의료용 저출력 LED 발진기의 광 특성 평가

천민우,박용필 동신대학교 2006 論文集 Vol.16 No.-

This paper performed the basic study for developing the Photodynamic Therapy Equipment for medical treatment. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on. Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. As a result, Light Emitting Diode Module was made for the optimization of irradiation condition. And we confirmed the current change according to increase of the level of Light Emitting Diode Module.

BSCCO 시스템에서 초전도상의 특성

박용필,양승호,천민우 동신대학교 2005 論文集 Vol.15 No.-

BSCCO(Bi_(2)Sr_(2)Ca_(n-1)Cu_(n)O_(x)) 초전도 상을 이온 빔 스퍼터와 단일 타겟 DC-magnetron 스퍼터를 사용하여 제작하였다. 상형성은 n=2-3, 3-4 그리고 4-5 사이에서 이루어졌다. 스퍼터링 시 분위기 가스로 산소를 주입 하였고 제작된 박막의 상의 몰 비를 XRD를 이용하여 분석하였다. 각 상의 몰 비를 이용하여 초전도박막의 특성을 변화시킬 수 있음을 알았다. 또한, 각 상을 AFM과 SEM을 사용하여 박막의 표면을 관찰하여 표면의 불순물 상태를 알 수 있었다. BSCCO(Bi_(2)Sr_(2)Ca_(n-1)Cu_(n)O_(x)) superconducting phase were fabricated by an ion beam sputtering and single target dc-magnetron sputtering. Phase intergrowth among n=2-3, 3-4 and 4-5 phases was observed. The molar fraction of each phase in the mixed crystal of the deposited films was determined by X-ray diffraction analyses and investigated as a function of O_(2) gas pressure during sputtering. We investigated the changes of the superconducting properties by molar fraction of each phase. Also, the thin film surface observation was carried out by AFM. According to the result observing the surface of the thin film with SEM, even in case that the formed phase and the composition of the thin film agree, it can be known that there are a number of the precipitates on the surface.

Spatio-temporal Expression and Regulation of Dermatopontin in the Early Pregnant Mouse Uterus

Yong-Pil Cheon,Hyun Sook Kim 한국분자세포생물학회 2006 Molecules and cells Vol.22 No.3

PAF Regulate Blastocyst Development to Hatching Stage through PKC Activity in the Mouse

Cheon Yong-Pil The Korean Society of Animal Reproduction 2006 Reproductive & developmental biology Vol.30 No.2

The developmental regulation of the preimplantation mammalian embryos is a fundamental step for preparing the implantation and it may be regulated by several autocrine and paracrine factors including platelet-activating factor. PAF improved the embryonic survival and implantation but its role during blastocyst development is still largely unknown. In this study, the effects and the possible pathway of PAF on developmental regulation of blastocyst to hatching stage were investigated. Developmental pattern in hatching embryo was a concentration-response curve showing maximal activity at 1 nM PAF, with decreasing activity at higher concentrations. $50{\mu}M$ 1-(5-isoquinolimnesulfonyl)-2-methylpiperazinme dihydrochloride (H-7), a PKC inhibitor, inhibited the progression of blastocyst to hatching embryo. In addition H-7 blocked the PAF effects on the blastocyst development. Besides tetradecanoylphorbol acetate (TPA), a PKC activator stimulated development of blastocyst to the hatching stage. These finding revealed that PAF support the blastocyst development to the hatching embryo. Also it is suggested that PAF action pathways in hatching supporting include the PKC signaling pathway.

PAF Regulate Blastocyst Development to Hatching Stage through PKC Activity in the Mouse

Yong-Pil Cheon 사단법인 한국동물생명공학회 2006 Reproductive & developmental biology Vol.30 No.2

The developmental regulation of the preimplantation mammalian embryos is a fundamental step for preparing the implantation and it may be regulated by several autocrine and paracrine factors including platelet-activating factor. PAF improved the embryonic survival and implantation but its role during blastocyst development is still largely unknown. In this study, the effects and the possible pathway of PAF on developmental regulation of blastocyst to hatching stage were investigated. Developmental pattern in hatching embryo was a concentration-response curve showing maximal activity at 1 nM PAF, with decreasing activity at higher concentrations. 50 μM 1-(5-isoquinolimnesulfonyl)-2-methylpiperazinme dihydrochloride (H-7), a PKC inhibitor, inhibited the progression of blastocyst to hatching embryo. In addition H-7 blocked the PAF effects on the blastocyst development. Besides tetradecanoylphorbol acetate (TPA), a PKC activator stimulated development of blastocyst to the hatching stage. These finding revealed that PAF support the blastocyst development to the hatching embryo. Also it is suggested that PAF action pathways in hatching supporting include the PKC signaling pathway.

Regulation and 3 dimensional culture of tertiary follicle growth

Cheon, Yong-Pil The Korean Society for Reproductive Medicine 2012 Clinical and Experimental Reproductive Medicine Vol.39 No.3

It has been revealed that multiple cohorts of tertiary follicles develop during some animal estrous cycle and the human menstrual cycle. To reach developmental competence, oocytes need the support of somatic cells. During embryogenesis, the primordial germ cells appear, travel to the gonadal rudiments, and form follicles. The female germ cells develop within the somatic cells of the ovary, granulosa cells, and theca cells. How the oocyte and follicle cells support each other has been seriously studied. The latest technologies in genes and proteins and genetic engineering have allowed us to collect a great deal of information about folliculogenesis. For example, a few web pages (http://www.ncbi.nlm. nih.gov; http://mrg.genetics.washington.edu) provide access to databases of genomes, sequences of transcriptomes, and various tools for analyzing and discovering genes important in ovarian development. Formation of the antrum (tertiary follicle) is the final phase of folliculogenesis and the transition from intraovarian to extraovian regulation. This final step coordinates with the hypothalamic-pituitary-ovarian axis. On the other hand, currently, follicle physiology is under intense investigation, as little is known about how to overcome women's ovarian problems or how to develop competent oocytes from in vitro follicle culture or transplantation. In this review, some of the known roles of hormones and some of the genes involved in tertiary follicle growth and the general characteristics of tertiary follicles are summarized. In addition, in vitro culture of tertiary follicles is also discussed as a study model and an assisted reproductive technology model.

Regulation of pregastrulation stage embryonic developmental potency in mammals

Yong-Pil Cheon(전용필) 한국실험동물학회 2020 한국실험동물학회 학술발표대회 논문집 Vol.2020 No.7

Regulation of the Preim plantation Stage Embryonic D evelopment

Yong-Pil Cheon 한국동물생명공학회(구 한국동물번식학회) 2005 Reproductive & Developmental Biology(Supplement) Vol.29 No.2s

Impact of glycosylation on the unimpaired functions of the sperm

Cheon, Yong-Pil,Kim, Chung-Hoon The Korean Society for Reproductive Medicine 2015 Clinical and Experimental Reproductive Medicine Vol.42 No.3

One of the key factors of early development is the specification of competence between the oocyte and the sperm, which occurs during gametogenesis. However, the starting point, growth, and maturation for acquiring competence during spermatogenesis and oogenesis in mammals are very different. Spermatogenesis includes spermiogenesis, but such a metamorphosis is not observed during oogenesis. Glycosylation, a ubiquitous modification, is a preliminary requisite for distribution of the structural and functional components of spermatids for metamorphosis. In addition, glycosylation using epididymal or female genital secretory glycans is an important process for the sperm maturation, the acquisition of the potential for fertilization, and the acceleration of early embryo development. However, nonemzymatic unexpected covalent bonding of a carbohydrate and malglycosylation can result in falling fertility rates as shown in the diabetic male. So far, glycosylation during spermatogenesis and the dynamics of the plasma membrane in the process of capacitation and fertilization have been evaluated, and a powerful role of glycosylation in spermatogenesis and early development is also suggested by structural bioinformatics, functional genomics, and functional proteomics. Further understanding of glycosylation is needed to provide a better understanding of fertilization and embryo development and for the development of new diagnostic and therapeutic tools for infertility.

YY1 and CP2c in Unidirectional Spermatogenesis and Stemness

Cheon, Yong-Pil,Choi, Donchan,Lee, Sung-Ho,Kim, Chul Geun The Korean Society of Developmental Biology 2020 발생과 생식 Vol.24 No.4

Spermatogonial stem cells (SSCs) have stemness characteristics, including germ cell-specific imprints that allow them to form gametes. Spermatogenesis involves changes in gene expression such as a transition from expression of somatic to germ cell-specific genes, global repression of gene expression, meiotic sex chromosome inactivation, highly condensed packing of the nucleus with protamines, and morphogenesis. These step-by-step processes finally generate spermatozoa that are fertilization competent. Dynamic epigenetic modifications also confer totipotency to germ cells after fertilization. Primordial germ cells (PGCs) in embryos do not enter meiosis, remain in the proliferative stage, and are referred to as gonocytes, before entering quiescence. Gonocytes develop into SSCs at about 6 days after birth in rodents. Although chromatin structural modification by Polycomb is essential for gene silencing in mammals, and epigenetic changes are critical in spermatogenesis, a comprehensive understanding of transcriptional regulation is lacking. Recently, we evaluated the expression profiles of Yin Yang 1 (YY1) and CP2c in the gonads of E14.5 and 12-week-old mice. YY1 localizes at the nucleus and/or cytoplasm at specific stages of spermatogenesis, possibly by interaction with CP2c and YY1-interacting transcription factor. In the present article, we discuss the possible roles of YY1 and CP2c in spermatogenesis and stemness based on our results and a review of the relevant literature.