감초 추출물이 면역응답에 미치는 영향

심호기,백반석,황성원,배만종 경산대학교 생명자원개발연구소 1996 생명자원과 산업 Vol.1 No.-

감초에서 분리한 각각의 추출물(HWE, ME, AE)을 BALB/c mouse에 투여하여 탐식작용, 용혈반형성, 용혈소 역가특정 및 Rosette형성 실험을 통해 감초가 면역응답에 미치는 영향을 조사하였다. 1. 탐식능 측정에서 복강침출세포(PEC)와 비장세포(spleen cell)는 CON군에 비하여 가각의 약물투여군이 Candida parapsilosis에 대한 효과가 약간 높은 경향을 나타냈지만 유의성은 없었다. 2. 용혈반 형성 및 용혈소 역가측정에서는 CON군에 비하여 HWE, ME, AE투여 군이 유의성을 나타냈다. 3. Rosette형성에 대한 측정에서는 CON군에 비하여 ME, AE투여 군이 높은 유의성을 나타냈다. 본 실험 결과에서 감초 추출물들은 Candida paraprapsilosis에 대하여 약간의 탐식증진효과를 나타냈으며, 항체생성세포의 용혈반 시험 및 용혈소 역가측정과 Rosette형성측정에서의 유의성을 나타낸 것은 감초가 세포성 면역을 주도하는 T세포를 활성화시킬 뿐만 아니라, 체액성 면역을 주도하는 B세포를 활성화시킨다는 것을 확인 할 수 있다. The inverstigation of effecting immune response on BALB/c mouse was experimented with hot water extract(HWE), 50% methanol extract(ME) and aaceton extract(AE) 〔which was extracted from Glycyrrhiza glabra〕. The experiment was carried out by phagocytosis, hemolytic plaque assay, hemolysin titration and rosette assay. Peritoneal exudative cells and spleen cells in phagocytosis ability; the experimental group has shown a slight increase in Candida parapsilosis(HWE, ME & AE). The experiment shows no relevant correlation. The experiment of hemolytic plaque assay and hemolysin titration was treated by HWE, ME and AE. The experimental group was treated by ME and AE through the measurement of rosette assay. The experimental group has given significant increase compared with the control. As the result, the extracts of Glycyrrhiza glabra (HWE, ME and AE) has effedted slightly to Cnadida parapsilosis in phagocytosis. The reason of effecting the immunocyte in hemolysin titration, rosette assay and hemolytic plaque assay ; Glycyrrhiza glabra has activated the T-cell which controlled cell mediated immunity. Same with B-cell which could also control humoral immunity.

고효율 DC/DC컨버터 제작을 위한 동기정류기 도전 손실 해석

윤석호,김용,백수현,김필수 동국대학교 산업기술연구원 1999 산업기술논문집 Vol.14 No.-

최근 반도체 소자의 제조기술 발달로 정보통신기기 등에 사용되는 온보드(on-board) 컨버터의 전원전압은 3.3V 또는 1.5V의 저전압 전원이 사용된다. 이러한 저전압 전원방식은 온보드(on-board) 컨버터의 정류기단 전력손실이 증가하게 되어 시스템의 높은 효율을 얻기가 어렵게 된다. 낮은 전원전압 방식일수록 정류기단에서 전력손실은 더욱 증가하여 컨버터의 효율은 낮아진다. 고전력밀도의 정류기단 구성을 위하여 출력단에 다이오드 대신 MOSFET 자기구동 정류기를 사용한다. 그러나 MOSFET 자기구동 정류기의 전력손실은 2차측 구동전압의 형태나 기생인덕턴스의 영향을 받게 된다. 따라서 불연속에서는 기생인덕턴스에 의한 MOSFET와 쇼트키 다이오드의 도통주기의 변화가 MOSFET 자기구동 정류기의 전력손실에 미치는 영향을 분석하였으며, 그 결과 기생인덕턴스의 크기를 감소시켜 MOSFET의 도통주기를 증가시킴으로써 MOSFET 자기구동 정류기의 전력손실을 최소화하였다. Recently, new trend in telecommunication device is to apply low voltage, about 3.3V-1.5V. However, it is undesirable in view of high efficiency and power desity which is the most important requirement in the distributed power system. Rectification loss in the output stage in on-board converter for distributed power system are constrained to obtain high efficience at low output voltage power supplies. This paper is investigated conduction power loss in synchronous rectifier with a parallel connected Schottky Barrier Diode(SBD). Conduction losses are calculated for both MOSFET and SBD respectively. The SBD conduction power loss dissipates more than the MOSFET rectifier conduction power loss.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

태극권 수련이 중년여성의 심리적 행복감에 미치는 영향

강현숙,김백윤,박미진,신영호 한국스포츠리서치 2005 한국 스포츠 리서치 Vol.16 No.2

The purpose of this study was to explore the effects of Taichichuan training on the variables of cognitive-affective states. The subjects of the study consisted of 22G middle aged women in Jeonju areas. The survey methods of this research are the 5 Likert Scale modified the Cognitive Affective States Scale by Yang. Myung-Hwan(1998). The used statistical methods for the data analysis were M. SD. Paired sample T-Test. The results obtained by the appropriate analytic processes were followed. 1. In hedonic enjoyment, Taichichuan training women were lower than non-activity women. 2. In feeling of flow, Taichichuan training women were higher than non-activity women. 3. In self-realization, Taichichuan training women were higher than non-activity women. 4. In self-confidence, Taichichuan training women were higher than non-activity women.

모듈러 파워 프로세서를 위한 DC/DC컨버터의 효율 및 특성 비교

김용,백수현,윤석호,김필수 東國大學校 1998 東國論叢 Vol.37 No.-

본 논문에서는 분산전원시스템의 모듈러 파워 프로세서(Modular Power Processor : MPP)를 위한 중첩형 액티브클램프 ZVS 포워드 컨버터와 ZVS 하프 브리지(Half bridge) 컨버터의 동작특성과 효율을 비교하였다. 또한 중첩형 액티브클램프 ZVS 포워드컨버터의 전류모드 제어회로 설계바업을 제시하였고 게이트 구동회로를 간단히 하기 위해 N-P MOSFETs로 조합된 액트클랩프 기법을 제한하여 50∼100% 부하 범위에서 약 90%의 효율을 얻을 수 있었다, This paper compared to the characteristic and efficiency of an interleaved active clamp ZVS forward converter and an interleaved ZVS half-bridge converter for a modular power processor in distributed power system. the design for the current-mode control circuit of an interleaved active clamp ZVS forward converter is presented. To simplify the gate drive circuits. N-P MOSFETs coupled active clamp method is proposed. an efficiency about 90% for the 50-100% load range is achieved.

동기정류방식에 의한 하프브리지 컨버터의 효율개선에 관한 연구

김용,고승모,백락준,김필수,윤석호 東國大學校 1999 東國論叢 Vol.38 No.-

The effort to increase operating frequency in order to reduce weight, size and coast of magnetic and filter elements is constantly hampered by higher switching stresses and switching losses. And the evolution in the digital integrated circuits in demanding lower power supply voltage. In a few years, 3.3V may be standard. In converters with such a low output voltage, it is quite difficult to achieve high efficiency due to the rectifier diodes of the output stage what limits the reduction converter size. To over come theses obstacles, this paper proposes the ZVS Half-Bridge converter using Self-driven Synchronous Rectifier. Using resonant condition of the transformer primary side series equivalent inductance and parasitic capactiance of the switching device, the circuit operates in zero-voltage switching. The steady state equation and ZVS condition are derived. The Zero Voltage Switching is analyzed taking into account the effect of the parasitic capacitance of the MOSFET rectifiers on the transformer secondary side. The Zero voltage Switching condition is established. Simulation and experimental result are compared.

2-D 모델을 이용한 軸磁界形 브러시레스 直流 電動機의 磁界解析

김필수,김용,백수현,윤석호 동국대학교 산업기술연구원 1997 산업기술논문집 Vol.9 No.-

본 연구에서는 2-D 자계 시뮬레이터를 이용하여 축 자계형 브러시레스 직류 전동기의 자계해석을 위한 방법을 제시하였다. 브러시레스 직류 전동기의 정확한 자계해석을 위해서는 3-D 해석이 필요로 된다. 그러나 이러한 해석은 시간과 비용이 크게 소요되므로 모터 설계를 위해서는 적당하지 못하다. 따라서 본 연구에서는 이러한 자계 해석을 위해서 전동기 영구자석의 평균 반지름에 대하여 원통 모양의 절단면을 이용하여 3-D 문제를 2-D 경계치 문제로 감소시켰다. 따라서 본 방법은 축 자계형 전동기의 크기 및 형태에 관계없이 합리적인 2-D 자계 결과를 얻을 수가 있다. This paper describes a method for field analysis inside the axial-field brushless DC motors using 2-D field simulator. Rigorous field analysis for brushless DC motors entail 3-D analysis. However, this analysis are not often appropriate for motor designs because of the time and cost involved. For field analysis in this study, the 3-D problem is reduced to a 2-D boundary value problem by introducing a cylindrical cutting plane at the mean radius of the magnets. Independent of sizes and shapes of axial-field motors, the exact 2-D field results can be obtained with reasonable predictability.

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

Optical Properties of Ge-Doped ZnO Thin Films Studied with Spectroscopic Elipsometry

Seoung Ho Baek,Do Kyu Lee,강태동,Suk-Ho Choi,이호선,Seung Hwan Eom 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.1

We prepared Ge-doped ZnO (ZnO : Ge) thin films on silicon substrates by using RF magnetron sputtering. We used as targets mixtures of ZnO and Ge, the RF power was 70 and 150 W and the Ge mole ratio was varied between 0 mol% and 3 mol% with respect to the ZnO content. During growth, we used two kinds of gas ows: Ar : O₂ = 40 : 5 and Ar : N2 = 40 : 5. The substrate temperatures were kept at room temperature (RT) and 400 ℃. We measured the pseudo-dielectric functions by using spectroscopic ellipsometry at RT. By using the parametric optical constant model and performing alayer model analysis, we obtained the Kramers-Kronig-consistentdielectric functions of the ZnO : Ge films. To find the band gap energies of the ZnO : Ge films, we applied the standard critical point model to the 2nd derivatives of the dielectric functions (ε = ε₁ +ⅰε₂) of the ZnO : Ge films. Among the ZnO : Ge films grown on Si substrates, the thin films grown in the Ar and O₂ mixture showed dielectric functions closer to that of a purely crystalline ZnO film,which indicate shigh crystallinity. Theband-gapenergies of the ZnO:Ge film sincreased with increasing Ge content. We attribute the blue shift of the band-gap energy to the Burstein-Moss shift (band-filling effect) and/or to the alloying effect of ZnO : Ge. The larger blue shift of the ZnO : Ge films grown in the Ar and N₂ mixture suggests that more carriers were activated in that mixture than in the Ar and O₂ mixture. With increasing Ge content, the linewidth broadened due to an increase in alloy disorder. In the case of ZnO : Ge grown under a gas flow ratio of Ar : N₂ = 40 : 5, a deep-level transition was observed near 2.5 eV in the dielectric function spectra and is attributed to atransition related to oxygen vacancies. In order to investigate the effect of annealing on the ZnO : Ge films, we annealed the ZnO : Ge films grown on silicon substrates at RT with a gas how ratio of Ar : O₂ = 40 : 5 in oxygen (O2) ambient. When the annealing temperature was increased, both the band gap energy and broadening parameter of the ZnO : Ge film decreased.

The Basic Study on the Registration of Korean On dol Technology to the UNESCO World Heritage

Kim June Bong,Rhee GuangHoon,Ok Jong Ho,Baek Suk Jong 국제온돌학회 2014 International Journal of Ondol Vol.7 No.1