유동가시화를 이용한 플랩을 갖는 2차원 날개 단면의 유동 특성에 관한 고찰

이경우,조대환,최민선 木浦海洋大學校 2001 論文集 Vol.9 No.2

용혈성 요독 증후근 4례

김두권,조성민,이동석,최성민,하경임 동국대학교 경주대학 1997 東國論集 Vol.16 No.1

용혈성 요독 증후군은 미세혈관성 용혈성 빈혈과 혈소판 감소증 및 급성 신부전을 특징으로 하는 질환으로 정확한 원인은 아직 밝혀지지 않고 있으며 발병기전에서 가장 중요한 것은 신미세혈관의 내피세포의 손상으로 알려져 있다. 이 질환은 1955년 Gasser등^1)에 의하여 처음 보고된 후 서구에서는 소아 급성 신부전의 주된 원인으로 알려져 있은, 국내에서는 1972년 이등^2)이 처음 보고한 이래 매우 드물게 1례씩 증례보고되었으나 최근에는 수례가 보고되는 등 증가추세에 있는 질환이다^3∼11). 저자들은 용혈성 요독 증후군으로 1세 여야에서 지주막하 출혈이 동반된 경우와 10세 여아에서 심한 신부전증으로 복막투석 및 보조요법으로 치료된 경우, 2개월된 남아에서 고나트륨혈증이 동반된 경우 및 14개월된 여아에서 경한 임상경과를 취한 증례를 포함한 4례를 치험하였기에 이를 문헌고찰과 함께 보고하는 바이다. The hemolytic uremic syndrome is a clinical state characterized by microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. The etiology varies and in the majority the cause remained unknowed. Whatever the cause, the end result is extensive endothelial injury of the renal microvasculature. We experience 4 cases of hemolytic uremic syndrome. Case 1 was accompanied with subarachnoid hemorrhage in a year of age, female. Case 2 with severe acute renal failure, which was treated with peritonial dialysis, dypiridamole and aspirin in 10 years of age, female. Case 3 with severe hypernatremia in 2 months of age, male. Case 4 had mild clinical manifestation in 14 months of age, female. The age at presentation ranged from 2 month to 10years. All cases were improved completely without any complication. The review of the literature was made briefly.

한국형 인공심장에 대한 동물실험(AnyHeart™)

선경,손호성,이성호,신재승,이혜원,김승철,원용순,이경갑,정종태,김종원,노양래,이혁수,민병구 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.2

말기심부전증의 새로운 치료대안으로 제시되는 한국형 인공심장(AnyHeartTM)의 효용성과 안정성을 평가하기 위하여 동물실험을 실시하였다. 지난 2년간 고려대학교 안암병원과 제주대학교 동물병원에서는 총 28마리(송아지 18, 면양 4, 실험견 3, 말 2, 산양 1마리)의 다양한 동물에서 한국형 인공심장 이식실험이 실시되었으며, 좌심보조장치로 적용한 1예와 체외휴대형으로 적용한 각 1예를 제외하고 모두 심장보존형 인공심장(이식형 양심보조장치)의 형태로 완전 이식하였다. 수술방법은 주로 우측개흉법을 (Korea University Technique)을 사용하였다. 펌프 박출량은 최대 6 L/min로 평균 3-3.5 L/min를 유지되었으며, Fitting test 4례와 초기 적응과정의 2마리를 제외하고 모두 수술에서 회복되었다. 최장 관찰기간은 37일로 합병증 없이 건강한 상태에서 기초자료 확보를 위해 관찰을 임의종료하였다. 모든 생존동물에서 기계장치와 관련된 부작용은 발견되지 않았고, 임상적으로 나타나는 혈전전색 소견이나 간기능, 신기능, plasma hemoglobin, fibrinogen 등에 이상은 없었다. 적절하게 조기부검이 이루어진 경우에는 인공심장 내부에 혈전이 발견되지 않았고, 간/콩팥/비장 등의 중요장기에 병리검사에서도 전색소견은 발견되지 않았다. 결론으로, 한국형 인공심장은 생체 내에 이식하였을 때 안정적이며 기능이 우수한 것을 알 수 있었다. 한국형 인공심장은 현 상태에서 임상에 적용할 수 있다고 판단되며, 가까운 시일 내에 인체 내 안정성와 유효성에 대한 평가가 가능할 것으로 기대한다. Korean artificial heart (AnyHeartTM) is a new vision in the management of end stage heart failure. We performed the animal experiments to evaluate the performance and safety of AnyHeart. For last 2 years, 28 various animals (cattle 18, sheep 4, canine 3, goat 1) underwent AnyHeart implantation at Korea University Medical Center and Cheju University Animal Hospital. AnyHeart was applied as an implantable BVAD except a case of implantable LVAD or wearable BVAD. A standard technique of implantation was a right thoracotomy approach (Korea University Technique). The pump output was 6 L/min in maximum and 3-3.5 L/min in average. Other than 4 cases of fitting tests and 2 in the early learning period, all animals were recovered from the operation. The longest observation was made until 37th postoperative day, and the observation was terminated to get a control data while the animal was healthy without complications. All survivors were free from device-related morbidity, and there were no evidence of clinically significant thromboembolic episode, liver functions, renla function, plasma hemoglobin, fibrinogen abnormalities. Appropriate autopsy did not show thrombus in the device or embolism in the organs. Conclusively, AnyHeart has been proved efficient and safe during in-vive implantation. The authors believe that AnyHeart can be applied to clinical situations at the moment and expect to perform a clinical trial to test safety and efficacy in the human body within near future.

Current status of assisted reproductive technology in Korea, 2010

Lee, Gyoung Hoon,Song, Hyun Jin,Lee, Kyu Sup,Choi, Young Min The Korean Society for Reproductive Medicine 2015 Clinical and Experimental Reproductive Medicine Vol.42 No.1

Objective: Great advances have been made in the field of assisted reproductive technology (ART) since the first in vitro fertilization (IVF) baby was born in Korea. This study was designed to report on the current status of ART therapy in South Korea between January 1 and December 31 of 2010. Methods: A revised survey, originally developed by the International Committee Monitoring Assisted Reproductive Technologies, was sent to all available ART centers via email in 2013. Fresh embryo transfer (FET) cases were categorized into standard IVF or intracytoplasmic sperm injections. These cases, the thawing embryo transfer (TET) cases, and other related procedures were surveyed. Results: Data from 30,785 ART procedures were provided by 78 clinics. Of the 28,200 cycles in which oocytes were retrieved, 92.2% of these cycles were completely transferred. In addition, 8,075 cycles were confirmed to be clinical pregnancies in the FET cycles, which represent a pregnancy rate of 28.6% per oocyte pick-up and 31.1% per embryo transfer. The most common number of embryos transferred in the FET was three embryos (37.3%) followed by two embryos (36.3%) and one embryo (14.0%). Of the 6,648 TET cycles transferred, 2,356 clinical pregnancies were confirmed by ultrasonography. The most common number of embryos in the TET group was two embryos (43.4%) followed by three embryos (25.4%) and one embryo (18.9%). Conclusion: The clinical pregnancy rate per transfer in the FET cycles was similar in 2009 and 2010. Among the FET cycles where one or two embryos were transferred, the clinical pregnancy rate per transfer slightly increased from 2009 (28.7%) to 2010 (32.9%).

Piezoelectric and ferroelectric properties of (bi,na)tio3–(bi,li)tio3–(bi,k)tio3 ceramics for accelerometer application

Lee, Gyoung‐,Ja,Kim, Byung‐,Hoon,Yang, Sun‐,A,Park, Jin‐,Ju,Bu, Sang‐,Don,Lee, Min‐,Ku American Ceramic Society 2017 Journal of the American Ceramic Society Vol. No.

Simultaneous Voltammetric Determination of Zn, Cd and Pb at Bismuth Nanopowder Electrodes with Various Particle Size Distributions

Lee, Gyoung-Ja,Kim, Chang Kyu,Lee, Min Ku,Rhee, Chang Kyu WILEY-VCH Verlag 2010 Electroanalysis Vol.22 No.5

<P>Effect of particle size distribution on sensor characteristics of nano-Bi fixed electrode has been investigated using square wave anodic stripping voltammetry. Bi nanopowders with various particle size distributions were synthesized by gas condensation (GC) method with the change of chamber pressure. As the chamber pressure decreased, the size of Bi nanopowder became smaller with narrower distribution due to a shorter residence time of Bi vapor. The square wave anodic stripping voltammograms (SWASV) showed well-defined and highly reproducible peaks at −1.2 V, −0.8 V and −0.6 V (vs. SCE), which are closely related to the oxidation of Zn, Cd and Pb, respectively. The sensitivity and detection limit of the nano-Bi fixed electrode were quantitatively estimated from the analyses of SWASV. From the results, it is concluded that as the size of Bi nanopowder becomes smaller with narrower particle size distribution, the sensitivity and detection limit of sensor electrode for Zn, Cd and Pb are improved, which is ascribed to the increase in electrochemical-active surface area.</P>

[P5-24] Characterization of Bacillus amyloliquefancies CH51 with Fibrinolytic Activity

Gyoung Min Kim,Kang Wook Lee,Gun-Hee Kwon,Ae Ran Lee,Woo Ju Jeong,Ji-yeon Chun,Jeong Hwan Kim 한국식품영양과학회 2007 한국식품영양과학회 학술대회발표집 Vol.2007 No.10

Aging-resistant nanofluids containing covalent functionalized boron nitride nanosheets

Lee, Dongju,Park, Jin-Ju,Lee, Min-Ku,Lee, Gyoung-Ja IOP Pub 2017 Nanotechnology Vol.28 No.40

<P>Developing a thermally stable nanofluid that can maintain good thermo-conductive and flow performance at moderate or elevated temperatures for prolonged periods of time is a great challenge in heat transfer applications. Here, the thermal conductivity and rheological properties as well as their thermal stability characteristics of a nanofluid containing two-dimensional (2D) hexagonal boron nitride nanosheets (h-BNNSs) in ethylene glycol (EG) are presented, in comparison with those for a graphene oxide (GO) nanofluid as a counterpart. In place of a surfactant, hydroxyl functional groups covalently bound to the BNNS surface provided excellent compatibility and stable dispersion of the particles within EG at temperatures up to 90 °C. Owing to the percolation effect of the 2D sheets, the thermal conductivity of the EG base fluid was significantly enhanced by 80% at 5 vol% of BNNS, superior to that of the GO fluid. Moreover, the BNNS fluids exhibited excellent long-term stability at 90 °C for 5 d without loss of their high thermal conductivity, low viscosity and electrical insulating property, whereas the GO fluids underwent thermal degradation with irreversible particle aggregation and increasing viscosity due to the selective chemical reduction of the surface functional groups (i.e., C–O groups) of the GO.</P>

Piezoelectric Energy Harvesting from Two-Dimensional Boron Nitride Nanoflakes

Lee, Gyoung-Ja,Lee, Min-Ku,Park, Jin-Ju,Hyeon, Dong Yeol,Jeong, Chang Kyu,Park, Kwi-Il American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.41

<P>Two-dimensional (2D) piezoelectric hexagonal boron nitride nanoflakes (h-BN NFs) were synthesized by a mechanochemical exfoliation process and transferred onto an electrode line-patterned plastic substrate to characterize the energy harvesting ability of individual NFs by external stress. A single BN NF produced alternate piezoelectric output sources of ∼50 mV and ∼30 pA when deformed by mechanical bendings. The piezoelectric voltage coefficient (<I>g</I><SUB>11</SUB>) of a single BN NF was experimentally determined to be 2.35 × 10<SUP>-3</SUP> V·m·N<SUP>-1</SUP>. The piezoelectric composite composed of BN NFs and an elastomer was spin-coated onto a bulk Si substrate and then transferred onto the electrode-coated plastic substrates to fabricate a BN NFs-based flexible piezoelectric energy harvester (f-PEH) which converted a piezoelectric voltage of ∼9 V, a current of ∼200 nA, and an effective output power of ∼0.3 μW. This result provides a new strategy for precisely characterizing the energy generation ability of piezoelectric nanostructures and for demonstrating f-PEH based on 2D piezomaterials.</P> [FIG OMISSION]</BR>

<i>In-situ</i> temperature stability of a piezoelectric accelerometer based on (Bi, Na, K, Li)TiO₃ ceramics

Lee, Gyoung-Ja,Kim, Byung-Hoon,Yang, Sun-A,Park, Jin-Ju,Bu, Sang-Don,Lee, Min-Ku American Institute of Physics 2017 APPLIED PHYSICS LETTERS Vol.111 No.6