급성 심근허혈에 따른 심실활성시간(Ventricular Activation Time)의 변화

한성욱,김윤년,김기영,남창욱,김기식,김권배 대한순환기학회 2001 Korean Circulation Journal Vol.31 No.3

Correlating Structural Changes and Gas Evolution during the Thermal Decomposition of Charged Li_<i>x</i>Ni_0.8Co_0.15Al_0.05O₂ Cathode Materials

Bak, Seong-Min,Nam, Kyung-Wan,Chang, Wonyoung,Yu, Xiqian,Hu, Enyuan,Hwang, Sooyeon,Stach, Eric A.,Kim, Kwang-Bum,Chung, Kyung Yoon,Yang, Xiao-Qing American Chemical Society 2013 Chemistry of materials Vol.25 No.3

<P>In this work, we present results from the application of a new in situ technique that combines time-resolved synchrotron X-ray diffraction and mass spectroscopy. We exploit this approach to provide direct correlation between structural changes and the evolution of gas that occurs during the thermal decomposition of (over)charged cathode materials used in lithium-ion batteries. Results from charged Li<SUB><I>x</I></SUB>Ni<SUB>0.8</SUB>Co<SUB>0.15</SUB>Al<SUB>0.05</SUB>O<SUB>2</SUB> cathode materials indicate that the evolution of both O<SUB>2</SUB> and CO<SUB>2</SUB> gases are strongly related to phase transitions that occur during thermal decomposition, specifically from the layered structure (space group <I>R</I>3̅<I>m</I>) to the disordered spinel structure (<I>Fd</I>3̅<I>m</I>), and finally to the rock-salt structure (<I>Fm</I>3̅<I>m</I>). The state of charge also significantly affects both the structural changes and the evolution of oxygen as the temperature increases: the more extensive the charge, the lower the temperature of the phase transitions and the larger the oxygen release. Ex situ X-ray absorption spectroscopy (XAS) and in situ transmission electron microscopy (TEM) are also utilized to investigate the local structural and valence state changes in Ni and Co ions, and to characterize microscopic morphology changes. The combination of these advanced tools provides a unique approach to study fundamental aspects of the dynamic physical and chemical changes that occur during thermal decomposition of charged cathode materials in a systematic way.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2013/cmatex.2013.25.issue-3/cm303096e/production/images/medium/cm-2012-03096e_0014.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm303096e'>ACS Electronic Supporting Info</A></P>

國內飼育 犬에 있어서 心臟絲狀蟲의 感染率에 관한 調査 硏究

Ji Hee Seong(成知禧),Hwa Joong Yoon(尹和重),Won Chang Lee(李元暢),Kwang Ho Kim(金光浩),Seung Won Kang(姜承遠) 한국예방수의학회 1996 예방수의학회지 Vol.20 No.2

The purpose of this study was carried out an epidemiological survey on the prevalence rate of the canine heartworms in Seoul City and the districts of Pa-Ju, Seong-Nam and Po-Chon in Kyonggi province of Korea from September 1994 to the end of September 1995. The blood samples from 292 male and 193 female dogs (pet, 363 ; fighting dogs, 60 ; working dogs, 62) were examined for the adult heartworms cuticle antibodies using the enzyme-linked immunosorbent assay (ELSA) kits. The test was designed to detect the antibodies of the host against the specific cuticle antigens produced with the adult heartworms.

Analysis of Airtightness and Air Leakage of Wooden Houses in Korea

Sejong Kim,Yoon-seong Chang,Joo-saeng Park,Kug-bo Shim 한국목재공학회 2017 목재공학 Vol.45 No.6

Airtightness of buildings is one of critical aspects of its energy performance. To build up references of air-tightness of wooden houses built in Korea, blower door tests have been carried out in 42 houses since 2006. Causes of air leakage were investigated recently. The average value of air change rate was 3.7 h^-1 for light frame house and 5.5 h^-1 for post-beam construction at ACH50 (air change per hour at 50 Pa air pressure differ-ence). Foam type insulation was more advantageous in ensuring building airtightness than glass fiber batt. Airtightness of wooden houses which were constructed after 2010 was improved to have less than 1.5 h^-1 of ACH50, threshold for application of artificial air change. The average air change rate of CLT (cross laminated timber) houses showed the lowest value, 1.1 h^-1, among the tested structures.

흰쥐 수정란 착상시기에 있어서의 호르몬 농도의 변화와 자궁내막의 구조에 관한 연구

윤미정,손성향,김창미,최임순,Yoon, Mi-Chung,Sohn, Seong-Hyang,Kim, Chang-Mee,Choe, Rim-Soon 한국현미경학회 1993 Applied microscopy Vol.23 No.1

The mechanism by which blastocysts implant to uterine endometrium has not been clearly understood. In the present study, the following question was investigated: how are hormonal levels changed and how is uterine endometrium morphologically changed? Results obtained are as follows: Concentrations of serum estradiol and progesterone were significantly increased on day 4 and 5 of pregnancy. Uterine concentrations of PGE and $PGE_{2a}$ were sharply increased on day 1 and maintained similar concentrations thereafter, reaching the maximum on day 5. Both prostaglandins (PGs) concentrations were gradually decreased thereafter. Furthermore, concentrations of PGs in implant sites were greater than those in non-implant sites. PBR (pontamine blue reaction) in uterine endometrium was positive on day 6 of pregnancy, indicating that vascular permeability was increased. Edema and changes in structure of cell components were pronounced in stroma where PBR was developed. Moreover, these were more prominent in implant sites than non-implant sites. These results suggest that uterine PGs as well as steroid hormones increase during implantation in rats and these hormones might be involved in the process of implantation by modulating vascular permeability and the fine structures of uterine endometrial cells.

Effect of epidural corticosteroid injection on magnetic resonance imaging findings

( Min Soo Kim ),( Tae Yoon Jeong ),( Yu Seon Cheong ),( Young Wook Jeon ),( So Young Lim ),( Seong Sik Kang ),( In Nam Kim ),( Tsong Bin Chang ),( Hyun Ho Seong ),( Byeong Mun Hwang ) 대한통증학회 2017 The Korean Journal of Pain Vol.30 No.4

Background: Magnetic resonance imaging (MRI) of the spine is the preferred diagnostic tool for pathologic conditions affecting the spine. However, in patients receiving epidural corticosteroid injection (ESI) for treatment of spinal diseases, there is a possibility of misreading of MR images because of air or fluid in the epidural space after the injection. Therefore, we defined the characteristics of abnormal changes in MRI findings following an ESI in patients with low back pain. Methods: We reviewed the medical records of 133 patients who underwent MRI of the lumbar spine within 7 days after ESI between 2006 and 2015.All patients were administered an ESI using a 22-gauge Tuohy needle at the lumbar spine through the interlaminar approach. The epidural space was identified by the loss of resistance technique with air. Results: The incidences of abnormal changes in MRI findings because of ESI were 54%, 31%, and 25% in patients who underwent MRI at approximately 24 h, and 2 and 3 days after ESI, respectively. Abnormal MRI findings included epidural air or fluid, needle tracks, and soft tissue changes. Epidural air, the most frequent abnormal finding (82%), was observed in 41% of patients who underwent MRI within 3 days after injection. Abnormal findings due to an ESI were not observed in MR images acquired 4 days after ESI or later. Conclusions: Pain physicians should consider the possibility of abnormal findings in MR images acquired after epidural injection using the interlaminar approach and the loss of resistance technique with air at the lumbar spine. (Korean J Pain 2017; 30: 281-6)

풍동실험을 통한 수평축 풍력터빈 모델의 공력성능 연구

유기완(Ki-Wahn Ryu),윤성준(Seong-Jun Yoon),이창수(Chang-Su Lee),최성옥(Seong-Ok Choy) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.11

공기역학적으로 최대동력계수를 얻을 수 있도록 최적화된 블레이드를 장착한 수평축 풍력터빈 모델을 아음속 풍동에 장착하여 공력특성을 실험하였다. Upwind 방식과 downwind 방식의 풍력 터빈 로터의 공력 특성을 비교하였을 때, 후자가 전자에 비해 측정토크의 교란이 더 크게 나타났으며, 이는 지지대에서 발생된 후류와 블레이드의 상호간섭이 원인으로 작용한다고 여겨진다. 블레이드 설치각이 0°인 경우에 설계 속도비 6에 해당하는 위치에서 최대 동력계수를 보여주고 있어 설계 조건을 잘 만족함을 알 수 있었다. 또한 음의 피치각 변화가 같은 값의 양의 피치각 변화에 비해 더 커다란 동력 감소가 발생되는 결과를 보여주었다. Wind turbine experiment was carried out for the horizontal axis wind turbine with the aerodynamically optimized blade. From the comparison of aerodynamic performance between upwind and downwind type wind turbine rotor, the measured torque fluctuation of the latter is larger than that of the former. This phenomenon is owing to the interaction of wake generated from support column and blades. The wind turbine model satisfies the design condition in that the measured result of the power coefficient at zero pitch angle shows maximum peak at the designed tip speed ratio, λ= 6. It also shows that the decrease in aerodynamic power due to negative pitch change is more sensitive than that of the same positive pitch change.

Using Real-Time Electron Microscopy To Explore the Effects of Transition-Metal Composition on the Local Thermal Stability in Charged Li_<i>x</i>Ni_<i>y</i>Mn_<i>z</i>Co_{1–<i>y</i>–<i>z</i>}O<sub>2</sub

Hwang, Sooyeon,Kim, Seung Min,Bak, Seong-Min,Kim, Se Young,Cho, Byung-Won,Chung, Kyung Yoon,Lee, Jeong Yong,Stach, Eric A.,Chang, Wonyoung American Chemical Society 2015 Chemistry of materials Vol.27 No.11

<P>In this work, we use in situ transmission electron microscopy (TEM) to investigate the thermal decomposition that occurs at the surface of charged LixNiyMnzCo1-y-zO2 (NMC) cathode materials of different composition (with y, z = 0.8, 0.1, and 0.6, 0.2, and 0.4,and 0.3), after they have been charged to their practical upper limit voltage (4.3 V). By heating these materials inside the TEM, we are able to directly characterize near surface changes in both their electronic structure (using electron energy loss spectroscopy) and crystal structure and morphology (using electron diffraction and bright-field imaging). The most Ni-rich material (y, z = 0.8, 0.1) is found to be thermally unstable at significantly lower temperatures than the other compositionsthis is manifested by changes in both the electronic structure and the onset of phase transitions at temperatures as low as 100 degrees C. Electron energy loss spectroscopy indicates that (i) the thermally induced reduction of Ni ions drives these changes, and (ii) this is exacerbated by the presence of an additional redox reaction that occurs at 4.2 V in the y, z = 0.8, 0.1 material. Exploration of individual particles shows that there are substantial variations in the onset temperatures and overall extent of these changes. Of the compositions studied, the composition of y, z = 0.6, 0.2 has the optimal combination of high energy density and reasonable thermal stability. The observations herein demonstrate that real-time electron microscopy provide direct insight into the changes that occur in cathode materials with temperature, allowing optimization of different alloy concentrations to maximize overall performance.</P>

Wechsler 記憶檢査(改訂版)의 妥當度 硏究

韓五洙,柳希姃,金晟倫,金昌潤,李楨敎,李哲,朴仁鎬 서울醫大 1997 精神醫學 Vol.22 No.1

5, 7-DHT가 흰쥐 등쪽솔기핵내 신경아교세포에 미치는 영향

채제명(Je Myung Chae),조승묵(Seung Mook Jo),남성안(Seong Ahn Nam),윤상선(Sang Seon Yoon),고병문(Byung Moon Ko),최창도(Chang Do Choi),최월봉(Wol Bong Choi) 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.1

신경독성물질인 5, 7-dihydroxytryptamine (5, 7-DHT)이 중추신경계통내 serotonin 신경세포에 미치는 영향과 이에 따른 신경아교세포들의 반응을 형태학적으로 규명하고자 본 연구를 시행하였다. 흰쥐의 가쪽뇌실에 5, 7-DHT(200μg)를 투여한 후면역세포화학적 염색을 시행한 후 광학 및 전자현미경하에서 등쪽솔기핵내 serotonin 신경세포에 초래되는 퇴행성변화와 주위 신경아교세포들의 반응양상 등을 경시적으로 (1, 3, 5, 10 및 20일) 관찰하였던 바 아래와 같은 결과를 얻었다. 흰쥐 등쪽솔기핵내 5, 7-DHT의 세포독성에 반응을 보인 신경아교세포로는 미세아교세포와 별아교세포였으며, 이들 세포 들의 반응양상은 매우 특징적이었으며, 상당한 차이를 보였으며, 전반적으로 미세아교세포가 별아교세포에 비해 빠른 변화소견을 보였다. 즉, 미세아교세포의 경우 실험 3일군 및 5일군에서 이미 그 수의 증가와 함께 활발한 포식작용을 보였던 반면, 별아교세포는 후기 실험군인 10일군 및 20일군에 이르러서야 세포질의 비대 및 수적 증식을 통하여 손상된 신경조직을 보상할 뿐 아니라 밀집된 미세아교세포들을 분산시키는 소견이 관찰되었다. 그러나 희소돌기아교세포는 본 연구의 전 실험군을 통하여 특별한 변화소견이 관찰되지 않았다. 이상의 결과로 부터 5, 7-DHT가 흰쥐 등쪽솔기핵내 신경세포에 강한 세포독성을 유발하며, 이에 따른 주위 신경아교세 포들 특히 미세아교세포와 별아교세포는 시간경과에 따라 매우 다양한 반응양상을 보인다는 사실을 알게 되었다 This study was designed to clarify the cytotoxic effects of 5, 7-dihydroxytryptamine (5, 7-DHT) on the serotonergic neurons in the dorsal raphe nucleus, and to investigate the glial reaction during the neurodegenerative changes by light and electron microscopy. Adult male rats (Sprague-Dawley strain) weighing from 250 g to 350 g each were used as experimental animal. 5, 7-DHT(200 μg dissolved in 0.9% NaCl) was injected into the lateral ventricle of the rat brain with the Hamiton syringe fixed on stereotaxic apparatus. The control rats were given with the similar volume of 0.9% NaCl. The rats were sacrified on the 1st, 3rd, 5th, 10th and 20th day after the injection of 5, 7-DHT. The results were as follows : Glial reactions induced by 5, 7-DHT were also observed in DRN. In early experimental stage, microglial reactions prevailed, whereas astroglial reactions were prevailing in later stage. In addition, microglial cells phagocytosed and removed the degenerated cells. However, astrocytes in DRN did not show phagocytotic activities such as microglial cells. Based on the results, author thought that 5, 7-DHT act as a specific neurotoxin to serotonergic neurons in DRN, and induces severe neurodegenerative changes. The glial reactions in DRN are activated during the neurodegerative changes, and show characteristic patterns of glial reactions.