신선 고환조직 정자와 냉동보존-융해 고환조직 정자를 이용한 난자세포질내 정자주입술 결과의 비교 연구

최영식,최영민,김수웅,백재승,지병철,구승엽,서창석,김석현,김정구,문신용,Choi, Young-Sik,Choi, Young-Min,Kim, Soo-Woong,Paick, Jae-Seung,Jee, Byung-Chul,Ku, Seung-Yup,Suh, Chang-Suk,Kim, Seok-Hyun,Kim, Jung-Gu,Moon, Shin-Yong 대한생식의학회 2008 Clinical and Experimental Reproductive Medicine Vol.35 No.2

목 적: 무정자증 불임부부에서 신선 (fresh) 고환정자 (testicular spermatozoa)와 냉동보존-융해(cryopreserved-thawed) 고환정자를 사용한 난자세포질내 정자주입술 (intracytoplasmic sperm injection, ICSI)의 결과를 비교하고자 하였다. 연구방법: 신선 고환정자 및 냉동보존-융해 고환정자를 사용하여 ICSI 시술을 시행하기로 계획된 총 109주기 (66명)를 대상으로 하였고 신선 고환정자를 사용하기로 계획한 군 (신선 고환정자군, fresh group)에는 92주기 (61명)이 포함되었고 냉동보존-융해 고환정자를 사용하기로 계획한 군 (냉동보존-융해 고환정자군, cryopreserved-thawed group)에는 17주기 (13명)가 포함되었다. 양 군간에 수정률, 착상률, 임신률, 유산률 등 ICSI 시술의 결과들을 비교하였고 통계학적 분석은 Mann-Whitney U 검정 및 Fisher의 정확한 검정을 적절하게 사용하였다. 결 과: 신선 고환정자를 사용하여 ICSI 시술을 시행하기로 계획된 총 92주기 중 9주기에서 고환정자를 추출할 수 없어 시술 주기가 취소되었다. 냉동보존-융해 고환정자군과 비교하여 신선 고환정자군에서 수정률이 높은 경향을 보였고 ($58.0{\pm}27.8%$ vs. $45.9{\pm}25.0%$, p=0.076) 양질의 배아 수는 통계적으로 유의하게 높았다 ($0.9{\pm}1.2$ vs. $0.2{\pm}0.5$, p=0.002). 그러나 임상적 임신율, 착상률, 유산율은 양 군간에 통계적으로 유의한 차이가 없었다. 결 론: ICSI 시술을 위하여 냉동보존-융해 고환정자를 사용하는 경우 수정률 및 배아의 질이 감소하지만 임신율, 착상률, 유산율에는 영향을 미치지 않는 것으로 사료된다. 또한, ICSI 시술이전에 고환정자를 확보하고 냉동보존-융해 고환정자를 사용한다면 난자채취 당일 정자를 확보하지 못하여 주기를 취소하는 경우나 여성배우자의 불필요한 과배란유도를 줄일 수 있으며 반복적인 고환정자추출술로 인한 고환기능의 손상을 줄일 수 있는 유용한 방법으로 사료된다. Objective: To compare the outcomes of intracytoplasmic sperm injection (ICSI) with fresh and cryopreserved-thawed testicular spermatozoa in patients with azoospermia. Methods: One hundred and nine cycles (66 couples) where ICSI was planned with fresh or cryopreserved-thawed testicular spermatozoa were included in this study; Ninety two cycles (61 couples) with fresh testicular spermatozoa (fresh group) and seventeen cycles (13 couples) with cryopreserved-thawed testicular spermatozoa (cryopreserved-thawed group). We compared ICSI outcomes such as fertilization rate, implantation rate, pregnancy rate and miscarriage rate, which were statistically analyzed using Mann-Whitney U test or Fisher's exact test, where appropriate. Results: In 9 out of the 92 cycles where ICSI was planned with fresh testicular spermatozoa, testicular spermatozoa could not be retrieved. Fertilization rate tended to be higher in the fresh group than in the cryopreserved-thawed group ($58.0{\pm}27.8%$ vs. $45.9{\pm}25.0%$, p=0.076). The number of high quality embryos was significantly higher in the fresh group ($0.9{\pm}1.2$ vs. $0.2{\pm}0.5$, p=0.002). However, there were no significant differences in clinical pregnancy rate, implantation rate and miscarriage rate between the two groups. Conclusion: The results of this study suggest that although the use of cryopreserved-thawed testicular sperm for ICSI in patients with azoospermia may reduce fertilization capacity and embryo quality, it may not affect pregnancy rate, implantation rate and miscarriage rate. If testicular sperm can be obtained before ICSI procedure, the use of cryopreserved-thawed testicular sperm may also avoid unnecessary controlled ovarian hyperstimulation and cancellation of oocyte retrieval when spermatozoa cannot be retrieved as well as damage on testicular function by repeated TESE.

황 함유 석탄회 콘크리트 몰탈에서의 강관의 부식

최영식,강탁 ( Young Sik Choi,Tak Kang ) 한국부식방식학회 1994 Corrosion Science and Technology Vol.23 No.1

강원지역에서의 첩포시험 성적

최영식,방동식 ( Young Sik Choi,Dong Sik Bang ) 대한피부과학회 1990 대한피부과학회지 Vol.28 No.5

전해법에 의한 퍼말로이 박막의 제조

최영식(Young-Sik Choi),김성은(Seong-Eun Kim),강탁(Tak Kang),손헌준(Hun-Joon Sohn) 한국표면공학회 1994 한국표면공학회지 Vol.27 No.4

인공기후실내의 바닥온도 변화에 의한 인체의 생리적 반응

최영식(Young-Sik Choi) 한국산업융합학회 1998 한국산업융합학회 논문집 Vol.1 No.1

The purpose of this study is to clarify the floor temperature on the human body and to estimate thermal comfort zone in a heated room. In order to evaluate the effects of floor heating, a series of experiments were carried out using Korean subjects. The following experiments were conducted: 1) to obtain the effective radiation area and configuration factors of the person in the sitting posture on a floor to get the mean radiant temperature, 2) to measure contact 떠 area of the person to the floor to calculate conduction heat rate, 3) to measure convective heat transfer coefficient of the body and 4) to know the thermal comfort zone of indoor environment heated by ON-DOL. Subjects were exposed to the following conditions<br/> combinations of air temperature 20℃, 22.5℃, 25℃, and floor temperature 20℃, 22.5℃, 25℃, 27.5℃, 3O℃, 32.5℃, 35℃, 37.5℃, 40℃ under still air and 50% relative humidity in the controllable artificial climate chamber. To evaluate the effect of heat conduction between the body and a floor modified mean skin temperature was defined. Weighting coefficient to calculate mean skin temperature were modified with the contacted area. The experiments revealed a positive correlation between the modified operative temperature and the modified mean skin temperature. The modified mean skin temperature can indicate the effect of heat conduction between body and a floor surface.<br/> <br/>

자연환경상태에서 인공석굴법당의 실내기후조절에 관한 연구

최영식(Young-Sik Choi),조영화(Young-Wha Cho) 한국산업융합학회 1999 한국산업융합학회 논문집 Vol.2 No.1

It is very important that we try to keep our traditional historical assets in the original form for a long time. Artificial grotto has a very long and old history of about 1250 years in Korea. Yet, for the past several years there are many factors ruinning this historical treasure. Recently, specialist are new scientifically examining artificial grotto and evaluating its current condition. If you only judge these historical assets from the exterior structural environmental approach your scientific conclusion will not be complete. No one has studied artificial grotto from the viewpoint of indoor climate environmental. Therefore, I have surveyed and prepared a report of investigation as well as countermeasure so to understand the impact of indoor climate environmental on artificial grotto. The purpose of this paper is to first survey the existing research data based on exterior structural environment. Secondly, closely evaluate the new data of artificial grotto from the viewpoint of indoor environmental control by a natural climate phenomenon in Korea.<br/>

MW급 직접구동형 풍력터빈시스템을 위한 영구자석 동기발전기의 게인 스케쥴링 속도제어기에 대한 연구

최영식(Young-Sik Choi),유동녕(Dong-Young Yu),최한호(Han Ho Choi),정진우(Jin-Woo Jung) 한국조명·전기설비학회 2011 조명·전기설비학회논문지 Vol.25 No.8

This paper presents a new gain scheduling speed controller of permanent magnet synchronous generators(PMSG) for MW-class direct-driven wind turbine systems. The proposed gain scheduling speed controller performs the speed tracking at more than one operating point, and the first-order torque observer estimates the turbine torque which is needed to precisely control the speed of PMSG. The proposed speed controller verifies that the PMSG can successfully follow the reference speed which is determined via the maximum power point tracking(MPPT) control and pitch control under turbulent wind conditions. The proposed speed control algorithm is simulated using Simulink and its performance is confirmed through comparison with the results by PI control method.

클러스터링을 이용한 색상 기반 영상 검색

최영식(Young-sik Choi),백규태(Gyu-tae Baek),김대원(Dae-won Kim) 한국정보과학회 1998 한국정보과학회 학술발표논문집 Vol.1998 No.2

The Feasibility of Cathepsin B Level in Preoperatively Screening Patients with Thyroid Cancer and Nodular Hyperplasia

Young Sik Choi(최영식),Young Ok Kim(김영옥),Woomi Kim(김우미) 한국생명과학회 2009 생명과학회지 Vol.19 No.11

혈장 cathepsin B 활성도 측정이 갑상선암 및 결절성 증식증의 수술 전 진단에 도움이 되는지를 알아보고자 분화갑상선암 32례, 결절성 증식증 7례, 대조군 5례의 혈장 cathepsin B 발현양상을 대조군과 함께 관찰하였다. 수술시 제거된 여포선암의 암조직, 결절성 증식증 조직의 cathepsin B 발현을 정상 조직과 비교하였다. 혈장 Cathepsin B 활성도는 정상 대조군에서 168.94±15.10 (×10?², mU), 결절성 증식증에서 255.45±95.68 (×10?², mU), 악성종양에서 284.87±79.32 (×10?², mU)로써 악성종양군과 결절성 증식증군에서 cathepsin B 발현이 정상 대조군보다 비교적 높게 나타났다(p<0.05). 혈장 cathepsin B의 정량적 비교를 위한 immunoassay결과에서도 결절성 증식증군(17.64±7.49 ng/㎖)과 악성종양군(15.50±7.86 ng/㎖)에서 정상대조군(4.85±0.61 ng/㎖)보다 높은 수치를 나타내었다(p<0.05). 결절성 증식증 및 악성종양군의 조직 내 cathepsin B mRNA발현이 정상 조직에서보다 높게 나타났다. 따라서 혈장 cathepsin B는 갑상선세포의 비정상적인 증식시에 증가됨을 알 수 있으며, 갑상선암 혹은 결절성 증식증을 스크리닝하는데 이용될 수 있을 것으로 사료된다. To evaluate the feasibility of cathepsin-B levels in preoperatively screening patients with thyroid cancer, we assigned these patients to either the thyroid cancer group (n=32) or the nodular hyperplasia group (n=7). Five healthy volunteers served as controls (n=5). We quantified cathepsin-B expressions in cancerous lesions with follicular carcinoma and hyperplastic lesions with nodular hyperplasia, and compared the degrees to those of normal thyroid tissue, which was obtained from matched contralateral lobe. The activity of serum cathepsin B was significantly higher in patients with thyroid carcinoma (284.87±79.32, ×10?² mU) and those with nodular hyperplasia (255.45±95.68, ×10?² mU) than compared to normal control (168.94±15.10, ×10?² mU) (p<0.05). Based on the results of immunoassay, the concentrations of cathepsin B in the thyroid cancer group (15.50±7.86 ng/ml) and the nodular hyperplasia group (17.64±7.49 ng/㎖) were higher than those of the control group (4.85±0.61 ng/㎖). The degree of cathepsin-B mRNA expression was significantly higher in cancerous or hyperplastic lesions than normal thyroid tissues from matched contralateral lobe with follicular carcinoma or non-neoplastic thyroid disease. Our results indicate that the activity of serum cathepsin B is a useful indicator in screening patients with nodular hyperplasia or neoplastic thyroid disease and it may be involved in the abnormal proliferation of cells.

A Study on the Evaluation Methods of Indoor Thermal Environment in Office Building

최영식(Young-Sik Choi) 한국산업융합학회 2003 한국산업융합학회 논문집 Vol.6 No.4

1. The objective of this paper is to investigate the indoor environment from the viewpoint of interaction between physical environment and the human responses.<br/> 2. A continuous measurement has been carried out for 1 year and distribution of variables have been measured for 1 day.<br/> 3. The attitude of workers was investigated by a questionnaire.<br/> 4. As the result, average luminance represented more than 800-1800 lx in the office, in contrast with less than 1000 lx in the encourage luminance of an office.<br/> 5. There was a significant difference of the occupants' response to the light environment between the neighboring environments.<br/> 6. Measured thermal conditions are on the edge of the ASHRAE comfort envelope in summer, and in the neighborhood of the lower dry limit of the envelope in spring.