• Clinical and Experimental Reproductive Medicine
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• 제45권2호
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• pp.75-81
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• 2018

Objective: Recapitulation of the spermatogenesis process in vitro is a tool for studying the biology of germ cells, and may lead to promising therapeutic strategies in the future. In this study, we attempted to transdifferentiate Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) into male germ cells using all-trans retinoic acid and Sertoli cell-conditioned medium. Methods: Human WJ-MSCs were propagated by the explant culture method, and cells at the second passage were induced with differentiation medium containing all-trans retinoic acid for 2 weeks. Putative germ cells were cultured with Sertoli cell-conditioned medium at $36^{\circ}C$ for 3 more weeks. Results: The gene expression profile was consistent with the stage-specific development of germ cells. The expression of Oct4 and Plzf (early germ cell markers) was diminished, while Stra8 (a premeiotic marker), Scp3 (a meiotic marker), and Acr and Prm1 (postmeiotic markers) were upregulated during the induction period. In morphological studies, approximately 5% of the cells were secondary spermatocytes that had completed two stages of acrosome formation (the Golgi phase and the cap phase). A few spermatid-like cells that had undergone the initial stage of tail formation were also noted. Conclusion: Human WJ-MSCs can be transdifferentiated into more advanced stages of germ cells by a simple two-step induction protocol using retinoic acid and Sertoli cell-conditioned medium.

• 대한두개안면성형외과학회지
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• 제21권1호
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• pp.58-63
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• 2020

Spindle cell squamous cell carcinoma (SpSCC) is a biphasic tumor composed of squamous cell epithelial and spindle cell mesenchymal components, both of which are malignant. Cutaneous SpSCC can cause diagnostic and therapeutic difficulties because of its rarity, heterogeneity, morphological similarity to other cutaneous spindle cell neoplasms, and uncertain pathogenesis and prognosis, particularly when the squamous cell carcinoma component is minimal or missing. Intransit metastasis and satellite lesion (satellitosis) constitute a spectrum of non-nodal regional metastases. Here the author reports the first known case of cutaneous SpSCC presenting with intransit metastases and a satellite lesion, which were exceptionally aggressive. A 77-year-old female patient presented with a 3×3×0.5 cm mass on her right cheek. Despite wide excision and postoperative radiation, the patient resulted in local recurrence and multiple distant metastases within 3 months. If many high-risk factors-particularly satellitosis and in-transit metastases are observed in a tumor with epithelial to mesenchymal transition, then further wide excision and adjuvant chemoradiation should be considered early in the treatment process. A multidisciplinary approach could be the key to cure the most aggressive malignancies of the skin, as in other organs.

• 한국소음진동공학회논문집
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• 제21권8호
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• pp.714-719
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• 2011

This paper presents vibration characteristics of magnetorheological(MR) elastomer, whose elastic modulus are controllable by applied magnetic field. By using this property, the material can be applied to vibration absorber, so that the stiffness of the absorber can be changed and actively controlled according to the magnetic flux density. However, the various performances of MR elastomer depends on different polarized direction of particles by applied magnetic field and dimension during the manufacturing process. In this paper, in order to obtain the optimal characteristics of MR elastomer, MR elastomers with different types and dimensions are prepared for a series tests. Using this test setup, extent of natural frequency shifted against magnetic field at various excitation frequencies can be measured. Specimens are prepared with 3 types, as cylinder samples exposed to magnetic field vertically, horizontally and unexposed during cure, respectively. Also, a set of design variables are considered to produce MR elastomers. Through the modal tests of mass structure with MR elastomer, the optimal design as well as the polarization direction of MR elastomer is obtained among the various dimensions and 3 directional types of MR elastomers.

• 한국안전학회지
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• 제12권4호
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• pp.57-62
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• 1997

The combined structure of hybrid composite made through the bonding process of materials of different properties greatly defines its mechanical characteristics, as the results of the experiments on materials of different properties show much dissimilarity. When carbon/epoxy materials are applied to hybrid composite, the carbon materials helps to improve the mechanical properties of the hybrid composite, and the epoxy reduces its fracture strain and impact resistance. Carbon fiber which is now in general commercialization is classified as high modulus or high strength system, and its manufacturing methods are various. The study of the materials having combined structure is focused on the numerical analysis of the layers of bonding surface in materials with difference modulus. The hybrid composite made through the multilayered bonding of reinforced aluminium sheets with aramid fiber now faces the marketing phase, and especially its excellent fatigue resistance and mechanical properties promote active researches on the similar products of hybrid composite. This study aims to investigate the effects of CFRP volume ratio and fiber's orientation over the properties of mechanical strength and fatigue life of the hybrid composite, AI7075/CFRP. To carry out this study, static tensile and fatigue tests were given to some of the panels which, made through the co-cure processing in an autoclave, have different CFRP volume ratio and carbon fiber orientations.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.345-350
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• 2011

Antioxidant agent, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane were prepared and investigated the antioxidant activity on recycled rubber mat manufactured with waste tire powder. Mechanical properties of rubber mat are influenced by many factor such as compounding ingredients and state of cure, process of rubber, and fillers. Our study aim is to investigate influence of antioxidant activities on ozone cracking and the thermal aging time. In this work, the degradation of recycled rubber mat was studied and suggested mechanism to involve two-type of degradation, thermal aging and cracking both of which can be contained antioxidant or non-antioxidant agent.

• Clinical and Experimental Pediatrics
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• 제55권7호
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• pp.219-223
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• 2012

Since the first umbilical cord blood transplantation (CBT) in 1998, cord blood (CB) has now become one of the most commonly used sources of hematopoietic stem cells for transplantation. CBT has advantages of easy procurement, no risk to donor, low risk of transmitting infections, immediate availability and immune tolerance allowing successful transplantation despite human leukocyte antigen disparity. Several studies have shown that the number of cells transplanted is the most important factor for engraftment in CBT, and it limits the wide use of CB in adult patients. New strategies for facilitating engraftment and reducing transplantation-related mortality are ongoing in the field of CBT and include the use of a reduced-intensity conditioning regimen, double-unit CBT, ex vivo expansion of CB, and co-transplantation of CB and mesenchymal stem cells. Recently, the results of two international studies with large sample sizes showed that CB is an acceptable alternative source of hematopoietic stem cells for adult recipients who lack human leukocyte antigen-matched adult donors. Along with the intensive researches, development in banking process of CB will amplify the use of CB and offer the chance for cure in more patients.

• 한국한의학연구원논문집
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• 제14권2호
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• pp.75-80
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• 2008

Background: Qigong is one energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although Qigong-neither itself nor its postulated mechanism of action-are within the paradigm of modern Western medical science. effects on the human body could be possible. Objectives: This study aims to review the bibliography, biological responses and therapeutic effects of Qigong. In the process, this review grasp trends in this field of studies and direct further researches into the right direction. Method: The computerized Korean databases were searched from their respective inception up to January 2008. The search terms used were 'Qi', 'Qigong', 'Doin', 'training', 'bioenergy', 'life nurturing' and random or Korean language terms related to qigong. Several specialized journals were also manually searched for relevant articles. Result: Since the 1990s, Qigong papers in the Korean Literature have been increased. Clinical research studies are among the most control design study. Research subjects are less patient than the general public. The most common treatment disease was Musculo-skeletal disorder. Conclusions: The depth study for the each Qigong is needed. Specifically, I think it should be a clinical studies and qualified research methods for evaluation are needed.

• 대한한의정보학회지
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• 제14권2호
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• pp.11-20
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• 2008

This thesis' "Hwang Jae Nai Kyung(黃帝內經)", it is one among Uihak5kyung(醫學五經), is originally total of 18 volumes, the first half of 9 volumes are Somun(素問) and the latter half of the others are Youngchu(靈樞). Also, it is best of old book and literature integrating process of Chinese's medicine. Somun(素問) is comprehensive and extensive principles from fundamental problem of medical science related etiology, pathology, physiology to such parts of preventive medicine as regimen, recuperation. Moreover, therapeutic part of diagnosis and remedy, practice of acupuncture and moxibustion is recorded to Youngchu(靈樞). In the "Hwang Jae Nai Kyung(黃帝內經)", basic system takes precautions and medical cure for disease by approaching not method analyzing body but fundamentals of oriental medicine observed as organizing relation. For the purpose of mixing up beauty based on Buddhism of books, we shall pursuit notion of beauty treatment to method improving health because period flowing is changed to real well-being culture chasing outside beauty and healthy life. Then, to come close for part of oriental medicine and cosmetology, we shall present method of meridian pathways and understand device for cosmetic improvement by analyzing relation to 12 of pathways, the five viscera and the six entrails & skin.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.752-757
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• 2011

This paper presents vibration characteristics of magnetorheological (MR) elastomer, whose elastic modulus are controllable by an applied magnetic field. By using this property, the material can be applied to vibration absorber, so that the stiffness of the absorber can be changed and actively controlled according to the magnetic flux density. However, the various performances of MR elastomer depends on different magnetically polarization direction and dimension during the manufacturing process. In this paper, in order to obtain the optimal characteristics of MR elastomer, MR elastomers with different types and dimensions are prepared for a series tests. Using this test setup, extent of natural frequency shifted against magnetic field at various excitation frequencies can be measured. Specimens prepared with 3 types which are exposed to magnetic field vertically, horizontally and unexposed during cure. Also, a set of design variables are considered to produce MR elastomers. Through the modal tests of mass structure with MR elastomer, the optimal design as well as the polarization direction of MR elastomer is obtained among the various dimensions and 3 directional types of MR elastomers.

• 한국의사학회지
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• 제19권2호
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• pp.49-66
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• 2006

1) Objective External treatments have various curative effects. So it had been used to cure various patients. But, it has a limited sphere of application in the present South Korea. And treatments of wander doctors had been disregarded by general doctors and the public. But Zhao-Xue-Min(趙學敏) had thought that there are useful treatments in it. So, the "Chuan-Ya(串雅)" had been written by Zhao-Xue-min in 1759. The book had included treatments of wander doctors. Especially, it had included various external treatments. Therefore we would like to bring out it's external treatments theory 2) Conclusions We have researched external treatments of "Chuan-Ya", and then we have arrived at following conclusions. "Chuan-Ya" has 48 sentences that have related to external treatments in internal medicine. And it had recorded fire conducting method(引火法) to explain process of external teratment principle.