생쥐 모델을 이용한 배아의 할구 생검법과 할구가 생검된 배아의 배양시 공배양 효과에 관한 연구: 인간에서의 착상 전 유전진단 기술 개발을 위한 동물실험 모델의 개발

김석현,류범용,지병철,최성미,김희선,방명걸,오선경,서창석,최영민,김정구,문신용,이진용,채희동,김정훈,Kim, S.H.,Ryu, B.Y.,Jee, B.C.,Choi, S.M.,Kim, H.S.,Pang, M.G.,Oh, S.K.,Suh, C.S.,Choi, Y.M.,Kim, J.G.,Moon, S.Y.,Lee, J.Y.,Chae, H.D.,Kim, C.H. 대한생식의학회 1999 Clinical and Experimental Reproductive Medicine Vol.26 No.1

The genetic defects in human gametes and embryos can cause adverse effects on overall reproductive events. Biopsy of embryos for preimplantation genetic diagnosis (PGD) offers a new possibility of having children free of the genetic disease. In addition, advanced embryo culture method may enhance the effectiveness of embryo biopsy for the practical application of PGD. This experimental study was undertaken to evaluate the effects of coculture on the development in vitro of biopsied mouse embryos as a preclinical model for PGD of human embryos. Embryos were obtained after in vitro fertilization (IVF) from F1 hybrid mice (C57BLfemale/CBAmale). Using micromanipulation, 1, 2, 3 or 4 blastomeres of 8-cell stage embryos were aspirated through a hole made in the zona pellucida by zona drilling (ZD) with acidic Tyrode's solution (ATS). After biopsy of blastomeres, embryos were cultured in vitro for 110 hours in Ham's F-10 supplemented with 0.4% BSA or cocultured on the monolayer of Vero cells in the same medium. The frequence of blastocyst formation were recorded, and the embryos beyond blastocyst stage were stained with 10% Giemsa to count the total number of nuclei in each embryo. There was no significant difference in the blastocyst formation between the zona intact control group and the zona drilling (ZD) only, or biopsied groups. The hatching rate of all the treatment groups except 4/8 group was significantly higher than that of control group. In all the treatment groups, there was a significant reduction in the mean cell number of embryos beyond blastocyst stage ($50.2{\pm}14.0$ in control group vs. $41.2{\pm}7.9$ in ZD, $39.3{\pm}8.8$ in 7/8, $29.7{\pm}6.4$ in 6/8, $25.1{\pm}5.7$ in 5/8, and $22.1{\pm}4.3$ in 4/8 groups, p<0.05). When the same treatments were followed by coculture with Vero cells, a similar pattern was seen in the blastocyst formation and the hatching rate. However, in all the treatment groups, there was a significant increase in the mean cell number of embryos beyond blastocyst stage with coculture, compared with the parallel groups without coculture. In the cleavage rate of biopsied blastomeres cultured for 110 hours after IVF, there was no significant difference between coculture and non-coculture groups (87.2% vs. 78.7%). However, the mean cell number of embryos developed from the biopsied blastomeres was significantly higher in coculture group ($11.5{\pm}4.7\;vs.\;5.9{\pm}1.9$, p<0.05). In conclusion, biopsy of mouse embryos after ZD with ATS is a safe and highly efficient method for PGD, and coculture with Vero cells showed a positive effect on the development in vitro of biopsied mouse embryos and blastomeres as a preclinical model for PGD of human embryos.

난자 세포질내 정자 주입술 후 동결보존 배아이식: 고식적 체외수정시술과의 비교 연구

김석현,지병철,정병준,김희선,류범용,방명걸,오선경,손철,서창석,최영민,김정구,문신용,이진용,Kim, S.H.,Jee, B.C.,Jung, B.J.,Kim, H.S.,Ryu, B.Y.,Pang, M.G.,Oh, S.K.,Shon, C.,Suh, C.S.,Choi, Y.M.,Kim, J.G.,Moon, S.Y.,Lee, J.Y. 대한생식의학회 1997 Clinical and Experimental Reproductive Medicine Vol.24 No.3

The objective of this study was to compare retrospectively the survival and pregnancy rates(PR) of cryopresered-thawed embryos obtained from intracytoplasmic sperm injection (ICSI) or conventional in vitro fertilization (IVF). Ninety-six cycles of cryopresered-thawed embryo transfer (ET) were performed in 79 patients from June, 1996 to September, 1997 and grouped as followings: 20 cycles (16 patients) inseminated by ICSI (ICSI Group) and 76 cycles (63 patients) by conventional IVF (IVF Group). Slow-freezing and rapid-thawing protocol was used with 1.5M propanediol (PROH) and 0.1M sucrose as cryoprotectant. All embryos were frozen-thawed at the two pronuclear (2 PN) stage excluding four cycles in which the early cleavage stage embryos were frozen, and allowed to cleave in vitro for one day before ET. The duration from freezing to thawing was comparable in both groups ($mean{\pm}SD$, $112.1{\pm}80.0$ vs. $124.8{\pm}140.1$ days). The age of female ($31.2{\pm}3.4$ vs. $32.6{\pm}3.3$ years) and the endometrial thickness prior to progesterone injection ($9.4{\pm}2.0$ vs. $9.3{\pm}1.8$ mm) were also comparable in both groups. There was no significant difference in the outcomes of cryopreserved-thawed ET between two groups: survival rate ($85.2{\pm}16.1%$ vs. $82.2{\pm}19.7%$), cleavage rate ($96.9{\pm}6.7%$ vs. $94.7{\pm}13.0%$), cumulative embryo score (CES, $54.5{\pm}31.1$ vs. $49.0{\pm}20.0$), preclinical loss rate (5.0% vs. 5.3%), clinical miscarriage rate (0% vs 29.4%), clinical PR per transfer (35.0% vs. 22.4%), implantation rate (9.9% vs. 5.6%), and multifetal PR (42.9% vs. 17.6%). In conclusion, human embryos resulting from ICSI can be cryopreserved-thawed and transferred successfully, and the survival rate and PR are comparable to conventional IVF.

블록체인 기반의 FIDO 범용 인증 시스템

김석현,허세영,조영섭,조상래,김수형,Kim, S.H.,Huh, S.Y.,Cho, Y.S.,Cho, S.R.,Kim, S.H. 한국전자통신연구원 2018 전자통신동향분석 Vol.33 No.1

In this paper, we describe a FIDO universal authentication system based on a Blockchain that can share the user's FIDO authentication information between the application services of multiple domains without the use of a server. In addition we provide a method to query the FIDO authentication information of the user recorded in the Blockchain using only the user's service ID. Therefore, even if the user executes the FIDO registration process only once, the user can use the FIDO authentication service of another application service without repeating an additional FIDO registration procedure, and the service provider can securely share and utilize the FIDO authentication information of the user without the use of a trusted third party, thereby lowering the deployment and maintenance costs of the FIDO server.

판형 상변화 물질 용기의 2상 열교환 현상 연구

김석현,조성우,이채수,Kim, S.H.,Cho, S.W.,Lee, C.S. 대한설비공학회 1996 설비공학 논문집 Vol.8 No.4

This work studies qualitative thermal characteristics of PCM cold storage medium container and its surrounding streams. Experimental parameters are initial PCM temperature and cold water flow rate. A mathematical modeling was establised to estimate temperature distribution and the cooling process. We found that the phase-change temperatures of PCM varies from 6 to $8^{\circ}C$ which is constant for other materials and that the dominant heat transfer resistance is that on the container side taking about 3/4 of the total resistance. The one dimensional mathematical model predicts experimental data quit well.

해양오염퇴적물 정화를 위한 산화공정에서 입자크기에 따른 중금속 제거 가능성

심영섭(Y.S.Sim),김경련(K.R.Kim),최진영(J.Y.Choi),김석현(S.H.Kim) 한국해양환경·에너지학회 2015 한국해양환경·에너지학회 학술대회논문집 Vol.2015 No.5

본 연구에서는 해양오염퇴적물의 정화를 위한 산화공정에서 입자크기에 따른 총 중금속의 제거 정도와 가능성을 평가 하였다. 해양오염퇴적물 정화사업 대상인 N해역의 퇴적물을 채취하여 입도별로 분리한 뒤 과산화수소(H₂O₂, 1, 3, 5 M)와 비이온 계면활성제(Tween-80, 0.05%)를 넣어 반응시간(5, 10, 20, 30, 60, 90, 120 분)에 따른 총 중금속 제거 가능성 확인을 위한 실험실 규모의 실험(Lab-scale test)을 실시하였다. 고농도의 과산화수소의 경우 공정제어가 어려워 1 M이하의 과산화수소가 적합할 것으로 판단되며 입자크기 63 ㎛이상의 경우 1 M의 조건에서도 제거가 가능하였으나 63 ㎛이하의 경우 1 M의 조건에서 제거되지 않아 제거효율을 높일 수 있는 추가적인 공정이나 연구가 필요할 것으로 사료된다. In this study, heavy metals removal of marine sediments was investigated on the basis of particle size distribution using by washing technology in laboratory scale test. Contaminated marine sediments were collected at N area and were divided >63 ㎛, 63 μ㎛~32 ㎛ and > 32 ㎛ fraction. Above mentioned, each fraction of samples were mixed hydrogen peroxide(H₂O₂, 1, 3, 5 M) and non-ionic surfactant(Tween-80, 0.05 %). In this research reaction time was defined as 5, 10, 20, 30, 60, 90, 120 min. 1 M H₂O₂condition was mainly focused in this research in order to achieve easy control of reaction and cost-effectiveness. Higher than 63㎛ fraction was good removal ratio that 4.43~38.91 %. However heavy metals of <63㎛ fraction were not removed at 1 M H₂O₂ condition. Therefore additional process for improve removal efficiency was considered.

빙축열 시스템 시뮬레이션

김석현,Kim, S.H. 대한설비공학회 1994 설비저널 Vol.23 No.3

다태임신에서의 선택적 유산술시 복식 천자와 질식 천자의 비교 연구

김석현,문신용,이진용,Kim, S.H.,Moon, S.Y.,Lee, J.Y. 대한생식의학회 1996 Clinical and Experimental Reproductive Medicine Vol.23 No.1

The number of multifetal pregnancies has increased dramatically as a result of the widespread clinical use of ovulation induction and assisted reproductive technology(ART) in infertile patients. In multifetal pregnancies, the adverse outcome is directly proportional to the number of fetuses within the uterus, primarily because of an increased predisposition to premature delivery. It is extremely difficult to counsel patients about the expected outcome of pregnancies involving three or more fetuses. To increase the chances of delivering infants mature enough to survive without being irreversibly damaged by the sequelae of marked prematurity, selective fetal reduction(SFR) to the smaller number of fetuses should be considered in multifetal pregnancies. From January, 1991 to December, 1992, transabdominal SFR in multifetal pregnancies was performed in 22 patients including 13 triplet, 7 quadruplet, 1 quintuplet and 1 heptuplet pregnancies. Transabdominal SFR using intracardiac KCI injection and aspiration of amniotic fluid was carried out in 8-13 weeks of gestation. After procedure, 20 patients were remained as twin pregnancies, and 2 patients as triplet pregnancies. There have been 11 sets of twin delivery including 2 stillbirths, 2 sets of triplet delivery including 1 stillbirth, and 1 singleton delivery. Six cases were delivered after 37 weeks of gestation, 4 cases in 33 - 37 weeks, and 1 case in 30 weeks. Unfortunately, 3 stillbirths occurred in 20-24 weeks of gestation, and 4 cases were aborted. As 7 losses of pregnanancy including 1 case of septic abortion occurred, the delayed fetal loss rate was 38.9%(7/18) in transabdominal SFR. All babies born after 30 weeks of gestation were healthy, and no fetal anomaly directly related to the procedure was encountered. From July, 1993 to February, 1995, transvaginal SFR was performed in 20 patients including 15 triplet, 4 quadruplet and 1 quintuplet pregnancies. Transvaginal SFR using the same method as transabdominal SFR was carried out in 8-11 weeks of gestation. After procedure, 19 patients were remained as twin pregnancies, and 1 patient as singleton pregnancy. There have been 13 sets of twin delivery including 2 stillbirths, and 1 singleton delivery. Six cases were delivered after 37 weeks of gestation, 5 cases in 36-37 weeks, and 1 case in 30 weeks. Unfortunately, 2 still-births occurred in 20 weeks and 21 weeks of gestation, respectively, and 2 cases were aborted. As 4 losses of pregnancy including 1 case of septic abortion occurred, the delayed fetal loss rate was 25.0%(4/16) in transvaginal SFR. No fetal anomaly directly related to the procedure was encountered. It is suggested that transvaginal SFR could be performed more easily and earlier with the lower fetal loss rate as compared with transabdominal SFR. In conclusion, SFR is a rather safe and ethically justified procedure that may improve the outcome of multifetal pregnancies.

링 구조물의 맥놀이의 선명도와 주기 조절법

김석현(S.H. Kim),C.X. Cui 한국소음진동공학회 2008 한국소음진동공학회 학술대회논문집 Vol.2008 No.11

등가링 모델을 이용한 맥놀이 조절 기법

김석현(S.H. Kim),C.X. Cui 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

In this study, we propose a practical method to control the beat property of a bell type structure using an equivalent ring model. Slight asymmetry in a bell generates the mode pair and the interaction of the mode pair makes beating in sound and vibration. A slightly asymmetric ring as a simplified bell, is investigated for the mode split and beat property. An equivalent ring is determined as the assemblage of a symmetric ring and imperfect point masses. The equivalent ring satisfies the same mode condition as that of the original asymmetric ring. With the equivalent ring, the additional mass effect and thickness decrement effect are examined by theory, measurement and the finite element analysis.

맥놀이의 등가 링 이론에 관한 실험적 검토

김석현(S.H.Kim),C.X.Cui,박한길(H.G.Park) 한국소음진동공학회 2007 한국소음진동공학회 학술대회논문집 Vol.2007 No.11