• Title/Summary/Keyword: WATER STRESS

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Analysis on dynamic numerical model of subsea railway tunnel considering various ground and seismic conditions (다양한 지반 및 지진하중 조건을 고려한 해저철도 터널의 동적 수치모델 분석)

  • Changwon Kwak;Jeongjun Park;Mintaek Yoo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.6
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    • pp.583-603
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    • 2023
  • Recently, the advancement of mechanical tunnel boring machine (TBM) technology and the characteristics of subsea railway tunnels subjected to hydrostatic pressure have led to the widespread application of shield TBM methods in the design and construction of subsea railway tunnels. Subsea railway tunnels are exposed in a constant pore water pressure and are influenced by the amplification of seismic waves during earthquake. In particular, seismic loads acting on subsea railway tunnels under various ground conditions such as soft ground, soft soil-rock composite ground, and fractured zones can cause significant changes in tunnel displacement and stress, thereby affecting tunnel safety. Additionally, the dynamic response of the ground and tunnel varies based on seismic load parameters such as frequency characteristics, seismic waveform, and peak acceleration, adding complexity to the behavior of the ground-tunnel structure system. In this study, a finite difference method is employed to model the entire ground-tunnel structure system, considering hydrostatic pressure, for the investigation of dynamic behavior of subsea railway tunnel during earthquake. Since the key factors influencing the dynamic behavior during seismic events are ground conditions and seismic waves, six analysis cases are established based on virtual ground conditions: Case-1 with weathered soil, Case-2 with hard rock, Case-3 with a composite ground of soil and hard rock in the tunnel longitudinal direction, Case-4 with the tunnel passing through a narrow fault zone, Case-5 with a composite ground of soft soil and hard rock in the tunnel longitudinal direction, and Case-6 with the tunnel passing through a wide fractured zone. As a result, horizontal displacements due to earthquakes tend to increase with an increase in ground stiffness, however, the displacements tend to be restrained due to the confining effects of the ground and the rigid shield segments. On the contrary, peak compressive stress of segment significantly increases with weaker ground stiffness and the effects of displacement restrain contribute the increase of peak compressive stress of segment.

Effect of Long Term Waterlogging on the Growth and Nutrient Contents of 'Campbell Early' and 'Kyoho' Grapevine Cultivars (장기 침수가 포도 '캠벨얼리'와 '거봉' 품종의 생육과 양분함량에 미치는 영향)

  • Kang, Seok-Beom;Lee, In-Bog;Jang, Han-Ik;Park, Jin-Myeon;Moon, Doo-Khil
    • Korean Journal of Environmental Agriculture
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    • v.27 no.2
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    • pp.178-184
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    • 2008
  • This work was carried out to investigate the effect of waterlogging on the growth and nutrient contents of 'Campbell Early' and 'Kyoho' grapevines under the vinyl house condition from June 14 to July 20, 2005. For the trial, seedlings of two-year-old grapevine were transplanted to 40 L pot with a sandy loam soil. Irrigation point of non-waterlogging(control) treatment was controlled at -40 kPa of soil water tension using tensiometer and waterlogging treatments were imposed for 35 days at the water levels of above 10 cm from the soil surface using tap water. The growth of aerial(shoot length, leaf number and stem diameter) and underground(root) parts of 'Campbell Early' and 'Kyoho' grapevines tended to be wholly reduced by waterlogging, while the growth of aerial parts were more severely impaired in 'Kyoho' than in 'Campbell Early' cultivar. The different responses for waterlogging between two grapevines seem to be related with the capacity for absorbing mineral nutrients, because nitrogen content of 'Campbell Early' cultivar leaves was significantly higher than that of 'Kyoho' cultivar although the contents of phosphorus and potassium in leaves of two grapevine cultivars were similarly declined. There was no significant different of fruit quality, such as contents of soluble solid, titratable acidity and weight of berry in 'Campbell Early' between waterlogging and control. In 'Kyoho' cultivar, however, berry weight and titratable acidity were decreased and soluble solid content was increased by waterlogging. It was assumed that waterlogging stress for grapevines promotes maturation and coloring processes of berries by stimulating maturation hormone such as ethylene. In conclusion, 'Campbell Early' cultivar seems to be more tolerable than 'Kyoho' cultivar when comparing the growth responses and nutrient contents between two grapevine cultivars under waterlogging.

Risk Factors of Primary Nocturnal Enuresis (일차성 야뇨증의 위험 요인)

  • Lee, Soo-Jin;Yang, Jung-An;Yoo, Eun-Sun;Seo, Jang-Wan;Lee, Seung-Joo
    • Childhood Kidney Diseases
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    • v.4 no.1
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    • pp.69-76
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    • 2000
  • Purpose: The Pathogenesis of primary noctllrnal enuresis(PNE) is still controversial. Genetic factor and maturational delay of micturition reflex including arousal disorder, lack of nocturnal Arginine Vasopressin(AVP) release and functional bladder capacity have been suggested. We analyzed the risk factors of PNE. Methods: Fifty five children with PNE (20 enuretics diagnosed at school physical examination of the first grade students at Mok-Dong Elementary School and 35 enuretics (Age 6-7 year) diagnosed at Ewha Womans University Mok Dong Hospital) and 221 control students without PNE at school physical examination were included. Genetic, stress and developmental factors, arousability, water intake, urine volume, maximun voiding volume and daytime voiding dysfunction were compared. Results: 1) There was no significant difference between PNE and control group in sex ratio, birth order, percentage of working mothers, parental and child personality, age to start walking, school record and duration of sleep. 2) Family history in the PNE group was significantly higher than control group ($20.0\%\;vs\;2.7\%$)(P<0.05). 3) The difficulty in arousal in the PNE group was significantly more common than the control group ($70.9\%\;vs\;54.3\%$)(P<0.05). 4) Nocturnal water intake in the PNE group was significantly greater than the control group ($330{\pm}158.2\;mL\;vs\;235{\pm}129.5\;mL$). Nocturnal urine volume in the PNE group was significantly greater than the control group ( $390{\pm}61.5\;mL\;vs\;140{\pm}43.2\;mL$)(P<0.05). Daily water intake and daily urine volume did not significantly differ between the two groups. 5) Maximum urine volume per void in the PNE group was significantly lower than the control group ($107{\pm}35.9\;mL\;vs\;236{\pm}41.3\;mL$). Daytime voiding dysfunction in the PNE group was significantly more common than the control group ($80.0\%\;vs\;57.9\%$). The voiding frequency in the PNE group was significantly greater than the control group ($7.0{\pm}3.6\;vs\;5.4{\pm}1.6$)(P<0.05). Conclusion: In addition to genetic factors and maturational delay of micturition reflex (difficulty in arousal, nocturnal polyuria and decreased functional bladder capacity) nocturnal polydypsia was found to be the important risk factors fur PNE. So nocturnal fluid restriction should be encouraged as the first-line management of PNE.

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Responses of Root Growth Characters to Waterlogging in Soybean [Glycine max (L.) Merrill] (과습에 따른 콩 지하부 생육반응)

  • Lee, Jae-Eun;Kim, Hong-Sig;Kwon, Young-Up;Jung, Gun-Ho;Lee, Chun-Ki;Yun, Hong-Tai;Kim, Chung-Kon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.1
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    • pp.1-7
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    • 2010
  • Stress from excess water is one of the most harmful limiting factor in soybean yield during the wet season under the climate conditions. Soybean is very sensitive to excess water compare to other crops. This experiment was carried out to identify the growth responses for establishing a screening system related to waterlogging tolerance in soybean from 2003 to 2004. The root dry weight accumulation rate of per day for 21 days after waterlogging at V5 stage was the highest in Pungsannamulkong (47~56% of control) and was the lowest in Jangyeobkong (26~27% of control). The nodules dry weight recovery rate was the highest in Pungsannamulkong (83~91% of control), while the lowest in Myungjunamulkong (48~66% of control). After waterlogging, recovery rate of roots was high, which increased the root/shoot ratio of Pungsannamulkong, which also produced significantly more adventitious roots than in Jangyeobkong. The percentage of adventitious roots fresh weight to the total roots fresh weight was the lowest in Myungjunamulkong (14%), while the highest in Pungsannamulkong (38%). This results implies that the water and nutrients absorbing ability of Pungsannamulkong is more higher than that of Myungjunamulkong during late growth period.

Xylem Sap Flow Affected by Short-term Variation of Soil Moisture Regimes at Higher Growth Period in 'Fuji'/M.9 Apple Trees with Different Fruit Loads (착과량 수준 및 생육성기 토양수분 함량 변화에 따른 '후지'/M.9 품종의 수액이동 특성)

  • Park, Jeong-Gwan;Kim, Seung-Heui;Lee, In-Bok;Park, Jin-Myeon
    • Korean Journal of Environmental Agriculture
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    • v.25 no.2
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    • pp.164-169
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    • 2006
  • This study was conducted for 10 days from 17 July to 26 July in 2005 to measure the amount of xylem sap flow under short-term variation of soil moisture regimes at -20 kPa, -50 kPa and -80 kPa in eight-year-old 'Fuji'/M.9 apple trees with different fruit loads. Fruit load was adjusted as three different treatments with standard (100%), 1/2 times (50%) and 2 times (200%) on the basis of optimum fruiting number per tree as the standard fruit load of Fuji cultivar. Trees with standard fruit load during the experimental period showed higher xylem sap flow at -50 kPa of soil moisture regimes than those of trees with 1/2 times and 2 times fruit load. Trees with 1/2 times and 2 times fruit load had similar patterns of the diurnal changes of xylem sap flow, vapor pressure deficit (VPD), and maximum evapotranspiration (ETm). However, trees with 2 times fruit load at -50 kPa and -80 kPa of soil moisture regimes produced lower amount of xylem sap flow than ETm. Trees with standard fruit load produced $1.06{\sim}3.93$ L/tree more amount of xylem sap flow than ETm at all soil moisture regimes. But xylem sap flow of tees with 2 times fruit load had 21% lower at -50 kPa and $31{\sim}36%$ lower at -20 kPa and -80 kPa of soil moisture regimes, respectively than that of trees with standard fruit load. Shoot growth and leaf area were significantly the highest in trees with standard fruit load while those of trees with 2 times fruit load recorded significantly lowest. Leaf water potential of trees with standard fruit load was lower than that of trees with 1/2 times and 2 times fruit load. It indicated that tees with standard fruit load had higher water use for transpiration than other treatments and tees with 2 times fruit load received more stress for the transpiration process under low soil moisture regimes. Consequently, 'Fuji'/M.9 apple trees, the fruit load and soil moisture should be maintained optimum to increase xylem sap flow and transpiration during higher growth period.

Structural Analysis of PWR(pressurized water reactor) Canister for Applied Impact Force Occurring at the Moment of Falling Plumb Down Collision (추락낙하 충돌 시 가해지는 충격에 대한 경수로(PWR) 처분용기의 구조해석)

  • Kwon, Young-Joo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.2
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    • pp.211-222
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    • 2011
  • In this paper a structural analysis of the PWR(pressurized water reactor) canister with 102cm diameter is carried out to evaluate the structural safety of the canister for the impact force occurring at the moment of collision with the ground in the falling plumb down accident from the carriage vehicle which may happen during the canister handling at the spent nuclear fuel disposal repository. For this, a rigid body dynamic analysis of the canister is executed to compute the impact force using the commercial CAE system, RecurDyn, and a nonlinear structural analysis is performed to compute stresses and deformations occurring inside the canister for this computed impact force using the commercial FEM code, NISA. From these analysis results, the structural safety of the canister is evaluated for the falling plumb down accident from the carriage vehicle due to the inattention during the canister handling at the repository. The rigid body dynamic analysis performed assuming the canister as a rigid body shows that the canister falls plumb down to the ground in two types. And also it shows that early collision impact force is the biggest one and following impact forces decrease gradually. The height of the carriage vehicle in the repository is assumed as 5m in order to obtain the stable structural safety evaluation result. The nonlinear structural analysis of the canister is executed for the biggest early impact force. The structural analysis result of the canister shows that the structural safety of the PWR canister is not secured for the falling plumb down accident from the moving carriage vehicle because the maximum stresses occurring in the cast iron insert of canister are bigger than the yield stress of the cast iron.

Effects of Minerals Added to Medicinal Plant Extracts on Alcohol-Induced Oxidative Stress and Alcohol Metabolism in Rats (약용식물 추출물이 첨가된 미네랄이 알코올에 의한 산화적 스트레스 및 숙취해소에 미치는 효과)

  • Lee, Seok-Jun;Kim, Andre;Lee, Jae-Hwa;Kim, Mee-Hee;Lee, Bong-Sang;Jee, Young-Taek;Bin, Jae-Hun;Ha, Jong-Myung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.393-400
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    • 2011
  • This study investigates the effects of a hangover beverage (MIX) that contains minerals (highly-salty mineral water, HSMW) and several medicinal plant extracts, on antioxidant and alcohol-metabolizing enzymes in alcohol administered Sprague-Dawley rats. HSMW is pumped from below the sedimentary rock layer of Dadaepo, Busan, South Korea, which is 1,050 m below the land surface; it tastes salty, like sea water. In terms of medicinal plant extracts, the total phenolic and flavonoid contents of Rubus coreanus and Cornus officinalis were measured as being significantly higher than those in Curcuma longa. The results suggest that treatment with MIX significantly increases superoxide dismutase (SOD) activity and DPPH radical scavenging activity. In the 10% HSMW-, for MIX- and company product (CP)-treated groups, the concentration of blood alcohol was significantly reduced 1~5 hr after alcohol loading, compared to that in the control group. In hepatic alcohol-metabolizing enzyme activities, alcohol dehydrogenase (ADH) activity was found to be higher in the MIX- and CP-treated groups than in controls, whereas acetaldehyde dehydrogenase (ALDH) activity was significantly higher in the CP-treated groups than other groups. This study concludes, therefore, that MIX (HSMW) minerals, like as Zn, Ca, Mg, Mn, and others stimulate alcohol-metabolizing enzymes, while the antioxidants of plant extracts prevent the damage otherwise incurred by alcohol toxicity. These results suggest that the hangover beverage (MIX) alleviates alcohol hangover symptoms by stimulating activities related to hepatic alcohol-metabolizing enzymes and antioxidant effects.

A Study on Antiulcer Effects of Opuntia dillenii Haw. on Stomach Ulcer Induced by Water-immersion Stress in Rats (랫드의 스트레스성 위궤양에 대한 Opuntia dillenii Haw.(선인장)의 항궤양작용에 관한 연구)

  • 이후장;이용욱;김정현
    • Journal of Food Hygiene and Safety
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    • v.13 no.1
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    • pp.53-61
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    • 1998
  • This study was performed to investigate the antiulcer effects of Opuntia dillenii Haw. on the stomach ulcer induced by restraint and water-immersion stress in rats. For this experiment, 48 male Sprague-Dawley strain were used. The experimental groups were divided into four: a control (C) and 3 Opuntia dillenii Haw. treatment groups (E-1, E-2, E-3). Each dose of Opuntia dillenii Haw. was 30 mg/kg bw (E-1), 60 mgfKg bw (E-2) and 120 mg/kg bw (E-3). The rats were allocated to each group by 12 and observed for 4 weeks. The results were as following: 1. The stomach surface pH in each group showed no significant difference, but the values of Opuntia dillenii Haw. treatment groups were higher than the value of the control group. 2. The gastric wall mucus was increased in all Opuntia dillenii Haw. treatment groups compared with the control group. Especially in E-1 difference was higher (p<0.05) and in E-2 difference was significantly higher (p<0.01). 3. At shear rate 11.25, 45.0, 90.0, $225\;sec^{-1}$, whole blood viscosity and plasma viscosity were measured. Most of the values of Opuntia dillenii Haw. treatment groups were low compared with that of the control group. At shear rate 90.0, $225\;sec^{-1}$ the values of whole blood viscosity in E-1 were significantly low (p<0.05) and at shear rate 11.25, $45.0\;sec^{-1}$, more significant (p<0.01). At shear rate 11.25, 45.0, 90.0, $225\;sec^{-1}$ the values of whole blood viscosity in E-2 were significantly low (p<0.01). At shear rate $90.0\;sec^{-1}$ the value of plasma viscosity in E-1 was significantly low (p<0.05) and at shear rate 90.0, $225\;sec^{-1}$ the values of plasma viscosity in E-2 we resignificantly low (p<0.01). 4. Less severe ulcers were obsered in Opuntia dillenii Haw. treatment groups than in the control group. Especially E-1 groups tissues had only slight ulcers and necrosis of tissue was not observed in this group. From the results of this study, it can be concluded that the oral administratio-n of Opuntia dillenii Haw. results in protection of stomach ulcer by stimulating the secretion of gastric mucus and improving the gastric mucosal microcirculation.

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One-stop Evaluation Protocol of Ischemic Heart Disease: Myocardial Fusion PET Study (허혈성 심장 질환의 One-stop Evaluation Protocol: Myocardial Fusion PET Study)

  • Kim, Kyong-Mok;Lee, Byung-Wook;Lee, Dong-Wook;Kim, Jeong-Su;Jang, Yeong-Do;Bang, Chan-Seok;Baek, Jong-Hun;Lee, In-Su
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.33-37
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    • 2010
  • Purpose: In the early stage of using PET/CT, it was used to damper revision but recently shows that CT with MDCT is commonly used and works well for an anatomical diagnosis. This hospital makes the accuracy and convenience more higher in the diagnosis and evaluate of coronary heart disease through concurrently running myocardial perfusion SPECT examination, myocardial PET examination with FDG, and CT coronary artery CT angiography(coronary CTA) used PET/CT with 64-slice. This report shows protocol and image based on results from about 400 coronary heart disease examinations since having 64 channels PET/CT in July 2007. Materials and Methods: An Equipment for this examination is 64-slice CT and Discovery VCT (DVCT) that is consisted of PET with BGO ($Bi_4Ge_3O_{12}$) scintillation crystal by GE health care. First myocardial perfusion SPECT with pharmacologic stress test to reduce waiting time of a patient and get a quick diagnosis and evaluation, and right after it, myocardial FDG PET examination and coronary CTA run without a break. One-stop evaluation protocol of ischemic heart disease is as follows. 1)Myocardial perfusion SPECT with pharmacologic stress: A patient is injected with $^{99m}Tc$-MIBI 10 mCi and does not have any fatty food for myocardial PET examination and drink natural water with ursodeoxcholic acid 100 mg and we get SPECT image in an hour. 2)Myocardial FDG PET: To reduce blood fatty content and to increase uptake of FDG, we used creative oral glucose load using insulin and Acipimox to according to blood acid content. A patient is injected with $^{18}F$-FDG 5 mCi for reduction of his radiation exposure and we get a gated image an hour later and get delay image when we need. 3) Coronary CTA: The most important point is to control heart rate and to get cooperation of patient's breath. In order to reduce a heart rate of him or her below 65 beats, let him or her take beta blocker 50 mg ~ 200 mg after a consultation with a doctor about it and have breath-practices then have the examination. Right before the examination, we spray isosorbide dinitrate 3 to 5 times to lower tension of bessel wall and to extension a blood wall of a patient. It makes to get better the shape of an anatomy. At filming, a patient is injected CT contrast with high pressure and have enough practices before the examination in order to have no problem. For reduction of his radiation exposure, we have to do ECG-triggered X-ray tube modulation exposure. Results: We evaluate coronary artery stenosis through coronary CTA and study correlation (culprit vessel check) of a decline between stenosis and perfusion from the myocardial perfusion SPECT with pharmacologic stress, coronary CTA, and can check viability of infarction or hibernating myocardium by FDG PET. Conclusion: The examination makes us to set up a direction of remedy (drug treatment, PCI, CABG) because we can estimate of effect from remedy, lesion site and severity. In addition, we have an advantage that it takes just 3 hours and one-stop in that all of process of examinations run in succession and at the same time. Therefore it shows that the method is useful in one stop evaluation of ischemic heart disease.

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The Protective Effects of Ethanol Extract of Wild Simulated Ginseng on Carbon Tetrachloride Induced Acute Hepatic Injury in Mouse (사염화탄소 유발 급성 간독성 생쥐모델에서 산양삼 에탄올 추출물의 간 보호 효과)

  • Lee, Soo-Min;Park, Sun-Young;Jang, Gi-Seuk;Ly, Sun-Yung
    • Journal of Nutrition and Health
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    • v.41 no.8
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    • pp.701-710
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    • 2008
  • The wild simulated ginseng (WSG) has been effectively used in folk medicine as a remedy against hepatic disease, hypertension and arthritic disease. However, there is still lack of scientific proof about its antioxidant capability. The present study has been conducted to evaluate the protective role of the WSG ethanol extract in the CCl4-induced oxidative stress and resultant hepatic disfunction in ICR mice. The electron donating abilities and IC50 of WSG etnanol extract were 76.86 ${\pm}$ 1.06% and 33.3 ${\mu}g$/mL (that of ascobic acid was 16.5 ${\mu}g$/mL), respectively. Total antioxidant status of WSG extract was 2.13 ${\pm}$ 0.06 mmoL/mg, while the values of ascorbic acid and BHT were 3.63 ${\pm}$ 0.06 and 3.12 ${\pm}$ 0.02, respectively. ICR mice (aged 3weeks) were fed for 4 weeks on AIN-93M diet and had free access to food and water. The animals were divided into three groups: normal group (intraperitoneally (i.p) injected with PBS at 100 ${\mu}L$/mouse), group C; CCl4-induced and without any treatment. (i.p injected only PBS, 100 ${\mu}L$ /mice), group G; CCl4-induced and treated with WSG (i.p injected with 5 mg WSG extract per mouse, suspended in 100 ${\mu}L$ phosphate buffer). After the i.p. injection of WSG or PBS (5 times for 7weeks), all mice were administered CCl4 in olive oil at the last day of the experiment, except for normal group. The normal group was administered only olive oil. Determination of plasma triglyceride, total cholersterol, fasting glucose and GPT activity was performed using automatic blood analyzer. To evaluate the protective effect against the oxidative stress, DNA fragmentation and TBARS were determined in blood leucocytes and RBC and hepatocyte, respectively. Body and organs weights and food intake did not show significant differences among the groups. Blood total cholesterol of group G was similar to that of normal group, which was the lowest in group C. The fasting blood glucose level was the highest in normal group (205.20 ${\pm}$ 135.24), which were decreased in group C (134.2 ${\pm}$ 79.31) and group G (126.48 ${\pm}$ 77.05). TBARS values in a red blood cell and hepatic tisuue homogenate were lower in group G comparing to the group C. DNA% in tail, tail length (TL) and tail moment (TM) of blood leucoocytes showed the highest values in group C (20.11 ${\pm}$ 2.47, 17.36 ${\pm}$ 2.58, 94.11 ${\pm}$ 12.29) and they were significantly diminished in group G (9.63 ${\pm}$ 1.19, 7.04 ${\pm}$ 1.50, 38.64 ${\pm}$ 7.60). In conclusion, wild simulated ginseng might be a protective agent against the oxidative stress.