐츠학회논문지
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    • 제12권1호
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    • pp.112-124
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    • 2012
  • 디지털 테크놀로지의 획기적인 발전과 3D 입체영화의 성공사례로 입체영상이 주목받기 시작하였다. 그러나 입체영상은 과거처럼 일시적인 붐으로 그치지 않고, 지속적인 가능성을 보여주고 있다. 하지만 국내의 입체영상 시장에서는 자본력 부족, 제작 인프라 미흡, 2D to 3D 제작 등의 이유로 다양하고 창의적인 입체 애니메이션 콘텐츠를 제작하기가 쉽지 않다. 이로 인해 국내에서는 제작기법에 대한 풍부한 자료 축적에 대한 노력이 절실히 요구되어지는 실정이다. 본 논문에서는 고품질의 입체 콘텐츠 제작에 있어서 필요로 하는 입체를 고려한 연출과 효과적인 입체 구현을 위해 3D 그래픽을 기반으로 연구한 제작기법에 대해 설명하였다. 분명, 입체 영상은 21세기 디지털 콘텐츠 산업에 있어서 가장 기대되는 영상 콘텐츠 중 하나이다. 그렇기 때문에 양질의 입체 애니메이션 콘텐츠를 제작하기 위해서는 기본적인 연구부터 지속적으로 신중히 다가가야 할 것이다.

Biological functions of histidine-dipeptides and metabolic syndrome

  • Song, Byeng Chun;Joo, Nam-Seok;Aldini, Giancarlo;Yeum, Kyung-Jin
    • Nutrition Research and Practice
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    • 제8권1호
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    • pp.3-10
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    • 2014
  • The rapid increase in the prevalence of metabolic syndrome, which is associated with a state of elevated systemic oxidative stress and inflammation, is expected to cause future increases in the prevalence of diabetes and cardiovascular diseases. Oxidation of polyunsaturated fatty acids and sugars produces reactive carbonyl species, which, due to their electrophilic nature, react with the nucleophilic sites of certain amino acids. This leads to formation of protein adducts such as advanced glycoxidation/lipoxidation end products (AGEs/ALEs), resulting in cellular dysfunction. Therefore, an effective reactive carbonyl species and AGEs/ALEs sequestering agent may be able to prevent such cellular dysfunction. There is accumulating evidence that histidine containing dipeptides such as carnosine (${\beta}$-alanyl-L-histidine) and anserine (${\beta}$-alanyl-methyl-L-histidine) detoxify cytotoxic reactive carbonyls by forming unreactive adducts and are able to reverse glycated protein. In this review, 1) reaction mechanism of oxidative stress and certain chronic diseases, 2) interrelation between oxidative stress and inflammation, 3) effective reactive carbonyl species and AGEs/ALEs sequestering actions of histidine-dipeptides and their metabolism, 4) effects of carnosinase encoding gene on the effectiveness of histidine-dipeptides, and 5) protective effects of histidine-dipeptides against progression of metabolic syndrome are discussed. Overall, this review highlights the potential beneficial effects of histidine-dipeptides against metabolic syndrome. Randomized controlled human studies may provide essential information regarding whether histidine-dipeptides attenuate metabolic syndrome in humans.

미생물에 의한 핵산관련물질의 생산에 관한 연구(제3보)-Bacillus subtilis의 영양요구변이주에 의한 Hypoxanthine의 축적- (Studies on Production of Nucleic Acid Derivatives by Microorganisms (III) -Accumulation of Hypoxanthine by Adenineless Mutant of Bacillus subtilis-)

  • 배무;윤애숙;이계준
    • 한국미생물·생명공학회지
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    • 제1권1호
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    • pp.13-18
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    • 1973
  • Bacillus subtilis의 생균 및 포자액을 자외선 조사와 diethylsulfate 처리로서 adenine 요구변이주 총 62주를 분리하였다. 이들 변이주는 발효배지에 자외선흡수 물질을 축적하고 있음을 확인하였으며 이 축적물은 thin-layer chromatogram 자외선흡수 곡선등으로 hypozanthine, uracil 임을 동정하였다. 이 중에서 hypoxanthine만을 축적하는 변이주 BS-137의 배지성분을 검토한 결과 탄소원소로서는 glucose가 좋았으며 질소원으로서는 yeastext와 NaNO$_3$ 가 적당하였다. 아울러 배양액으로부터 hypoxanthine을 분리 정제하는 방법을 확립하였다.

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Modulation of Human Cardiac Progenitors via Hypoxia-ERK Circuit Improves their Functional Bioactivities

  • Jung, Seok Yun;Choi, Sung Hyun;Yoo, So Young;Baek, Sang Hong;Kwon, Sang Mo
    • Biomolecules & Therapeutics
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    • 제21권3호
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    • pp.196-203
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    • 2013
  • Recent accumulating studies have reported that hypoxic preconditioning during ex vivo expansion enhanced the self-renewal or differentiation of various stem cells and provide an important strategy for the adequate modulation of oxygen in culture conditions, which might increase the functional bioactivity of these cells for cardiac regeneration. In this study, we proposed a novel priming protocol to increase the functional bioactivity of cardiac progenitor cells (CPCs) for the treatment of cardiac regeneration. Firstly, patient-derived c-$kit^+$ CPCs isolated from the atrium of human hearts by enzymatic digestion and secondly, pivotal target molecules identified their differentiation into specific cell lineages. We observed that hCPCs, in response to hypoxia, strongly activated ERK phosphorylation in ex vivo culture conditioning. Interestingly, pre-treatment with an ERK inhibitor, U0126, significantly enhanced cellular proliferation and tubular formation capacities of CPCs. Furthermore, we observed that hCPCs efficiently maintained the expression of the c-kit, a typical stem cell marker of CPCs, under both hypoxic conditioning and ERK inhibition. We also show that hCPCs, after preconditioning of both hypoxic and ERK inhibition, are capable of differentiating into smooth muscle cells (SMCs) and cardiomyocytes (CMs), but not endothelial cells (ECs), as demonstrated by the strong expression of ${\alpha}$-SMA, Nkx2.5, and cTnT, respectively. From our results, we conclude that the functional bioactivity of patient-derived hCPCs and their ability to differentiate into SMCs and CMs can be efficiently increased under specifically defined culture conditions such as short-term hypoxic preconditioning and ERK inhibition.

Analysis of Biological Effect of DBD-type Non-thermal Atmospheric Pressure Plasma on Saccharomyces Cerevisiae

  • Park, Gyung-Soon;Baik, Ku-Yeon;Kim, Jung-Gil;Kim, Yun-Jung;Lee, Kyung-Ae;Choi, Eun-Ha;Uhm, Hwan-Sup;Jung, Ran-Ju;Cho, Kwang-Sup
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.337-337
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    • 2011
  • Application of plasma technology on microbial sterilization has been frequently studied. In spite of accumulating number of studies, many have been focused on bacteria. Reports on eukaryotic yeasts and filamentous fungi are limited. In addition, mechanism of plasma effect still needs to be clarified. In this study, we analyzed the effect of non-thermal atmospheric pressure plasma on the budding yeast, Saccharomyces cerevisiae using DBD-type device. When yeast cells were exposed to plasma (at 2 mm distance) and then cultured on YPD-agar plate, number of cells survived (shown as colony) were reduced proportionally to exposure time. More than 50% reduction in number of colonies were observed after twice exposure of 5min. each. Colonies much smaller than those of control (no plasma exposure) were appeared after twice exposure of 5 min. each. It seems that small colonies are resulted from delayed cell growth due to the damage caused by plasma treatment. Microscopic analysis demonstrates that yeast cells treated with plasma for 5 min. twice have more rough and shrinked shape compared to oval shape with smooth surface of control.

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Comparative In Vitro Biological Toxicity of Four Kinds of Air Pollution Particles

  • Shin, Han-Jae;Cho, Hyun Gi;Park, Chang Kyun;Park, Ki Hong;Lim, Heung Bin
    • Toxicological Research
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    • 제33권4호
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    • pp.305-313
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    • 2017
  • Accumulating epidemiological evidence indicates that exposure to fine air pollution particles (APPs) is associated with a variety of adverse health effects. However, the exact physiochemical properties and biological toxicities of fine APPs are still not well characterized. We collected four types of fine particle (FP) (diesel exhaust particles [DEPs], natural organic combustion [NOC] ash, synthetic organic combustion [SOC] ash, and yellow sand dust [YSD]) and investigated their physicochemical properties and in vitro biological toxicity. DEPs were almost entirely composed of ultrafine particles (UFPs), while the NOC, SOC, and YSD particles were a mixture of UFPs and FPs. The main elements in the DEPs, NOC ash, SOC ash, and YSD were black carbon, silicon, black carbon, and silicon, respectively. DEPs exhibited dose-dependent mutagenicity even at a low dose in Salmonella typhimurium TA 98 and 100 strains in an Ames test for genotoxicity. However, NOC, SOC, and YSD particles did not show any mutagenicity at high doses. The neutral red uptake assay to test cell viability revealed that DEPs showed dose-dependent potent cytotoxicity even at a low concentration. The toxicity of DEPs was relatively higher than that of NOC, SOC, and YSD particles. Therefore, these results indicate that among the four FPs, DEPs showed the highest in vitro biological toxicity. Additional comprehensive research studies such as chemical analysis and in vivo acute and chronic inhalation toxicity tests are necessary to determine and clarify the effects of this air contaminant on human health.