• Title/Summary/Keyword: TISSUE STRESS STATE

Search Result 46, Processing Time 0.035 seconds

A Study on the Automatic Diagnosis of ECG

  • Jeong, Gu-Young;Yu, Kee-Ho;Kwon, Tae-Kyu;Lee, Seong-Cheol
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.55.4-55
    • /
    • 2001
  • Analyzing the ECG signal, we can find heart disease. Myocardial ischemia is a disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. Myocardial ischemia is inscribed on ST-segment of the ECG during and after patient takes exercise or is under stress, but after long time past, the ECG pattern is return to steady state. Therefore, it is necessary to monitor and analyze the ECG signal continuously for patient or aged people. Our primary purpose is the detection of temporary change of the ST-segment of ECG automatically. In the signal processing, the wavelet transform decomposes the ECG signal into high and low frequency components using wavelet function. Recomposing the high frequency bands including QRS complex, we can detect QRS complex more easily ...

  • PDF

A Study on the Tissue Response and Bone Formation after Augmentation Using Proplast and Porous Polyethylene in Rabbit Mandible (Proplast와 Porous Polyethylene을 이용(利用)한 가토(家兎) 하악골(下顎骨) 증대술후(增大術後) 조직반응(組織反應) 및 골형성(骨形成)에 관(關)한 연구(硏究))

  • Kim, Geon-Jung;Ryu, Sun-Youl
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.11 no.1
    • /
    • pp.101-116
    • /
    • 1989
  • Proplast and Porous Polyethylene which have porous structures as low-modulus polymers have been recently used in maxillofacial plastic and reconstructive surgery. The purpose of this study was to compare the response of adajacent tissue, new bone formation and stability after augmentation by differen methods of subperiosteal graft using proplast and purous polythylene in rabbit mandible. The augmentation procedure was carried out by dividing into two groups, A and B. A group consisted of subperiosteal graft on the cortex, and the other B group was made up only graft following artificial decortication in the mandibular body of rabbit. The experimental animals were sacrificed on the 1st, 2nd, 4th and 8th week after grafting for macroscopic and light microscopic examination. The samples extracted at the 6th postgrafting week were also used for biometric testing and scanning electron microscopic examination. The results obtained from this study were as follows : 1. Macroscopically, infection of graft site, deformation and migration of graft material were not observed in all experimental groups. 2. B group showed more rapid and increased bone formation and the greater stability than A group, and tissue response was similar to each other. 3. In the tissue response, macrophages and cellular infiltrations were observed in Proplast group, but few in PHDPE group. 4. In bone formation of A group, Proplast group showed no bone formation until the 8th week, but PHDPE group showed small quantity of osteoid tissue from the 2nd week and appositional bone growth with new bone formation at the 8th week. 5. In bone formation of B group, both Proplast and PHDPE group showed bone formation, but PHDPE group showed more rapid and larger bone formation. 6. In pattern of bone formation, Proplast group mainly showed appositional bone growth pattern connected with graft site. On the other hand, PHDPE group showed mixed pattern of new bone formation in the pore connective tissue with appositional bone growth from graff site. 7. The maximum mean values of shear stress were serially $111.3gf/mm^{2}$ in PHDPE of B group, $84.8gf/mm^{2}$ in PHDPE of A group, $32.9gf/mm^{2}$ in Proplast B group, and $15.7gf/mm^{2}$ in Proplast of A group. From above results, It was suggested that the capacity of bone formation and stability between bone and graft material were dependent on the pore size and structure of graft material itself, the state of graft site and tissue response.

  • PDF

Investigation of the efficacy of mycotoxin-detoxifying additive on health and growth of newly-weaned pigs under deoxynivalenol challenges

  • Holanda, Debora Muratori;Kim, Sung Woo
    • Animal Bioscience
    • /
    • v.34 no.3_spc
    • /
    • pp.405-416
    • /
    • 2021
  • Objective: This study evaluated the effects of feeding diets naturally contaminated with deoxynivalenol (supplemental 2 mg/kg) on health, growth, and the effects of a mycotoxin-detoxifying additive in newly-weaned pigs. Methods: Thirty-six pigs (27 day-old) were housed individually and assigned to 3 treatments for 5 weeks: CON (diet containing minimal deoxynivalenol), MT (diet with supplemental 1.9 mg/kg of deoxynivalenol), and MT+D (MT + mycotoxin-detoxifying additive, 0.2%, MegaFix, ICC, São Paulo, Brazil). The mycotoxin-detoxifying additive included bentonite, algae, enzymes, and yeast. Blood was taken at week 2 and 5. Jejunal tissue were taken at week 5. Data were analyzed using the MIXED procedure of SAS. Results: Pigs fed MT+D tended to have decreased (p = 0.056) averaged daily feed intake during week 1 than MT. At week 2, serum aspartate aminotransferase/alanine aminotransferase in MT tended to be lower (p = 0.059) than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating hepatic damages in MT and recovery in MT+D. Pigs fed MT had lower (p<0.05) blood urea nitrogen/creatinine than CON, supporting hepatic damage. At week 5, pigs fed MT tended to have reduced (p = 0.079) glucose than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating impaired intestinal glucose absorption in MT, which was improved in MT+D. Pigs fed CON tended to have increased (p = 0.057) total glutathione in jejunum than MT, indicating oxidative stress in MT. Pigs fed MT+D had a reduced (p<0.05) proportion of Ki-67-positive cells in jejunum than MT, indicating lower enterocyte proliferation in MT+D. Conclusion: Feeding supplemental 1.9 mg/kg of deoxynivalenol reduced growth and debilitated hepatic health of pigs, as seen in leakage of hepatic enzymes, impaired nitrogen metabolism, and increase in oxidative stress. The mycotoxin-detoxifying enhanced hepatic health and glucose levels, and attenuated gut damage in pigs fed deoxynivalenol contaminated diets.

Effects of Climate and Human Aquatic Activity on Early Life-history Traits in Fish (기후변화와 수상레저활동 인구변화가 어류의 초기생활사에 미치는 영향)

  • Lee, Who-Seung
    • Korean Journal of Ecology and Environment
    • /
    • v.46 no.3
    • /
    • pp.395-408
    • /
    • 2013
  • Environmental condition can induce changes in early life-history traits in order to maximise the ecological fitness. Here I investigated how temperature change and variation in human aquatic activity/behaviour affect early life-history consequences in fish using a dynamic-state-dependent model. In this study, I developed a general fish's life-history model including three life-history states depend-ing on foraging activity, such as body mass, mass of reproductive tissue (i.e., gonadal development) and accumulated stress (i.e., cellular or physiological damage). I assumed the level of foraging activity maximises reproductive success-ultimately, fitness. The model predicts that growth rate, development of reproductive tissues and damage accumulation are greater in higher temperature whereas higher human aquatic activity rapidly reduced the growth rate and development of reproductive tissue and increased damage accumulation. While higher foraging activity in higher temperature is less affected by human aquatic activity, the foraging activity in lower temperature rapidly declined with human aquatic activity. Moreover, lower survival rate in higher temperature or human aquatic activity was independent on mortality rate due to human aquatic activity or mortality rate when foraging activity, respectively. However, the survival rate in lower temperature or human aquatic activity was dependent on these mortality rates. My findings suggest that including of early life-history traits in relation to climate-change and human aquatic activity on the analysis may improve conservation plan and health assessment in aquatic ecosystem.

Evaluation of Stress Characteristics and Rupture Risk of the Aortic Wall According to Abdominal Aortic Aneurysm Geometry and Age (복부대동맥류 형상 및 연령에 따른 동맥 벽 응력 특성 및 파열 위험성 평가)

  • Lee, Chung Won;You, Ji-Hun;Huh, Up;Lee, Chi-Seung;Ryu, Dong-Man
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.33 no.3
    • /
    • pp.179-186
    • /
    • 2020
  • In this study, the wall stress and rupture risk for abdominal aortic aneurysms were calculated based on the age and geometry of the examined abdominal aortic aneurysms. The geometry of the abdominal aorta was simulated using computed tomography data from patients with abdominal aortic aneurysms. With regard to material properties, the Gasser-Ogden-Holzapfel model was applied to the analysis to simulate the anisotropic hyperelastic characteristics of the artery. In addition, each material parameter was estimated to consider the properties for age and for normal and aneurysm tissue. Moreover, the correlation between the diameter and angle of the aortic aneurysms was analyzed based on data from patients with abdominal aortic aneurysms, and series simulations were conducted. As a result, the rupture risk for the abdominal aortic aneurysms was evaluated based on the age and geometry of the aneurysm.

Effect of Se-methylselenocysteine on the Antioxidant System in Rat Tissues

  • Shin, Ho-Sang;Choi, Eun-Mi
    • Preventive Nutrition and Food Science
    • /
    • v.15 no.4
    • /
    • pp.267-274
    • /
    • 2010
  • We assessed the effect of Se-methylselenocysteine (MSC) treatment, at a dose of 0.75 mg/rat/day for 1 or 2 weeks, on the activities of antioxidant systems in Sprague-Dawley rat tissues. Significant changes in glutathione and antioxidant enzyme activities, with different patterns among tissues, were evidenced. Glutathione content and its reduction state in the liver, lung, and kidney were elevated upon MSC treatment, whereas they were significantly lowered in the spleen. Among the tissues exhibiting glutathione increase, there were different enzymatic responses: $\gamma$-glutamylcysteine ligase activity, the rate-limiting enzyme in the glutathione synthesis pathway, was increased in the liver, whereas the activities of the enzymes associated with glutathione recycling, namely, glutathione peroxidase, glutathione reductase, and glucose 6-phosphate dehydrogenase, were significantly increased in the lung and the kidney. The superoxide dismutase activity was decreased in all tissues upon MSC treatment, whereas catalase activity was increased in all tissues but the liver. Lipid peroxidation level was transiently increased at 1 week in the lung and the kidney, whereas it was persistently increased in the spleen. The increase was not evident in the liver. The results indicate that the MSC treatment results in an increase in the antioxidant capacity of the liver, lung, and kidney principally via an increase in glutathione content and reduction, which appeared to be a result of increased synthesis or recycling of glutathione via tissue-dependent adaptive response to oxidative stress triggered by MSC. The spleen appeared to be very sensitive to oxidative stress, and therefore, the adaptive response could not provide protection against oxidative damage.

The effect of phosphorus stress on the energy status and bacteroid content in soybean nodules (인산결핍이 대두근류의 bacteroid 함량과 energy 상태에 미치는 영향)

  • Sa, Tong-Min;Lim, Sun-Uk;Israel, Daniel W.
    • Applied Biological Chemistry
    • /
    • v.35 no.6
    • /
    • pp.449-456
    • /
    • 1992
  • Expermient were conducted to determine the effect of phosphorus stress on bacteroid content and energy status of soybean (Glycine max [L.] Merr.) nodules. Plants inoculated with Bradyrhizobium japonicum MN 110 were grown with P-stressed (0.05 mM-P) and control (1 mM-P) treatment in the greenhouse. Phosphorus stress decreased nodule mass per plant and nodule mass to whole plant mass ratio. Phosphorus concentration in leaf, stem and root tissues were reduced by 75% but in nodule tissue was reduced only by 40% under phosphorus stress during 3 week experimental period. The bacteroid content per unit nodule mass and the distribution of total nitrogen and total phosphorus among the bacteroid and plant cell fractions of nodule were not affected significantly by phosphorus stress. Regardless of phosphorus treatment, 22% of the nitrogen and 27% of the phosphorus in whole nodules were associated with the bacteroid fraction. The ATP and total adenylate concentrations in and energy charge of whole nodule were decreased 77%, 46% and 37%, respectively, by phosphorus stress. The ATP concentration in and energy charge of the host plant cell fraction of nodules were decreased 86% and 59%, respectively, but these parametres in bacteroid in nodules were not affected by phosphorus stress. These results indicated that nodule is a strong phosphorus sink and that nodule growth and development are regulated to maintain a high phosphorus and energy content in bacteroid even when the host plant is subjected to phosphorus deficiency.

  • PDF

Plasma, Tissue Thiobarbituric Acid Reactive Substance and Lymphocyte Oxidative DNA Damage in Mouse Fed Gamma Irradiated Diet (방사선 조사 사료를 섭취한 Mouse의 혈장, 간, 소장 점막의 과산화지질과 림프구 DNA의 산화적 손상)

  • 장현희;강명희;양재승;이선영
    • Journal of Nutrition and Health
    • /
    • v.36 no.3
    • /
    • pp.255-261
    • /
    • 2003
  • Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.

Constitutive Model of Tendon Responses to Multiple Cyclic Demands(I) -Experimental Analysis-

  • Chun, Keyoung-Jin;Robert P. Hubbard
    • Journal of Mechanical Science and Technology
    • /
    • v.15 no.7
    • /
    • pp.1002-1012
    • /
    • 2001
  • The work reported here is an extensive study of tendon response to multiple cyclic tests including 3% constant peak strain level test (A-type test), 3% constant peak strain level test with two rest periods (B-type test), and 3∼4% different peak strain level test (C-type test). A sufficient number of specimens were tested at each type of the test to statistically evaluate many changes in response during testing and differences in response between each type of the test. In cyclic tests, there were decreses (relaxations) in the peak stresses and hysteresis, increases in the slack strains, and during lower peak strain level (3%) cyclic block after higher peak strain level (4%) cyclic block in the C-type tests. Considering the results of this study and those of the other study of multiple cyclic tests with rest periods by Hubbard and Chun, 1985, recovery phenomena during the rest periods occurred predominantly at the beginning of the rest periods. Consistently in both studies, the effects of rest periods were small and transient compared to the effects of the cyclic extensions. The recovery with cycles at lower peak strain level (3%) after higher peak strain level (4%) in the C-type test has not been previously documented. This recovery seems to be a natural phenomena in tissue behavior so that collagenous structures recover during periods of decreased demand.

  • PDF

Phospholipase A2 Contributes to Hemorrhage-induced Acute Lung Injury Through Neutrophilic Respiratory Burst (출혈성 쇼크에 의한 급성 폐손상에서 Phospholipase A2의 활성화에 의한 산화성스트레스의 역할)

  • Jang, Yoo-Suck;Kim, Seong-Eun;Jheon, Sang-Hoon;Shin, Tae-Rim;Lee, Young-Man
    • Tuberculosis and Respiratory Diseases
    • /
    • v.51 no.6
    • /
    • pp.503-516
    • /
    • 2001
  • Background : The present study was carried out in association with neutrophilic respiratory burst in the lung in order to clarify the pathogenesis of acute respiratory distress syndrome(ARDS) following acute severe hemorrhage. Because oxidative stress has been suggested as one of the principal factors causing tissue injury, the role of free radicals from neutrophils was assessed in acute hemorrhage-induced lung injury. Method : In Sprague-Dawley rats, hemorrhagic shock was induced by withdrawing blood(20 ml/kg of B.W) for 5 min and the hypotensive state was sustained for 60 min. To determine the mechanism and role of oxidative stress associated with phospholipase A2(PLA2) by neutrophils, the level of lung leakage, pulmonary myeloperoxidase(MPO), and the pulmonary PLA2 were measured. In addition, the production of free radicals was assessed in isolated neutrophils by cytochemical electron microscopy in the lung. Results : In hypotensive shock-induced acute lung injury, the pulmonary MPO, the level of lung leakage and the production of free radicals were higher. The inhibition of PLA2 with mepacrine decreased the pulmonary MPO, level of lung leakage and the production of free radicals from neutrophils. Conclusion : A. neutrophilic respiratory burst is responsible for the oxidative stress causing acute lung injury followed by acute, severe hemorrhage. PLA2 activation is the principal cause of this oxidative stress.

  • PDF