Comparison of trophic factors changes in the hippocampal CA1 region between the young and adult gerbil induced by transient cerebral ischemia.

Yan, Bing Chun,Park, Joon Ha,Kim, Sung Koo,Choi, Jung Hoon,Lee, Choong Hyun,Yoo, Ki-Yeon,Kwon, Young-Geun,Kim, Young-Myeong,Kim, Jong-Dai,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2012 Cellular and molecular neurobiology Vol.32 No.8

<P>In the present study, we investigated neuronal death/damage in the gerbil hippocampal CA1 region (CA1) and compared changes in some trophic factors, such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF), in the CA1 between the adult and young gerbils after 5 min of transient cerebral ischemia. Most of pyramidal neurons (89%) were damaged 4 days after ischemia-reperfusion (I-R) in the adult; however, in the young, about 59% of pyramidal neurons were damaged 7 days after I-R. The immunoreactivity and levels of BDNF and VEGF, not GDNF, in the CA1 of the normal young were lower than those in the normal adult. Four days after I-R in the adult group, the immunoreactivity and levels of BDNF and VEGF were distinctively decreased, and the immunoreactivity and level of GDNF were increased. However, in the young group, all of their immunoreactivities and levels were much higher than those in the normal young group. From 7 days after I-R, all the immunoreactivities and levels were apparently decreased compared to those of the normal adult and young. In brief, we confirmed our recent finding: more delayed and less neuronal death occurred in the young following I-R, and we newly found that the immunoreactivities of trophic factors, such as BDNF, GDNF, and VEGF, in the stratum pyramidale of the CA1 in the young gerbil were much higher than those in the adult gerbil 4 days after transient cerebral ischemia.</P>

인체 공중 동작 시뮬레이션 프로그램 개발

성낙준,권영후 한국운동역학회 1994 한국운동역학회지 Vol.4 No.2

A comprehensive simulation software package was developed in C base on the work done by Yeadon et al.(1990) and Kwon (1993a) in the aim of making it easy to apply the experimental simulation technigues to the human airborne movement studies. This package consists of 3 programs: simulation variable computation program (PREP), simulation program (SIM) and the 3-dimensional graphic program (3DMAN). All programs are driven by an easy-to-use menu system and written compatible to KWON3D Motion Analysis Package Version 2.1 (Kwon, 1993b). Program PREP consists of 4 menus: `Edit Data´, `Prepare´ `Angular Momentum´ and `Optimization´. The `Edit Data´ environment is an editor for the lengths of the segments and body lines. The `Prepare´ menu computes the internal orientation angles of the segments while the `Angular Momentum´ menu computes the mean airborne angular momentum of the body and other initial conditions such as the initial position and velocity of the body CM and the initial external orientation of the body. The `Optimization´ menu performs angular momentum optimization proposed by Kwon (1993a). A geometric 15-segment body model - Yeadon-Kwon model (Kwon, 1993b) - with at most 38 degrees of freedom including 3 external orientation angles (somersault, inclination and twist angles) was employed to compute the simulation variables. SIM consists of 2 menus: `Edit Angles´ and `Simulate´. The `Edit Angles´ environment is an editor for the internal orientation angles of the segments. Users can intentionally manipulate the internal orientation angles for the simulation of modified trials. The program displays time-angle curves segment by segment. The `Simulate´ menu actually performs simulation. The initial conditions can be directly manipulated in the program menu environment. The simulation program was tested by several theoretical configurations to screen out the flaws in the theory and to isolate coding mistakes. The simulated results were compared with the predicted results and the program showed good agreements between the simulated results and the theoretical predictions. The simulation program was then applied to several gymnastic maneuvers and springboard dives for testing. 3DMAN was developed in the extension of the traditional `Stick Figure´ graphics. The program is segment-oriented and the 3-D shape of each segment is defined defined independently in a graphic model file to allow the users to use different body models with different, combinations of segments. The model file was designed easy to edit so as to allow the users to change the graphic model easily to meet their specific needs. The graphic model file can be edited using any text editor such as `EDIT´ of DOS. Once the `3-D Graphics´ option is activated followed by the registration of the graphic model files, the program draws the 3-D shapes of the segments whose model files are registered. All the graphics-related menus including registration of the segment graphic model files are accessible within the graphic environment.

Polystyrene composites containing crosslinked polystyrene-multiwalled carbon nanotube balls

Kwon, Soon-Min,Kim, Hun-Sik,Kim, Don-Young,Yun, Young Soo,Jin, Hyoung-Joon Wiley Subscription Services, Inc., A Wiley Company 2008 Journal of applied polymer science Vol.110 No.6

<P>Crosslinked polystyrene-multiwalled carbon nanotube (PS-MWCNT) balls, which act as conductive microfillers, were prepared by the in situ suspension polymerization of styrene with MWCNTs and divinyl benzene (DVB) as a crosslinking agent. The diameters of the synthesized crosslinked PS-MWCNT balls ranged from 10 to 100 μm and their electrical conductivity was about 7.7 × 10<SUP>−3</SUP> S/cm. The morphology of the crosslinked PS-MWCNT balls was observed by scanning electron microscopy and transmission electron microscopy. The change in the chemical structure of the MWCNTs was confirmed by Raman spectroscopy and Fourier transform infrared spectroscopy. The mechanical and electrical properties of the PS/crosslinked PS-MWCNT ball composites were investigated. It was found that the tensile strength, ultimate strain, Young's modulus, and impact strength of the PS matrix were enhanced by the incorporation of the crosslinked PS-MWCNT balls. In addition, the mechanical properties of the PS/crosslinked PS-MWCNT ball composites were better than those of the PS/pristine MWCNT composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008</P>

젊은 여성의 목에 발생한 탄력섬유거짓황색종양 유두진피 탄력섬유용해증

이준호 ( Joon Ho Lee ),권혁부 ( Hyok Bu Kwon ),이애영 ( Ai Young Lee ),이승호 ( Seung Ho Lee ) 대한피부과학회 2009 대한피부과학회지 Vol.47 No.4

Pseudoxanthoma elasticum-like papillary dermal elastolysis (PXE-like PDE) is a rare acquired elastolytic disorder that clinically resembles pseudoxanthoma elasticum. The pathogenesis of this disease is uncertain, but it seems to be related to intrinsic aging, abnormal elastogenesis, a genetic predisposition and exposure to ultraviolet radiation. It generally develops on the sides of the neck and supraclavicular regions in elderly persons. Histologically, the characteristic features are the loss of elastic fibers in the papillary dermis and no solar elastosis. We report here on a case of PXE-like PDE in a 26-year-old female whose skin lesion developed 9 years previously. Despite the preferential occurrence at an old age, our patient was young. (Korean J Dermatol 2009;47(4):431~434)

Fe-0.7%C-2.3%Si강의 미세조직과 기계적 성질에 미치는 잔류 오스테나이트 변태 거동

손제영 ( Je Young Son ),권도영 ( Do Young Kwon ),김지훈 ( Ji Hun Kim ),김원배 ( Won Bae Kim ),예병준 ( Byung Joon Ye ) 한국주조공학회 2012 한국주조공학회지 Vol.32 No.3

This steel has been synthesized integrating concepts from Austempering Ductile Cast Iron (ADI) technology. While ADI has excellent mechanical and physical properties, the Young`s modules of ADI is approximately 20% lower than steel. In addition, the presence of graphite nodules in ADI can be sites of crack initiation, where fracture takes place at graphite matrix interface. Because of this limitations of ADI, there has been a growing interest in austempered steels as structural materials in resent years. In this investigation, a new steel with microstructure composed of ferrite and austenite and with simultaneous high tensile strength (1,150MPa) and high ductility (33%) was developed. The goal of this investigation is to obtain a better understanding of deformation and transformation behaviour in high carbon retained austenite(γHC) and over-saturated ferrite(α) during the plastic deformation. A detailed study of the microstructure of this steel was carried out by means of X-ray diffraction (XRD) and electron back scattering diffraction (EBSD) technic. In this way it was shown that BCC phase (BCC) took up the larger part of the nominal strain whereas the a part of retained austenite responded to the mechanincal load by partial martensite transformation, and misorientation change in the retained austenite after plastic strain could be attributed to the large elongation.

Direct effectiveness of pneumococcal polysaccharide vaccine against invasive pneumococcal disease and non-bacteremic pneumococcal pneumonia in elderly population in the era of pneumococcal conjugate vaccine: A case-control study

Kim, Jong Hun,Chun, Byung Chul,Song, Joon Young,Kim, Hyo Youl,Bae, In-Gyu,Kim, Dong-Min,Choi, Young Hwa,Jun, Yoon Hee,Choi, Won Suk,Kang, Seong Hee,Kwon, Hyun Hee,Jeong, Hye Won,Kee, Sae Yoon,Hur, Jia Elsevier Ltd. 2019 Vaccine Vol. No.

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>While herd effects and serotype replacement by childhood pneumococcal protein conjugated vaccines (PCVs) continues to accumulate worldwide, direct effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPV23) against pneumococcal diseases in the elderly has been challenged. We estimated the direct effectiveness of PPV23 in the elderly population.</P> <P><B>Methods</B></P> <P>For a hospital-based case-control study, cases of invasive pneumococcal disease (IPD) and non-bacteremic pneumococcal pneumonia (NBPP) (adults ≥ 65 years) were identified in 14 hospitals participated in the pneumococcal surveillance program from March 2013 to October 2015, following implementation of PPV23 national immunization program (NIP) for the elderly in the Republic of Korea. Controls matched by age, sex, and hospital were selected at ratios of 1:2 (IPD) or 1:1 (NBPP). Clinical data and vaccination records were collected. Vaccine effectiveness was calculated as (1-adjusted odds ratio) × 100.</P> <P><B>Results</B></P> <P>We enrolled 148 IPD and 557 NBPP cases, and 295 IPD and 557 NBPP controls for analyses. Overall effectiveness of PPV23 against IPD was 28.5% [95% confidence interval (CI) −5.8%–51.6%] and against NBPP was 10.2% (-15.1-30.6) in all patients ≥ 65 years. However, in subgroup analysis of patients aged 65–74 years, PPV23 was protective against IPD [effectiveness 57.4% (19.4–77.5)] and against NBPP [effectiveness 35.0% (2.3–56.7)]. Furthermore, serotype-specific effectiveness of PPV23 against IPD was 90.6% (27.6–98.8) for PPV23-unique serotypes and 81.3% (38.6–94.3) for PPV23 serotypes excluding serotype 3.</P> <P><B>Conclusions</B></P> <P>This study indicates that PPV23 with broad serotype coverage might be beneficial in preventing IPD and NBPP due to non-PCV13 serotypes in the young-elderly, with potentially increasing effectiveness in the setting of childhood PCV NIP.</P> <P><B>Highlights</B></P> <P> <UL> <LI> National immunization program for PPV23 for the elderly was implemented in Korea. </LI> <LI> PPV23 was effective against IPD and NBPP for young elderly patients aged 65–74. </LI> <LI> Effectiveness of PPV23 against IPD was higher for PPV23 unique serotypes. </LI> <LI> PPV23 was non-protective against IPD caused by PCV13 serotypes. </LI> </UL> </P>

지방도시개발 과정에서 공공주체의 역할에 관한 연구

권준오,김영곤,김경우 朝鮮大學校 建設技術硏究所 1998 建設技術硏究 Vol.18 No.1

Since the globalization has been emphasized as one of the major policy goals of the government from 1980s, the political change of the end of cold war age has required a new international order. We have experienced the rapid economic growth and urbanization for the fast 30 years, but in the reality that the people's awareness of crisis for the changes of the recent international political and economic order and the age of localization comes in domestic condition, we have not enough time to equip with self-supporting power and the mature consciousness. Moreover, the flexible attitude that can define two urgent tasks by two wheels connected to an axis rather than consider them as the separate problems is required. Therefore, this study is to suggest what strategies the local cities under the condition that opportunity and crisis, and advantage and disadvantage coexist should develop for the globalization and how the roles of public sectors which have performed many roles as the subject of the development should be progressed in the developmental process of local cities, and then it is to help develop the globalization related projects of local cities effectively.

人文系高等學校 物理實驗의 問題點

權寧駿,趙泰璟 공주대학교 사범대학 과학교육연구소 1978 과학교육연구 Vol.10 No.1

Experiment is very important in physics education and is much so in the new curriculum of physics. Writers investigated and analyzed the status of the high school physics experiment in our nation. From the problems which was found, we do grope the improved plan for the advanced physics experiment engagement. (1)Curriculum It seems to be in correspondance with the current of modern thought, but the system of selection must be changed and the units of the physics curriculum (12 units) must be increased. (2) Laboratory facilities Laboratories, collateral facilities and experiment apparatus must be filled up, especially the teaching materials of the modern physics. (3)Experiment management More student experiments are demanded. And experiment management which is in according to the ability of the students is realized (essential, optional, extra-curriculum experiment etc). (4) Teachers In order to adapt to the new physics experiment, in-service training workshop is periodically need. And teaching condition should be improved and teacher's loadings should be reduce, and teachers could be received good payment. (5) Students An instructive and an interesting physics experiments are imposed to the student in order that the students are familiar to the physics.

유지시간 변화에 따른 크리프-피로 수명예측 방법에 관한 연구

권영일,김범준,임병수 成均館大學校 科學技術硏究所 2001 論文集 Vol.52 No.2

In this study, creep-fatigue tests were carried out under the various test conditions using AISI 316 stainless steel. Life prediction was made by three different methods which are the modified Coffin-Manson method, the modified Ostergen method and the artificial neural network method with the adaptive learning rate. The predicted lives were compared with the experimental results and following conclusions were obtained within the scope of this study. Creep-fatigue life prediction by the modified Coffin-Manson method and the modified Ostegren method had the average error of 47.3% and 50.8% respectively whereas the artificial neural network method had only 28.8% for compressive and tensile+compressive hold time. From the obtained results, the artificial neural network method with the adaptive learning rate was proved to be more accurate and effective than the other two methods. The validity of artificial neural network method for life prediction checked with 3 verification data points proved also to be very satisfactory.

全南地域의 人口指標設定 改善方案에 관한 硏究

권준오,김우혁,정영덕 조선대학교 국토개발연구소 1997 국토개발연구 Vol.17 No.1

The aim of this study is to find out appropriate solutions to various problems created by wrong applied assumption of population. And these solutions are to be applied to establishment of urban planning. Besides assuming the population of urban planning is the most important yardstick of deciding the size of future urban and physical environment. Therefore to develop the plan more efficiently, I suggest these as followings. First of all, the mathematical methods which is proper to the characteristics of urban must be applied and produced through the outlook based on analysis of natural population, such as birth, death, transference in the past. Secondly, the moving in population of society must be limited on the target year. Thirdly, the population division plan by regional groups must be proceeded. The last but not least, the examination and evaluation on population plan must be performed.