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

G Protein Mediated Hatching Regulation in the Mouse Embryo

Cheon Yong-Pil 한국발생생물학회 2012 발생과 생식 Vol.16 No.1

Hatching occurred in the time dependent manners and strictly controlled. Although, the hatching processes are under the control of muti-embryotrophic factors and the expressed G proteins of cell generate integrated activation, the knowledge which GPCRs are expressed during hatching stage embryos are very limited. In the present study, which G proteins are involved was examined during blastocyst development to the hatching stage. The early-, expanded-, and lobe-stage blastocysts were treated with various activators and H series inhibitors, and examined developmental patterns. Pertusis toxin (PTX) improved the hatching rate of the early-stage blastocyst and lobe-formed embryos. Cholera toxin (CTX) suppressed the hatching of the early-stage blastocyst and expanded embryos. The effects of toxins on hatching and embryo development were changed by the H7 and H8. These results mean that PTX mediated GPCRs activation is signaling generator in the nick or pore formation in the ZP. In addition, PTX mediated GPCR activation induces the locomotion of trophectoderm for the escaping. CTX mediate GPCRs activation is the cause of suppression of hatching processes. Based on these data, it is suggested that various GPCRs are expressed in the periimplantation stage embryos and the integration of the multiple signals decoding of various signals in a spatial and temporal manner regulate the hatching process.

Regulation of pregastrulation stage embryonic developmental potency in mammals

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

Guanosine Regulates Germinal Vesicle Breakdown (GVBD) in Mouse Oocytes

Cheon Yong-Pil 한국동물생명공학회(구 한국동물번식학회) 2004 Reproductive & developmental biology Vol.28 No.4

Maturation of oocytes is maintained by complex procedures along with follicular genesis and is a critical step for embryonic development. Purine known as an oocyte maturation regulator is present in follicular fluid. In this study, the roles of guanosine as a strong inhibitor of GVBD and a modulator of cyclic GMP concentration in ooyctes were revealed. Denuded immature oocytes were treated with guanosine, and the maturation rates and cGMP concentration of oocytes were measured. GVBD was blocked in a concentration dependent manner by guanosine, but this effect was reversible. However, GVBD was lagged yet not significant by adenosine. Both guanosine and adenosine modified cGMP concentration in oocytes. The characteristic of the guanosine-treated oocyte was significantly higher cGMP compared with the adenosine-treated oocyes at initial time of the maturation. Based these results, guanosine may be a strong and reversible GVBD inhibitor. Although the precise mechanism of guanosine presently is unclear, the results suggest that guanosine may lead the accumulation of cGMP in oocyte cytoplasm, which in turn suppresses GVBD.

Expression Profiles of Secretory Leucocyte Protease Inhibitor, MMP9, and Neutrophil Elastase in the Mouse Uterus

Cheon Yong-Pil 한국발생생물학회 2010 발생과 생식 Vol.14 No.3

The tremendous changes of uterine endometrium are observed during early pregnancy and protease and their inhibitors are involved in regulation of cell proliferation and remodeling of the tissues through remodeling the extracellular matrix (ECM). Some of the proteases and protease inhibitors have been suspected to a factor in endometrial changes but many parts of their expression profiles and the physiological roles are not uncovered. To evaluate the functional roles of them, in this study the expression profiles of proteases and protease inhibitors were analyzed using real-time quantitative PCR analysis. Mmp9 (matrix metalloproteinase 9) mRNA levels peaked on day 4 at the time of implantation. On the other hand, Ela2 (neutrophil elastase, NE) mRNA levels were peaked on day 2 of pregnancy. Its expression were decreased until day 4 of pregnancy but increased rapidly until day 7 of pregnancy and decreased again. NE inhibitor Slpi (secretory leukocyte protease inhibitor, SLPI) mRNA levels were related with the implantation stage and with the levels of Ela2. At the time of implantation the expression levels of Slpi mRNA were about 5 times higher than the Ela2 mRNA in the uterus. In the implantation stage embryos, Mmp9 specific mRNA was only detected at the blastocyst. On the other hand, the expression level of SLPI was higher than that of the Ela2 mRNA at blastocyst and 4.5 day p.c. embryos. Based on these results it is suggested that MMP9, SLPI, and NE have important physiological role in embryo implantation both in uterus and embryos.

Androgen in the Uterus: A Compensator of Estrogen and Progesterone

Cheon Yong-Pil,Lee Dong-Mok,Chun Tea-Hoon,Lee Ki-Ho,Choi In-Ho 한국발생생물학회 2009 발생과 생식 Vol.13 No.3

Pivotal roles of steroid hormones in uterine endometrial function are well established from the mouse models carrying the null mutation of their receptors. Literally androgen belongs to male but interestingly it also detected in female. The fluctuations of androgen levels are observed during reproductive cycle and pregnancy, and the functional androgen receptor is expressed in reproductive organs including uterus. Using high throughput methodology, the downstream genes of androgen have been isolated and revealed correlations between other steroid hormones. In androgen-deficient mice, uterine responses to exogenous gonadotropins are impaired and the number of pups per litter is reduced dramatically. As expected androgen has important role in decidual differentiation through AR. It regulates specific gene network during those cellular responses. Recently we examined the effects of steroid hormonal complex containing high level of androgen. Interestingly, on the contrary to the androgen-alone administration, the hormonal complex did not disturb the decidual reaction and the pubs did not show any morphological abnormality. It is suspected that the complexity of communication between other steroid hormone and their receptors are the reasons. In summary, androgen exists in female blood and it suggests the importance of androgen in female reproduction. However, the complex interactions with other hormones are not fully understood compared with estrogen and progesterone. The further studies to evaluate the possible role of androgen are needed and important to provide the in vivo rational for the prevention of associated pregnancy complications and help human's health.

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.

Assessment of Adipocyte Differentiation and Maturation-related Gene Expression in the Epididymal Fat of Estrogen Receptor α Knockout (ERαKO) Mouse during Postnatal Development Period

Cheon, Yong-Pil,Ko, CheMyong,Lee, Ki-Ho The Korean Society of Developmental Biology 2020 발생과 생식 Vol.24 No.4

The absence of functional estrogen receptor α (Esr1) results in an overgrowth of the epididymal fat, as observed in estrogen receptor α knockout (ERαKO) mouse. The present research was aimed to evaluate expression of various molecules associated with adipocyte differentiation and maturation in the epididymal fat of ERαKO mouse at several postnatal ages by using quantitative real-time polymerase chain reaction. The highest transcript levels of all molecules were detected at 12 months of postnatal age, except leptin which the mRNA level was increased at 5 months of age and was unchanged until 12 months of age. The expression levels of CCAAT enhancer binding protein (Cebp) alpha, androgen receptor, and lipoprotein lipase were decreased at 5 months of age but increased at about 8 months of age. The mRNA levels of Cebp gamma and sterol regulatory element binding transcription factor 1 remained steady until 8 months of age. Continuous increases of transcript levels during postnatal period were found in Cebp beta, estrogen receptor (ER) beta, fatty acid binding protein 4, and delta like non-canonical Notch ligand 1. The increases of peroxisome proliferator-activated receptor gamma and adiponectin mRNA levels were detected as early as 8 months of age. The levels of fatty acid synthase and resistin transcript at 5 and 8 months of age were lower than that at 2 months of age. These findings show the aberrant expression patterns of genes related to adipocyte differentiation and maturation in the postnatal epididymal fat pad by the disruption of ER alpha function.