高血壓 白鼠의 腦神經細胞膜 Na-K-ATPase에 關한 硏究

金永煥,薛鍾求,李俊揆 충남대학교 의과대학 지역사회의학연구소 1989 충남의대잡지 Vol.16 No.1

To study synaptosomal Na-K-ATPase in the renal hypertensive rats, right kidney was removed and left renal artery was partially ligated 9external diameter=0.38mm) for pyertensive group. For control, right kidney was removed. At four weeks after operation, blood pressure ws monitored with physiography from carotid artery. Synaptosome was prepared from cerebrum to investigate the activity of Na-K-AFTase in the absence of the presence of saponin, Rb-uptaek and ouabain binding experiment. Results are as follows; 1. Blood pressure was significantly increased to 177.4/121.6mmHg in 1-kidney hypertensive rat. 2. In the presence of saponin, total, EGTA-sensitive, azide-sensitive and Na-K-ATPase activity were increased about two folds compared to those in the absence of saponin. 3. In the absence of saponin, Na-K-ATPase activity was significantly decreased compared to control group. These results were the same as in the presence of saponin. 4. ^86Rb-uptake inhibited by ouabain was significantly decreased (about 37%) in the hypertensive group compared to control group. 5. In the ouabain binding experiment, vlaue of Bmax in hypertensive group was decreased signficantly(about 32%), but there was no differnece in the value of Kd between both groups. From these results, it is suggested that the function of central nervous system may be altered due to decreased number of pump or activity of Na-K-ATPase in the 1-kidney, 1-clip hypertensive rats.

인버터 구동시의 유도전동기의 정상상태특성

정영준,좌종근 濟州大學校 情報通信硏究所 2000 情報通信硏究所論文集 Vol.3 No.-

In this paper. the Γ type eqivalent circuit is used to analyze the steady state characteristics of induction motor driven by inverter source. The base tests for equivalent circuit parameters of induction motor are a no-load test by rated frequency (60Hz) and a blocked rotor test by 25% of rated frequency (15Hz) which are perfomed with inverter source. and measurement of the de resistance of the stator winding. To determine more accurate parameters, four simultaneous equations obtained from equivalent circuit of the no-load test and blocked rotor test are solved by using initial values which are evaluated from simplifed equivalent circuits. The induction motor performances are computed by using these parameters and compared with measured values of the tested motor. Then it is found that the compared results show good agreement between them.

관동맥 스텐트 삽입후 발생한 스텐트 변연부 박리의 예측인자 및 추가적 치료후 임상적 의의에 관한 연구 : Predictor, Angiographic and Clinical Follow-up after Additional Procedures

두영철,박수종,김재삼,이준호,홍경순,박대균,한규록,오동진,유규형,임종윤,고영박,이광학,이영 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.11

Crucial Role of Oxidation Debris of Carbon Nanotubes in Subsequent End-Use Applications of Carbon Nanotubes

Kim, Yern Seung,Oh, Jun Young,Kim, Jae Ho,Shin, Min Ho,Jeong, Yo Chan,Sung, Sae Jin,Park, Jisoo,Yang, Seung Jae,Park, Chong Rae American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.20

<P>A facile purification method for oxidized carbon nanotubes (CNTs) is developed to preserve acidic carbon compounds (ACCs) for achieving high-quality dispersion of CNTs. The remaining ACCs, which originated from the surface destruction of CNTs during the oxidation process, are considered to play a crucial role in the dispersion of CNTs in water and various polar protic solvents. To elucidate the concrete role of ACCs, a direct titration method is applied to quantitatively investigate the degree of ionization of both CNTs and ACCs in their aqueous dispersion. While ACCs with strong carboxylic groups (pK(a) of around 2.9) are easily removed by the neutral or base washing of oxidized CNTs, which is common in the purification process, ACC-selective purification using acid washing preserves the ACCs attached to CNTs, thereby effectively stabilizing CNT dispersions in aqueous solutions. Additionally, the Hansen solubility parameters of ACC-preserved and ACC-removed CNTs were determined by the inverse gas chromatography method to estimate their miscibility in various solvents. The preserved ACCs significantly influenced the dispersibility of CNTs in polar protic solvents, which may widen the possible application of CNTs. Specifically, the ACC-preserved high-quality CNT dispersion produces high-performance CNT buckypaper with densely packed nanostructures. The Young's modulus and tensile strength of these buckypapers reach up to 12.0 and 91.0 MPa, respectively, which exceed those of ACC-removed CNTs in previous reports.</P>

하악골 절제술후 재이식된 돌결자가골 재이식 : 치험 3례

김 식,김수관,김운규,김수민,류종희,이준길,조경안,김수흥,정태영,여환호 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.2

We described three cases of immediate reimplantation of a frozen-thawed autogenous mandible composed of a mixture of iliac bone, marrow, and particulate hydroxyapatite in tumors of the mandible. Acceptable outcomes were obtained in three patients who underwent immediate autogenous mandibular graft reconstruction. The conditions leading to successful outcome of the procedure are also discussed. Reimplantation of frozen autogenous lesioned mandible was performed in three patients with mandibular tumors. Two reimplanted grafts survived without complications following surgery. One case had postoperative infection that resolved with appropriate antibiotic treatment. There were no recurrences of the primary lesions. Satisfactory facial contour after surgery was achieved. These results are most promising, and we believe that, with further refinement, this technique will offer a new and acceptable modality for facial reconstruction in patients with cancer.

장티푸스 진단에 있어서 Vi-Indirect Fluorescent Antibody Test의 민감도 및 특이도

장경희,류동렬,박성하,박병규,이준구,염준섭,최영화,송영구,김현숙,정윤섭,김준명 대한감염학회 1998 감염 Vol.30 No.4

목 적 : 장티푸스는 체액의 세균배양검사에서 Salmonella typhi의 분리로 확진하지만 조기진단을 위해서는 혈청학적인 검사가 도움이 된다. 저자 등은 1989년 이후 장티푸스진단에 S. typhi의 Vi항원을 이용한 간접형광항체법 (Vi-indirect fluorescent antibody test : Vi-IFAT)을 도입하였다. 이에 지난 7년간의 검사결과를 토대로 Vi-IFAT의 민감도 및 특이도를 규명하고자 하였다. 방 법 : 1989년부터 1996년까지 연세대학교 의과대학 세브란스 병원에 발열을 주소로 내원하여 Vi-IFAT가 의뢰된 환자 중 발열의 원인이 확진된 744명의 환자를 대상으로 하였으며, Vi-IFAT에 있어서 양성반응은 1:64이상으로 하였다. 결 과 : 1) 세균배양검사에서 확진된 장티푸스 환자 178예 중 168예에서 양성반응을 보여 민감도는 94.4%이었다. 항체가는 1:64가 89예, 1:128이 36예, 1:256이 27예, 그리고 1:512가 16예이었다. 위음성이었던 10예의 항체가는 1:32가 7예, 1:16이하가 3예이었다. 2) 발열을 주소로 내원한 환자 중 장티푸스 이외의 다른 질환으로 확진된 566예 중 538예에서 음성반응을 보여 특이도는 95.1%이었다. 항체가는 1:32가 117예, 1:16이하가 421예이었다. 위양성이었던 28예의 항체가는 1:64가 23예, 1:128이 5예이었으며, 장티푸스 이외의 살모넬라증이 4예, 요로계감염이 10예, 소화기계감염이 6예, 호흡기 계감염이 5예, 악성 종양이 2예, 그리고 바이러스 감염이 1예이었다. 3) Vi-IFAT 양성인 196예 중에서 장티푸스는 168예로 양성예측율은 85.7%이었으며, Vi-IFAT 음성인 548예 중 장티푸스 이외의 발열질환은 538예로 음성예측율 98.2%이었다. 4) 배양검사와 Widal test 사이의 일치율 (Kappa value)는 0.28로 poor agreement를 보였으며 Vi-IFAT와 Widal test 사이의 Kappa value는 0.74로 good agreement를 보였다. 그러나 배양검사와 Vi-IFAT 사이의 Kappa value는 0.86으로 excellent agreement를 보여 일치율이 가장 높은 검사는 배양검사와 Vi-IFAT라 할 수 있겠다. 5) 장티푸스 환자에 있어서 Vi-IFAT의 양성율은 발열기간이 1중 미만인 환자에서는 68%, 1내지 2주인 환자에서는 89.5%, 2주이상인 환자에서는 100%이었다. 결 론 : Vi 항원을 이용한 간접형광항체법 (Vi-IFAT)은 장티푸스 진단에 높은 민감도 및 특이도를 가지며, 또한 조기진단에 있어서도 임상적으로 유용함을 확인할 수 있었다. Background : Typhoid fever is diagnosed by culture or serological study. The confirmative diagnosis of typhoid fever is made by culture of the causative organism usually from body fluids. Serological test is a supportive diagnositic tool, which is useful for early diagnosis. In Severance Hospital, Vi-indirect foluorescent antibidy test(Vi-IFAT) using the Vi-antigen of Salmonella typhi has been used in the diagnosis of typhoid fever since 1989. We investigated the test results from the past 7 years, in order to clarify the sensitivity and specificity of Vi-IFAT. Methods : A retrospective study was done on patients whose chief complaint was fever and who were tested using Vi-IFAT in the Severance Hospital from 1989 to 1996. The positive value for Vi-IFAT was defined as 1:64 or higher. Results : The sensitivity and specificity of Vi-IFAT for typhoid fever was 94.4% and 95.1%, respectively. The positive and negative predictive values were 85.7% and 98.2% respectively. Positive rates of Vi-IFAT after fever onset increased with time and 68% were positive before the first week. From the first to the second week, 89.5% were positive and after the second week, 100% were positive. Conclusion : Vi-IFAT is not only a valuable serologic test for the diagnosis of typhoid fever, but also useful in the early diagnosis of the disease.

Easy Preparation of Readily Self-Assembled High-Performance Graphene Oxide Fibers

Kim, Yern Seung,Kang, Jong Hun,Kim, Taehoon,Jung, Yeonsu,Lee, Kunsil,Oh, Jun Young,Park, Jisoo,Park, Chong Rae American Chemical Society 2014 Chemistry of materials Vol.26 No.19

<P>Graphene oxide (GO) was recently reported to assemble into one-dimensional fiber precursors that can be used to produce next-generation multifunctional graphene-based materials. This study describes the facile fabrication of GO fibers with excellent mechanical properties, utilizing a diamine cross-linker that forms ion bridges between the GO layers. Organic co-coagulants and postdrawing processes, which are usually employed in typical GO spinning processes, were not used here. The GO layers readily aligned along the spinning axis, and the GO formed closely packed structures in the fibers. The fibers displayed a Young’s modulus of 26.6 GPa and a maximal tensile strength of 384.3 MPa. The interlayer microstructure of the GO sheets could be tuned by modifying the structures of the cross-linking diamine groups, yielding a range of mechanical properties. These observations suggested that our newly developed GO fiber synthesis method could allow applications of graphene-based fibrous materials through GO surface chemistry modification approaches.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2014/cmatex.2014.26.issue-19/cm502614w/production/images/medium/cm-2014-02614w_0008.gif'></P>

A Study on μBGA Solder Joints Reliability Using Lead-free Solder Materials

Young-eui Shin,Jun-Jun-Hwan Lee,Young-Wook Koh,Chong-Won Lee,Jun-Ho Yun,Seung-Boo Jung 대한기계학회 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.7

In this study, the numerical prediction of the thermal fatigue life of a ,μBGA (Micro Ball Grid Array) solder joint was focused. Numerical method was performed using the three-dimensional finite element analysis for various solder alloys such as Sn- 37%Pb, Sn- 3.5%Ag, Sn- 3.5%Ag-0.7%Cu and Sn-3.5%Ag-3%ln-0.5%Bi during a given thermal cycling. Strain values obtained by the result of mechanical fatigue tests for solder alloys, were used to predict the solder joint fatigue life using the Coffin-Manson equation. The numerical results showed that Sn- 3.5%Ag with the 50-degree ball shape geometry had the longest thermal fatigue life in low cycle fatigue. A practical correlation for the prediction of the thermal fatigue life was also suggested by using the dimensionless variable ??. Additionally Sn-3.5Ag-0.75Cu and Sn-2.0Ag-0.5Cu-2.0Bi were applied to 6×8μBGA obtained from the 63Sn-37Pb Solder. This 6×8μBGA were tested at different aging conditions at 130℃,150℃, 170℃ for 300, 600 and 900 hours. Thickness of the intermetallic compound layer was measured for each condition and the activation energy for their growth was computed. The fracture surfaces were analyzed using SEM (Scanning Electron Microscope) with EDS (Energy Dispersive Spectroscopy).<br/>

Improved Transmitter Power Efficiency using Cartesian Feedback Loop Chip

Young-Jun Chong,Il-Kyoo Lee,Seung-Hyeub Oh 한국전자파학회JEES 2002 Journal of Electromagnetic Engineering and Science Vol.2 No.2

The Cartesian loop chip which is one of key devices in narrow-band Walky-Talky transmitter using RZ-SSB modulation method was designed and implemented with 0.35 ㎛ CMOS technology. The reduced size and low cost of transmitter were available by the use of direct-conversion and Cartesian loop chip, which improved the power efficiency and linearity of transmitting path. In addition, low power operation was possible through CMOS technology.<br/> The performance test results of transmitter showed -23 dBc improvement of IMD level and -30 dBc below suppression of SSB characteristic in the operation of Cartesian loop chip (closed-loop). At that time, the transmitting power was about 37 dBm (5 W). The main parameters to improve the transmitting characteristic and to compensate the distortion in feed back loop such as DC-offset, loop gain and phase value are interfaced with notebook PC to be controlled with S/W.<br/>

New Genetic Variants of Anaplasma phagocytophilum, A. bovis and A. centrale in the Korean Water Deer, Haemaphysalis and Ixodes spp. in Korea

Jun gu Kang,Jae young Oh,Sung jin Ko,Young Jun Kim,Hyo Jin Yang,Hang Lee,Nam shik Shin Terry A. Klein,Heung Chul Kim,Sung Tae Chong,Joon seok Chae 대한수의학회 2009 대한수의학회 학술대회발표집 Vol.2009 No.-