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      • Development of a Mobile Application, "Wild Flowers of Bukhansan National Park (version 1.0)", for Identification of Plants in Bukhansan National Park

        Kim, Sang-Tae,Lee, Seung-Yeon,Kim, Seung-Chul,Byun, Hye-Won,Lee, Sang-Tae,Kim, Mu-Yeal,Hong, Seok-Pyo,Chung, Young-Jae,Park, Ki-Ryong,Lee, Chung-Hee,Lee, Joong-Ku,Heo, Kyeong-In,Lee, Ji-Ye,Lee, Eun-Je National Science Museum of Korea 2011 Journal of Korean nature Vol.4 No.3

        We developed the educational purpose mobile application, named "Wild Flowers of Bukhansan National Park (version 1.0)", aiming for easy identification of wild flowers for students and visitors in the park. When visitors find a flower or part of plant in the park, visitors can search for its name utilizing the pictures and characters provided in their own smartphone mobile devices or tablet PCs. The application provides pictures of wild flowers in the park and character-based searching system based on 12 diagnostic features (e.g., growth form, leaf arrangement, flower symmetry, petal color, petal number, sepal number, etc). We adopted the complete floristic survey of Chung and Lee (1962) and added species that we confirmed their distribution in the park during the development of this application. In summary, number of vascular plants in this park was estimated to be 428 taxa including 100 families, 280 genera, 327 species, 1 subspecies, 50 varieties, and 5 formas. We provided a total of 588 pictures representing 358 taxa and each taxon includes multiple pictures in many cases. Included identification quizzes can be an efficient educational tool as well as fun activity for students and visitors who are learning plant species in Korea. Our next step will include GPS function in the application for indicating visitor's location and for providing previously reported sites of the species that we interested in the map of the park. The future application which includes GPS function will be a valuable tool for the monitoring of rare plants, plant researches related to the climate changes, etc. We currently provide Korean iPhone version only, and English version and both of android versions will be serviced soon.

      • SCOPUSKCI등재

        한국인 폐확산능 정상예측식의 임상적 유용성과 정확성

        나승원 ( Seung Won Ra ),박태선 ( Tai Sun Park ),홍윤기 ( Yoon Ki Hong ),홍상범 ( Sang Bum Hong ),심태선 ( Tae Sun Shim ),임채만 ( Chae Man Lim ),이상도 ( Sang Do Lee ),고윤석 ( Youn Suck Koh ),김우성 ( Woo Sung Kim ),김동순 ( Dong 대한결핵 및 호흡기학회 2008 Tuberculosis and Respiratory Diseases Vol.64 No.2

        연구배경: 폐확산능을 해석하는 데 필요한 정상예측식으로는 한국인을 대상으로 하여 박 등이 개발한 식(박 식)이 있으나 아직 외국 정상예측식을 많이 사용하고 있다. 이에 국내에서 많이 사용하는 외국 정상예측식인 Burrows 식과 박 식의 임상적 유용성과 정확성을 비교하고자 하였다. 방법: 1. 임상적 유용성 연구; 2006년 7월부터 12월까지 6개월간 폐확산능검사를 시행한 환자 중 두 식을 각각 정상예측식으로 적용하였을 때 폐확산능 해석이 다른 276명(대상군 A)을 대상으로 하였다. 대상군 A에게 두 식을 각각 적용하였을 때 폐확산능 해석과 임상적 판단과의 일치도를 비교하여 임상적 유용성을 평가하였다. 2. 간질성폐질환 진단의 정확성 비교; 2001년부터 2006년까지 폐조직검사를 시행하여 확진된 간질성폐질환군과 서울아산병원에서 모집한 정상군을 대상으로 하여 정상예측식으로 두 식을 각각 적용하였을 때 폐확산능 해석의 정확도를 비교하였고, 두 식이 차이가 나는지 맥니머의 카이스퀘어 검정을 하였다. 결과: 1. 임상적 판단과의 일치도 비교; 276명을 임상정보를 토대로 폐확산능을 예측하여 분류한 결과 정상 54명, 감소 220명, 불분명이 2명이었다. 예측식으로 박 식과 Burrows 식을 적용하였을 때 임상적 판단과 일치하는 환자는 각각 78%와 22%이었다(p<0.001). 2. 간질성폐질환 진단의 정확성 비교; 박 식은 민감도 90.1%, 특이도 100%이었고 Burrows 식은 민감도 64.2%, 특이도 100%로 민감도가 통계학적으로 유의하게 박 식이 높았다(p<0.001). 결론: 우리나라 정상예측식인 박 식이 외국 정상예측식인 Burrows 식을 정상예측식으로 적용하는 것보다 임상적 유용성이나 간질성폐질환 진단의 민감도에서 더 우월하였다. 향후 폐확산능검사의 정상예측식으로 박 식을 사용해야 할 것으로 사료된다. Background: Park et al. developed the Korean reference equation for the measurement of diffusing capacity in 1985. However, the equation has not been widely used in Korea and foreign reference equations have been popularly used. We intended to compare the clinical usefulness and the accuracy of the the Korean reference equation (Park`s equation) with that of the foreign equation (Burrows` equation) that is commonly used in Korea. Methods: 1. Evaluation of clinical usefulness; Among 1,584 patients who underwent diffusing capacity (DLCO) at the Asan Medical Center from July to December 2006, group A subjects included 276 patients who had different interpretations of DLCO in trials employing Burrows` equation and Park`s equation. Clinical assessment was decided by consensus of two respiratory physicians. In order to evaluate the clinical usefulness of Burrows` equation and Park`s equation, agreement of clinical assessment and DLCO interpretation were measured. 2. Evaluation of accuracy; Group B subjects were 81 patients with interstitial lung disease (ILD) and 39 normal subjects. The 81 ILD patients were diagnosed following a surgical lung biopsy. The accuracy of diagnosing ILD as well as sensitivity and specificity were evaluated according to the use of the reference equations (Burrows` equation and Park`s equation) for DLCO. Results: Agreement between clinical assessment and interpretation of DLCO was 22% for the use of Burrows` equation and 78% for the use of Park`s equation. The sensitivity and specificity of the Burrows` equation for diagnosing ILD were 64.2% and 100%. The sensitivity and specificity of the Park`s equation for diagnosing ILD were 90.1% and 100%. The sensitivity of the Park`s equation for diagnosing ILD was significantly higher than that of Burrows` equation (p<0.001). Conclusion: The Korean reference equation (Park`s equation) was more clinically useful and had higher sensitivity for diagnosing ILD than the foreign reference equation (Burrows` equation). (Tuberc Respir Dis 2008;64:80-86)

      • KCI등재

        한국 국립공원 산림생태계의 수목 탄소저장량 평가

        이상진,박홍철,박관수,김현숙,이창민,김진원,심규원,최승운,Lee, Sang-Jin,Park, Hong-Chul,Park, Gwan-Soo,Kim, Hyoun-Sook,Lee, Chang-Min,Kim, Jin-Won,Sim, Gyu-Won,Choi, Seung-Woon 한국환경복원기술학회 2022 한국환경복원기술학회지 Vol.25 No.3

        The purpose of this study is to quantitatively evaluate the amount of carbon storage for trees in forest ecosystem to support the foundation for carbon neutrality implementation in Korea National Park. It targeted 22 national parks designated and managed as national parks in Korea, and conducted research on forest trees in the terrestrial ecosystem among various natural and ecological carbon sink. The survey and analysis method followed the IPCC guidelines and the National Greenhouse Gas Inventory in Korea. The amount of tree carbon storage in the forest ecosystem of Korea National Park was confirmed to be about 218,505 thousand CO<sub>2</sub>-ton and the amount of carbon storage per unit area was 570.8 CO<sub>2</sub>-ton per hectare. Compared to 299.7 CO<sub>2</sub>-ton per hectare, the average carbon storage per unit area of the entire Korean forest, it was found that about twice as much carbon was stored when assuming the same area. In other words, it means that the tree carbon storage function of the national park is about twice as high as that of the average tree carbon storage function of entire Korean forest. It has great implications in Korea National Park not only provides biodiversity promotion and exploration services as a national protected area, but also performs excellent functions as a carbon sink.

      • 도시소공원 이용행태 및 만족도 평가 : 서울시 도시소공원을 중심으로 Focused on Vest Pocket Parks in Seoul

        박원규,김유일,안진성 호남대학교산업기술연구소 2002 산업기술연구논문집 Vol.10 No.-

        The purpose of this study is to obtain the actual data about human activities responding to physical environments of the 'Vest Pocket Park' and to provide fundamental data in planning the small pocket park. The method of this study was based on multi-method such as on-the-spot, documents, interviews and questionary investigations. Questionnaires were given to the randomly selected users of the Vest Pocket Parks, and were designed by several sets of variable, such as behavioral patterns, satisfaction and value of users. The data was analyzed by descriptive statistics analysis. The main result of this study can be summarized as follows ; The users of Vest Pocket Parks are mainly young employees and students, and they stay at with in one hours as relative short time. The factors that affect to satisfaction of park are 'amount of green-spaces', 'amount of sunlight', 'suitablilty for seating and talking', 'privacy', 'harmonizing with surrounding', 'visual interesting of landscape of park'.

      • 圓光醫大 附屬 第2病院 神經精神科 患者에 對한 統計的 考察(Ⅱ)

        박민철,장광철,김상원,김한주,유미경,김훈,유용진,김현정,박남진,오상우,이귀행,노승호,백영석 圓光大學校 醫科大學 神經精神科學敎室 1992 圓光精神醫學 Vol.8 No.1

        본 연구는 1986년 7월 11일부터 1991년 7월 10일까지 원광의대 부속 제2병원 신경정신과에서 의래 및 입원치료를 받았던 6,072명의 환자를 대상으로 병원 역학조사를 실시하고 그 결과를 1차조사 (박민철 등1986)와 비교했다. 1.전체 환자 중 남자가 54.4%로 여자보다 많았고, 이리와 이리 인접지역이 84.0%로 대부분의 지역을 나타났다. 의료보장상태는 보험환자가 57.1%, 의료보호환자21.8%, 일반환자 21.1%였으며 연령별로는 20대 24.6%, 30대 22.8%로 20대 30대가 절반정도를 차지했다. 2.외래환자에서는 신경중성장애가 46.0%로 가장 많고 정동장애, 경련성장애 순이며, 입원환자에서는 정신분열증이 30.5%로 가장 많고 기질성정신장애, 정동장애의 순이었다. 3.남자는 신경증성쟝애(23.4%), 정신분열증, 기질성정신장애 순이고 여자는 신경증성장애(39.9%), 정동장애, 정신분열증의 순이었다. 남자가 여자보다 많은 진단은 알코올정신장애(94.6%), 기질성정신장애, 소아정신장애 순이고, 여자가 남자보다 많은 진단은 정동장애(64.5%), 신경증성장애였다. 4.진단별 연령분포에서 신경증성장에는 30대(25.3%), 20대, 40대 순이고, 정신분열증은 20대(40.5%), 30대, 40대 순이며, 정동장애는 20대, 30대, 50대 순이나 비교적 비슷한 융이었다. 5.진단별 발병연령에서 신경증성장에는 20대, 30대가 절반이고,정신분열증은 20대(51.3%), 10대, 30대 순이며 정동장애는 20대(30.7%), 30대, 50대 순이었다. 진단별 평균 발병연령은 신경증성장애 32.7세, 정동장애 36.1세, 정신분열증 23.6세였다. 6.진단별 이병기간은 2년이상이 신경증성장에 28.3%, 정신분열증 68.5% 정동장애 43.9%인데 전체적으로 41.0%였다. 진단별 평균 이병기간은 정신분열증 73.2개월, 정동장애 45.5개월, 신경증성장애 29.5개월이었다. We examined epidemiologic study of 6,072 patients who visited Wonkwang Neuropsychiatric hospital since July 11 of 1986 until July 10 of 1991 and compared this results with previous study(Park et al 1986). The study revealed as follows:1. Of total patients males visited this hosptial more than females as 57.1%, Most of them(84.0%) resided Iri and neighbouring Iri. In the point of insurance, insured patients, medicaid patients and uninsured patients were 57.1%, 21.8% and 21.1% respectively. On the distribution of age, the twenties, the thirties were 24.6%, 22.8% respectively and twenties and thirties were about half of total patients. 2. Of outpatients neurotic disorder was the most as 46.0%, secondly mood disorder and thirdly convulsive disorder, but of inpatients schizophrenia was the most as 30.5%, secondly organic mental disorder and thirdly mood disorder. 3. Of males neurotic disorder was the most as 23.4%, secondly schizophrenia, and thirdly organic mental disorder, but of females neurotic disorder was the most as 39.9%, secondly mood disorder and thirdly schizophrenia. alcoholic mental disorder(94.6%), organic mental disorder, child mental disorder were mostly found in males,but mood disorder(64.5%) and neurotic disorder were mostly found in females. 4. On the distribution of age neurotic disorder was found the most in the thirties(25.3%), next in the twenties and in the forties, and schizophrenia was found the most in the twenties(40.5%), next in the thirties and in the forties, but mood disorder was found the most in the twenties, next in the thirties and in the forties but revealed similar rates relatively. 5. On the distribution of age of onset neurotic disorder developed nearly half during the twrnties and the thirties, schizophrenia developed mostly during the twenties (51.3%), secondly the teens and thirdly the thirties, but mood disorder developed firstly the twenties(30.7%), secondly the thirties and thirdly the fifties. on the average age of onset of illness neurotic disorder, mood disorder and schizophrenia were 32.7 years, 36.1 years and 23.6 years respectively. 6. On the duration of illness more than two years was 28.3% in neurotic disorder, 68.5% in schizophrenia and 3.9% in mood disorder and on the average duration of illness schizophrenia, mood disorder and neurotic disorder were 73.2 months, 45.5 months and 29.5 months respectively.

      • KCI등재후보

        다기관 기능부전을 초래한 치명적인 삼일열 말라리아 증례

        박상원,김동우,박주원,이순일,신영학,김의종,오명돈,최강원 대한감염학회 2005 감염과 화학요법 Vol.37 No.2

        삼일열 말라리아는 국내에서 재유행하고 있는 감염질환으로, 일반적으로 양성의 임상경과를 거친다. 저자들은 특이한 질병력이 없이 건강하였던 젊은 성인이 국내에서 삼일열 말라리아에 걸린 후 다기관기능부전과 폐출혈으로 사망한 증례를 경험하였다. 환자의 중증 임상경과를 설명할 만한 특이한 인자가 발견되지 않았다. Vivax malaria is a re-emerging infectious disease in Korea with cumulating 19,416 cases as of December 2003 since 1993. Vivax malaria is generally a benign disease with few severe complications. Even in the worldwide literature, there are only small number of case reports on severe complications. We experienced a fatal vivax malaria in a previously healthy young adult with severe multi-organ failure and fatal massive pulmonary hemorrhage. The patient presented with abdominal pain and shock. There were splenic hemorrhage, disseminated intravascular coagulation, oliguric acute renal failure requiring dialysis, and pulmonary hemorrhage leading the patient finally to death. The initial parasitemia was 2,046/μL. Thin smear and PCR revealed only Plasmodium Vivax. There was no explainable cause of death except for the only serological suggestion of Mycoplasma pneumoniae infection without correlating clinical evidence. This is a first case of fatal vivax malaria in Korea since its re-emergence in 1993. Further case monitoring is needed to define whether this is a index case or an isolated one.

      • KCI등재후보

        광조사 방식이 복합레진의 중합과 누출에 미치는 영향

        박종진,박정원,박성호,박주명,권태경,김성교 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.2

        The aim of this study was to investigate the effect of light irradiation modes on polymerization shrinkage, degree of cure and microleakage of a composite resin. VIP^™ (Bisco Dental Products, Schaumburg, IL, USA) and Optilux 501^™(demetron/ Kerr, Danbury, CT, USA) were used for curing Filtek^™ Z-250(3M Dental Products, St. Paul., MN, USA) composite resin using following irradiation modes: VIP^™ (Bisco) 200mW/cm^2 (V2), 400mW/cm^2 (V4), 600mW/cm^2 (V6), Pulse-delay (200 mW/cm^2 3 seconds, 5 minutes wait, 600mW/cm^2 30seconds, VPD) and Optilux 501^™ (Demetron/Kerr) C-mode (OC), R-mode (OR). Linear polymerization shrinkage of the composite specimens were measured using Linometer (R&B, Daejeon, Korea) for 90 seconds for V2, V4, V6, OC, OR groups and for up to 363 seconds for VPD group (n=10, each). Degree of conversion was measured using FTIR spectrometer (IFS 120 HR, Bruker Karlsruhe, Germany) at the bottom surface of 2 mm thick composite specimens. V2, V4, V6, OC groups were measured separately at five irradiation times (5, 10, 20, 40, 60 seconds) and Or, VPD groups were measured in the above mentioned irradiation modes (n=5, each). Microhardness was measured using Digital microhardness tester (FM7, Future-Tech Co., Tokyo, Japan) at the top and bottom surfaces of 2mm thick composite specimens after exposure to the same irradiation modes as the test of degree of conversion(n=3, each). For the microleakage test, class V cavities were prepared on the distal surface of the ninety extracted human third molars. The cavities were restored with one of the following irradiation modes: V2/60 seconds. V4/40 seconds, V6/30 seconds, VPD, OC and OR. Microleakage was asessed by dye penetration along enamel and dentin marigns of cavities. Mean polymerization shrinkage, mean degree of conversion and mean microhardness values for all groups at each time were analyzed using one-way ANOVA and Duncan's multiple range test, and using chisquare test for microleakage values. The results were as follows: ·Polymerization shrinkage was increased with higher light intensity in groups using VIP^™(Bisco) : the highset with 600mW/cm^2, followed by Pulse-delay, 400mW/cm^2 and 200mW/cm^2 groups. The degree of polymerization shrinkage was higher with Continuous mode than with Ramp mode in groups using Optilux 501^™ (Demetron/Kerr). ·Degree of conversion and microhardness values were higher with higher light intensity. The final degree of conversion was in the range of 44.7 to 54.98% and the final microhardness value in the range of 34.10 to 56.340. ·Microleakage was greater in dentin margin than in enamel margin. Higher light intensity showed more microleakage in dentin margin in groups using VIP^™ (Bisco). The microleakage was the lowest with Continuous mode in enamel margin and with Ramp mode in dentin margin when Optilux 501^™ (Demetron/Kerr) was used.

      • KCI등재후보

        대량의 각혈로 사망한 장티푸스 1예

        한상우,유진홍,권순석,김성훈,박지찬,홍은정,최경성,박용완,장준희,안지원,박유경,강지영,박상미,신완식 대한감염학회 2004 감염과 화학요법 Vol.36 No.5

        We experienced a 25 year-old male patient with typhoid fever complicated with massive hemoptysis. Pulmonary complication in typhoid fever is very rare and to our knowledge, there has been no report of hemoptysis as a main cause of death with this disease. We herein report a rare case of typhoid fever.

      • 도시근린공원의 편익비용분석 : 청주시를 대상으로 A Case of Chongju

        권상준,명현,박구원,이만희 청주대학교 산업과학연구소 1993 産業科學硏究 Vol.11 No.-

        As a consequence of this study, the analyses of urban community parks in Chongju are as follows; 1. The total benefit of three scenarios can be calculated at 200,031, 255,197, 368,411 million Won, respetively depending on the scenario, which of the percentage of indirect benefit is 57.7%, 49.3%, 53.3% respetively in the order of the scenario . 2. The total cost can be calculated at 231,840 million Won. 3. The ratio of Benefit and Cost comes out in the order of the scenario 3, 2, 1, depending on the relative importance factors according to the benefit. 4. The priority of developing community parks depends on the hiearchical order factors: location, developed area, scale of parks.

      • KCI등재

        운동훈련이 흰쥐 노화심근에 미치는 영향

        박원학(Won-Hark Park),이상선(Sang-Sun Lee),이용덕(Yong-Deok Lee) 대한의생명과학회 1996 Biomedical Science Letters Vol.2 No.1

        장기간 반복 주행운동이 흰쥐의 심근에 미치는 효과를 규명하기 위하여 생후 3개월, 10개월 및 20개월된 흰쥐를 운동군과 대조군으로 대별하여 motor driven treadmill을 이용하여 Park등이 사용한 방법에 준해서 5개월만, 주 5일 20분간 운동을 시킨 후 심근의 조직 및 세포학적 변화를 관찰하고 심근 세포 내 미세구조 변화를 입체해석학적으로 비교 분석하였다. 연령 증가에 따라 장기간 반복운동이 흰쥐 심근 미세구조에 미치는 영향은, 8, 15개월의 운동군과 대조군 사이에 뚜렷한 차이를 인정할 수 없으며, 15개월의 운동군에서 대조군에 비하여 변성된 사립체, 리소조옴, 지방적, 공포, 노화색소 등이 증가하는 경향이 있었다. 25개월 운동군은 같은 연령 대조군에 비하여 근원섬유 수축대, 근원섬유 소실, 윤반분리, 세포간질 증식, 핵의 변성, 교원섬유 근섬유내 침입 등 매우 심한 변화를 보였다. 조직상에 나타나는 early lipofusin과 미세구조상에 나타나는 노화색소는 8, 15개월의 운동군과 대조군 사이에 유의한 차이는 없었으며, 25개월 운동군은 같은 연령 대조군에 비하여 유의한 차이로 증가하였다. Glucose-6-phosphatase 활성도 8, 15개월군에서 운동군과 대조군에서 모두 활성이 높았으며 25개월의 대조군과 운동군에서는 모두 활성이 거의 나타나지 않았다. 미세구조 변화를 입체해석학적으로 분석한 결과 8, 15개월의 대조군과 운동군에서 체적 밀도의 모든 항은 양군 사이에 유의한 감소를 나타내었고 근형질세망의 체적밀도는 감소하는 경향을 보였다. 사립체는 대조군에 비하여 유의한 감소를 나타내었고 근형질세망의 체적밀도는 감소하는 경향을 보였다. 사립체와 근원섬유 비는 8개월 운동군에서 유의한 차이는 없지만 대조군에 비하여 높게 나타났으며, 15개월의 운동군과 대조군 사이에서는 차이를 인정할 수 없었다. 그러나 25개월 운동군은 대조군에 비하여 유의한 차이로 감소하였다. 연령증가에 따른 사립체 내막 표면밀도와 사립체수는 대조군과 운동군 사이에는 유의한 변화는 없었다. 본 연구의 성적을 검토한 결과 젊은층(3개월군)과 중령층(10개월군)의 흰쥐에서는 반복된 지구력 운동이 심장에 미치는 역효과를 인정할 수 없었으며 젊은층의 흰쥐에서는 오히려 심장기능 강화를 보이는 경향이 나타났으며, 노화층(20개월군)에서 운동군에서는 스트레스로 작용하여 심장기능의 저하를 초래 하였다고 생각된다. There is considerable current interest in the effect of regular vigorous exercise and in particular endurance-running as a possible measure in improving myocardial function. Some data indicate that the aging heart may actually suffer from vigorous endurance exercise. On the contrary, appropriate exercise in aged animals improves myocardial function and aerobic energy metabolism. So far there is relatively little data to indicate that endurance exercise is in fact beneficial in improving myocardial function or damaging to heart of aged animals. The present investigation aimed to study the possible effect of a long range treadmill training program on the heart in aging rats. Male rats aged 3, 10, and 20 months were divided at random into a control (sedentary) and an exercise group. The training group was exercised for 5 days a week on an automated treadmill for 20minutes at 18m/min over a period of 5 months. The exercise regimen of our experiments did not cause any significant changes in the tissues and ultrastructural as compared with sedentary age-matched control. Tissues and ultrastructures of myocardial cells in trained group aged 8 months are intact and well organized as well as sedentary control group. Age associated tissue and ultrastructural changes of trained group aged 15 months included : an increase in transformed mitochondria, vacuoles, lysosomes, lipid droplets and early lipofuscin. But the trained heart did not show significant difference in tissue and ultrastructural properties from those of sedentary controls. Endurance-trained group aged 25 months showed significant qualitative tissue and ultrastructural difference as compared with age-matched controls. In addition to those found in 25 months control group, focal necrosis, myofibril fraying, hypercontraction band, seperation of intercalated discs, degenerating nucleus and infiltration of collagenous fiber into myocyte were noted in trained 25 months group. The stereological examination of the micrographs disclosed no significant difference in the myofibril, mitochondrion, sarcotubule and interstitium volume density and surface density of mitochondrial cristae and numerical density of mitochondria between trained and control group aged 8 and 15 months. In the trained 25 months group, significant increase in volume density of interstitium, lipofucsin granule were shown as compared to untrained age-matched control. On the other hand, significant decrease in mitochondrion volume density was shown. The myofibril volume density did not differ between trained and control group although trained group showed slight increase. From the data obtained, a reduced mitochondria/myofibrils ratio was found in trained rat heart aged 25 months and there was no difference between trained and control rat aged 15 months. But a slight but not significant increase was found in the trained group aged 8 months as compared with same age control group. Such increase in the ratio in young animals is considered to be of great importance to cardiac pumping and adaptability. Whereas such adaptations don't seem to occur in aged heart muscle. This study proposed that repeated endurance exercise do not cause any significant qualitative and quantitative ultrastructural change of heart muscle in young(3months) and adult(10months) suggesting that the heart is able to adapt to the exercise. On the contrary, the repeated endurance exercise stress may actually induce degenerative changes in the aged heart muscle(20months).

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