• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.518-526
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• 2013

Gut-derived lipopolysaccharides (LPS) are critical to the development and progression of chronic low-grade inflammation and metabolic diseases. In this study, the effects of probiotics Lactobacillus and Bifidobacterium on gut-derived lipopolysaccharide and inflammatory cytokine concentrations were evaluated using a human colonic microbiota model. Lactobacillus reuteri, L. rhamnosus, L. plantarum, Bifidobacterium animalis, B. bifidum, B. longum, and B. longum subsp. infantis were identified from the literature for their anti-inflammatory potential. Each bacterial culture was administered daily to a human colonic microbiota model during 14 days. Colonic lipopolysaccharides, and Gram-positive and negative bacteria were quantified. RAW 264.7 macrophage cells were stimulated with supernatant from the human colonic microbiota model. Concentrations of TNF-${\alpha}$, IL-$1{\beta}$, and IL-4 cytokines were measured. Lipopolysaccharide concentrations were significantly reduced with the administration of B. bifidum ($-46.45{\pm}5.65%$), L. rhamnosus ($-30.40{\pm}5.08%$), B. longum ($-42.50{\pm}1.28%$), and B. longum subsp. infantis ($-68.85{\pm}5.32%$) (p < 0.05). Cell counts of Gram-negative and positive bacteria were distinctly affected by the probiotic administered. There was a probiotic strain-specific effect on immunomodulatory responses of RAW 264.7 macrophage cells. B. longum subsp. infantis demonstrated higher capacities to reduce TNF-${\alpha}$ concentrations ($-69.41{\pm}2.78%$; p < 0.05) and to increase IL-4 concentrations ($+16.50{\pm}0.59%$; p < 0.05). Colonic lipopolysaccharides were significantly correlated with TNF-${\alpha}$ and IL-$1{\beta}$ concentrations (p < 0.05). These findings suggest that specific probiotic bacteria, such as B. longum subsp. infantis, might decrease colonic lipopolysaccharide concentrations, which might reduce the proinflammatory tone. This study has noteworthy applications in the field of biotherapeutics for the prevention and/or treatment of inflammatory and metabolic diseases.

• 한국콘텐츠학회논문지
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• 제22권7호
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• pp.670-675
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• 2022

4차 산업혁명의 시대는 모든 것이 데이터 중심이다. 데이터의 종류와 양이 중심이 될 수도 있고, 특수한 상황에서 요구하는 새로운 데이터가 필요할 때도 있다. 3D프린터가 다양한 분야에 활용되면서 새롭게 도전을 받는 분야들이 있다. 특히 의료 관련 분야에서 그동안 생각도 하지 못했던 새로운 시도가 일어나고 있다. 본 논문에서는 인체 데이터 중에도 인체 물성이 요구되는 분야에 연구를 가능하게 하기 위한 연구이다. 그동안 인체 장기를 활용한 연구에서는 주로 실리콘 소재로 만들어진 데이터를 활용하였다. 시신으로부터 인체 물성을 측정하고, 이 물성을 반영한 신소재를 개발하고, 3D프린터로 인공 장기를 개발한다. 이렇게 만들어진 인공장기를 활용하여 신장결석 제거용 로봇으로 수술하는 연습을 할 수 있도록 한다. 본 논문에서는 사람의 실제 장기와 유사한 첨단 소재를 개발하기 위한 일련의 연구 과정을 소개하고자 한다.

• Korea-Australia Rheology Journal
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• 제16권3호
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• pp.141-146
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• 2004

Shear-induced damage of Red Blood Cell (RBC) is an imminent problem to be solved for the practical application of artificial organs in extra corporeal circulation, as it often happens and affects physiological homeostasis of a patient. To design and operate artificial organs in a safe mode, many investigations have been set up to correlate shear and shear-induced cell damage. Most studies were focused on hemolysis i.e. the extreme case, however, it is important as well to obtain a clear understanding of pre-hemolytic mechanical damage. In this study, the change in deformability of RBC was measured by ektacytometry to investigate the damage of RBC caused by shear. To a small magnitude of pre-shear, there is little difference, but to a large magnitude of pre-shear, cell damage occurs and the effect of shear becomes significant depending on both the magnitude and imposed time of shearing. The threshold stress for cell damage was found to be approximately 30 Pa, which is much less than the threshold of mechanical hemolysis but is large enough to occur in vitro as in the extra corporeal circulation during open-heart surgery or artificial heart. In conclusion, it was found and suggested that the decrease of deformability can be used as an early indication of cell damage, in contrast to measuring plasma hemoglobin. As cell damage always occurs during flow in artificial organs, the results as well as the approach adopted here will be helpful in the design and operation of artificial organs.

• Journal of Mechanical Science and Technology
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• 제20권8호
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• pp.1118-1124
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• 2006

Recently, cavitation on the surface of mechanical heart valve has been studied as a cause of fractures occurring in implanted Mechanical Heart Valves (MHVs). It has been conceived that the MHVs mounted in an artificial heart close much faster than in vivo sue, resulting in cavitation bubbles formation. In this study, six different kinds of mono leaflet and bileaflet valves were mounted in the mitral position in an Electro-Hydraulic Total Artificial Heart (EHTAH), and we investigated the mechanisms for MHV cavitation. The valve closing velocity and a high speed video camera were employed to investigate the mechanism for MHV cavitation. The closing velocity of the bileaflet valves was slower than that of the mono leaflet valves. Cavitation bubbles were concentrated on the edge of the valve stop and along the leaflet tip. It was established that squeeze flow holds the key to MHV cavitation in our study. Cavitation intensity increased with an increase in the valve closing velocity and the valve stop area. With regard to squeeze flow, the bileaflet valve with slow valve-closing velocity and small valve stop areas is better able to prevent blood cell damage than the monoleaflet valves.

• 멤브레인
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• 제33권2호
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• pp.61-69
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• 2023

최근 COVID-19로 인해 증가한 급성 폐부전 중증환자 치료를 위한 인공폐 기술의 필요성이 부각되었다. 또한, 빠르게 진행되고 있는 인구고령화는 인공장기(artificial organ, AO) 기술에 대한 높은 수요를 불가피하게 만들고 있다. 분리막은폐, 신장, 간 및 췌장을 포함한 많은 AO 기기의 핵심 부품이다. 특히 인공폐(artificial lung, AL) 기술은 지난 50년간 빠르게 발전해왔지만, 장기부전 환자의 생존율은 50% 내외로 여전히 낮은 편이다. 현재 대부분의 AL 관련문헌은 임상결과에 집중되어 있으며, AL 분리막의 개발연구는 매우 부족한 편이다. 이에 대한 원인 중 하나는 AL 기술이 생명공학을 포함하여 고분자 화학 및 분리공정 기술을 아우르는 융합적 기술개발을 요구하기 때문인 것으로 판단된다. 본 총설에서는 헬스케어산업에서 AL 분리막 기술의 역할과 기술개발이 필요한 난제들을 정리하였다. 특히, 분리막 소재의 혈액적합성, 분리성능, 모듈 디자인 및 공정 구성 측면에서 다양한 연구개발이 필요하다는 부분을 강조하고자 한다.

• 수산해양교육연구
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• 제28권3호
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• pp.653-660
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• 2016

Snakehead, Channa argus were intraperitoneally infected with Nocardia seriolae. at the concentrations of $1.5{\times}10^7cfu/m{\ell}$ or $1.5{\times}10^8cfu/m{\ell}$. The infected fish were kept in aquaria at $25^{\circ}C$ and $30^{\circ}C$ for 3 weeks. Clinical signs and mortality were monitored daily to evaluate the virulence. All artificially infected fish showed the same clinical sign found in naturally infected fish. All the fish infected with $1.5{\times}10^8cfu/m{\ell}$ of N. seriolae died within 24days. N. seriolae showed higher virulence to snakehead at the temperature $30^{\circ}C$. Internal lesions such as whitish nodules in the infected internal organs were not correlated with mortality but some degenerative changes were observed in all the infected organs within a week. Whitish nodules in the infected organs which are the typical character in nocardial infection was initially found at two weeks after the artificial infection in snakehead.

• 한국임상수의학회지
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• 제16권1호
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• pp.128-137
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• 1999

Plasma progesterone (P$_4$) concentrations were measured for confirming the estrus observation and for the early pregnancy diagnosis in 130 cows of small farmers. Ultrasonographic examinations were performed from day 30 after artificial insemination to establish the characteristic ultrasonographic appearances of gestational structures in each pregnant stages. Of the 130 cows inseminated, 111 cows (85.4%) were an ovulatory estrus, 12 cows (9.2%) were an unovulatory estrus, and 7 cows (5.4%) were the error of estrus detection, respectively. The accuracy for early pregnancy diagnosis in 111 ovulatory estrus cows achieved when the discriminatory concentration at day 21 after artificial insemination was placed at 3.0 ng-/ml in plasma, was 86.7 % for positive diagnosis and 100% for negative diagnosis, respectively. Pregnancy diagnosis by ultrasonography were performed to evaluate gestational structures from day 30 after artificial insemination in 83 cows. Pregnant cows were 72 of 83 cows. The characteristic ultrasonography of gestational structures in each gestational stages was as follows. The embryo proper was observed within anechoic fetal fluid between 28 and 40 days after insemination, and amnion and embryonic heartbeat was also detected in this period. Between days 41 and 50, embryo proper was detected as an discriminated from head and body, and forelimb buds and hindlimb buds were also observed in this period. Between days 51 and 60, an embryo proper was clearly discriminated from head and body, and fetal movement, forelimb buds and hindlimb buds were observed in this period. Between days 61 and 70, fetus was completely developed, and fetal skeleton, organs and cotyledon were observed. After day 71, each organs of fetus were rapidly developed and a fetus was partially observed in screen because fetus was too big and larger, These results indicate that plasma P$_4$ determination at days 0,6 and 21 after artificial insemination can be utilized for confirming the estrus observation and for early pregnancy diagnosis. Also, ultrasonography was reliable method for early pregnancy diagnosis at day 30 after artificial insemination.

• 전자공학회지
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• 제24권10호
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• pp.63-72
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• 1997

Application of MEMS to biologic system mainly categorized into bio-electronics and micro-medical systems, Bio-electronics concerns on the biocompatible electronic device, in-vivo sensors, the sensors based on biological materials, biological materials for electronics and optics, the concepts and materials Inspired by biology and useful for electronics, the algorithm inspired by biology, artificial sense, and the biologic-inorganic hybrids. Micro-medical systems are utilited into the drug delivery systems, micro patient monitoring systems, micro prosthesis and artificial organs, cardiology related prothesis, analysis systems, and the minimal invasive surgery tools based on the m icrom achining technology.

• 한국고분자학회지:고분자과학과기술
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• 제5권6호
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• pp.537-543
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• 1994

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.129-130
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• 1994

The science of toxicology is the understanding of the mechanisms by which exogenous agents produce deleterious effects in biological systems. The actions of chemicals such as drugs are ultimately exerted at the cellular and gene levels. Over the past decade. several in vitro alternative methods such as cultured cells for assessing the toxicity of various xenobiotics have been proposed to reduce the use of animals. In this workshop three advanced methods will be presented. These methods are novel important models for toxicologic studies. Dr. Tabuchis group has establishcd two immortalized gastric surface mucosa cell lines from the pminary cultore of gastric fundic mucosal cells of adult transgenic mice harboring a temperature sensitive simian virus 40 large T-anugen gene. As the immortalized cell lines of various tissues possess unique characteristics to maintain their normal functions for several months, these cell lines are extremely useful for not only toxicity testing but also pharmacological screening in new drug development. Professor Funatsu have studied the formation of spherical multicelluar aggregates of adult rat hepatocytes(spheroid) having tissue like structure. The sphcroid shown thre is a prototype module of an artificial liver support system. Thus, the urea synthesis activity of the artificial liver was maintained at least to days in 100％ rat blood plasma. Dr. Takezawa and his coworkers have developed a novel culture system of multicellular spheroids considered 〃organoids〃 by utilizing a thermo-responsive polymer as a substratum of anchorage dependent cells. His final goal is to reconstitute the organoids of various normal organs, e.g., liver, skin etc. and also abnormal deseased organs such as tumor.