• 한국수산과학회지
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• 제33권6호
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• pp.520-523
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• 2000

Alginate를 가열에 의해 저분자화하여 저분자화에 따른 위점막 보호작용을 검토하기 위해 랫드에 있어서 저분자 alginate인 HAG-10, HAG-50, HAG-100 및 alginate의 투여 가 $HCl{\cdot}ethanol$ 용액과 침수스트레스에 의해 유발되는 위손상과 위궤양의 억제효과에 미치는 영향을 광학현미경으로 점막의 형태를 관찰하면서 그 억제율과 조직학적 변화를 측정하였다. $HCl{\cdot}ethanol$ 용액과 침수스트레스에 의해 유발되는 위손상과 위궤양에 대한 억제효과에 미치는 저분자 alginate의 영향을 검토한 결과, 그 억제효과는 alginate에서 가장 높았고, 다음으로 HAG-50과 HAG-100 및 HAG-10의 순으로 HAG-50, HAG-100 및 alginate에서 현저한 효과를 보였으나, HAG-10은 아무런 효과를 나타내지 않았다. 위손상과 위궤양점막을 광학현미경으로 관찰해 볼 때, 대조군과 HAG-10에서는 위점막 전체에 걸친 출혈과 부식에 의한 응고괴사가 진행되었고 점막 (粘膜)과 점막근판 (粘膜筋板) 및 근육층 (筋肉層)에 부종의 발생과 조직의 파괴가 일어났으나 HAG-50, HAG-100 및 alginate에서는 가벼운 병변이 진행되어 위점막층에 약간의 출혈만 관찰되어 위손상억제 및 위궤양 억제효과를 뚜렷히 나타내었다.

• 한국주거학회논문집
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• 제7권2호
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• pp.9-17
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• 1996

The Purpose of this study is to understand the relationship between residential environment and healthy behavior by examining the effect of environmental stress on psychology and physiology. With anxiety, the acute environmental stressor activates sympathy nerve system and the chonic environmental stressor activates the intenal secretion system because this stress induces depression. Thus, we could find that the continuity of these kinds of stresses brings the chronic disease.

• Natural Product Sciences
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• 제15권4호
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• pp.213-221
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• 2009

Longanae Arillus (the rind of fruits of Dimocarpus longan) has been consumed for the treatment of insomnia and anxiety in Asia. To provide further scientific basis to traditional uses of this fruit on insomnia, we evaluated the effects of methanol extract of Longanae Arillus (MELA) on the alteration of sleep architecture and electroencephalogram (EEG) power spectra in acutely and chronically restraint-stressed rats. Following postsurgical recovery, Polygraphic signs of sleep-wake activities were recorded for 24 h after MELA administration in rats. Rats in the acute stress and chronic stress were administered with MELA for 10 days. On the $8^{th},\;9^{th}\;and\;10^{th}$ day of MELA administration, the rats were stressed for 3 h once per day. On the $10^{th}$ day and 1 h after MELA administration, the rats were stressed once for 22 h in the chronic stress group. Acute and chronic stress induced alternations in cortex EEG recordings during non-rapid eye movement (NREM), rapid eye movement (REM) sleep and wakefulness. MELA shortened the total and REM sleep and increased the wakefulness in night time recording without changing daytime recordings. Chronic stress increased wakefulness and REM sleep, decreased total and NREM sleep in the daytime recording, and increased REM and decreased NREM sleep without changing total sleep and wakefulness in night time recording. These findings suggest that MELA ameliorated the alterations in REM and NREM sleep of acutely and chronically stressed rats via modulation of cortical ${\alpha}-$, ${\theta}-$ and ${\delta}-$ wave activity.

• Journal of Ginseng Research
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• 제34권1호
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• pp.30-40
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• 2010

The present investigation was conducted to evaluate the regulation of sleep architecture by the red ginseng water extract (RGE) in acutely and chronically restraint stressed rats. Adult rats were fitted with sleep.wake recording electrodes. Following post-surgical recovery, rats were extensively habituated for freely moving polygraphic recording conditions. Polygraphic signs of sleep-wake activities were recorded for 24 h after RGE administration and induction of stress and were analyzed to understand the regulation of sleep architecture. Acute stress decreased wakefulness and increased total sleep, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep in both the daytime and nighttime recording. RGE shortened the daytime NREM and REM sleep, without changing the wakefulness and total sleep. RGE increased nighttime wakefulness, and decreased total, NREM and REM sleep. Chronic stress increased wakefulness and decreased total sleep in the daytime recording, and increased REM and decreased NREM sleep in both the day and night time recording. RGE ameliorated chronic stress and induced alterations of REM and NREM sleep in the day and night time sleep architecture. Acute and chronic stress could also induce alternations in cortex electroencephalogram (EEG) recording during NREM, REM sleep and wakefulness. These findings suggest that RGE may modulate the sleep behavior in acutely and chronically stressed rats and the ameliorating effect of RGE on the sleep architecture may involve in modulation of $\alpha$-, $\theta$- and $\delta$- wave activities of the cortical EEG.

• 대한한의학방제학회지
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• 제11권2호
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• pp.135-146
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• 2003

Objectives : Wolguk-whan has been used as a prescription of natural drug for the treatment of stress digestive system disease. Recently, we reported that Wolguk-whan methnol extract (WGWM) exerted a significant protective effect against oxidative damage to the liver of ICR mice. This study was purposed to investigate the effects of Wolguk-whan water extract (WGWW) on liver injury induced by oxidative stress. Methods : In order to investigate the effects of WGWW on acute liver injury, ICR mice were pretreated with WGWW for 6days, starved for 24hrs, and administerated acetamirtophen(500mg/kg, i.p.). In the liver homogenates, lipid peroxide and glutathione(GSH) levels were measured. In addition, activities of hepatic enzyme, such as catalase, glutathione peroxidase(GSH-Px), glutathione S-transferase(GST) were measured in the hepatic mitochondrial and cytosolic fractions. Results : In vivo administeration of WGWW showed effective inhibition of acetaminophen induced lipid peroxidation, and showed elevations of GSH level, catalase, GSH-Px, GST activities. Conclusions : These results suggested that WGWW might suppress the formation of oxidative metabolites, and prevent acetaminophen induced hepatotoxicity.

• Structural Engineering and Mechanics
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• 제60권1호
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• pp.1-19
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• 2016

In this study, the supersonic panel flutter of doubly curved composite sandwich panels with variable thickness is considered under aerothermoelastic loading. Considering different radii of curvatures of the face sheets in this paper, the thickness of the core is a function of plane coordinates (x,y), which is unique. For the first time in the current model, the continuity conditions of the transverse shear stress, transverse normal stress and transverse normal stress gradient at the layer interfaces, as well as the conditions of zero transverse shear stresses on the upper and lower surfaces of the sandwich panel are satisfied. The formulation is based on an enhanced higher order sandwich panel theory and the vertical displacement component of the face sheets is assumed as a quadratic one, while a cubic pattern is used for the in-plane displacement components of the face sheets and the all displacement components of the core. The formulation is based on the von $K{\acute{a}}rm{\acute{a}}n$ nonlinear approximation, the one-dimensional Fourier equation of the heat conduction along the thickness direction, and the first-order piston theory. The equations of motion and boundary conditions are derived using the Hamilton principle and the results are validated by the latest results published in the literature.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.343-349
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• 2010

The effects of osmotic stress on the non-specific immune response of Nile tilapia, Oreochromis niloticus, were investigated. Osmoregulatory mechanism of tilapia has been studied, but less information is available about innate immune response of O. niloticus faced with hyperosmolality. Acute osmotic stress was elicited by transferring tilapia from freshwater (FW) to 24 psu seawater (SW). Non-specific immune parameters including lysozyme activities of plasma and head kidney (HK), alternative complement pathway (ACP) activity in plasma, phagocytic capacities of spleen and HK immune cells, and respiratory burst activity of immune cells in both HK and spleen were analyzed. Lysozyme activities were increased at 1 h and 30 h after transfer to SW, but decreased at 10 h after SW transfer. Conversely, ACP activity increased 10 h after SW transfer. Phagocytic capacity increased slightly at 1 h and 5 h after SW transfer, and respiratory burst activity showed an increase in superoxide release at 10 h after SW transfer. Taken together, these results indicate that the exposure of tilapia to hyperosmotic conditions has immunostimulatory effects on cellular and humoral immune reactions.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.104-108
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• 1995

Von Mises stress and compliance distribution was evaluated using a finite element analysis on the anastomosis of an artery with length of 20mm, inner diameter of 4mm, thickness of 0.5mm and a PTFE graft with length of 5.7mm, Inner diameter of 2mm. thickness of 0.2mm. When anastomotic angle was taken as $45^{\circ}$ and inner pressure of $1330\;dyne/mm^2$ was applied inside the 2 conduits. From the analysis results were obtained as follows. (1)Artery diameter increased in both horizontal x and vertical y directions and the magnitude of that in x direction was bigger than in y direction. (2) The compliance was maximum on the anastomosis. especially on that with acute angle. This reduced approaching to the right or left end. (3) The equivalent stress was maximum on top in the y direction and winimum on the nodes around $110^{\circ}$ in circumferential direction from the top. (4) The equivalent stress was maximum in the vicinity of anastomosis with acute angle along the longitudinal direction of the artery. This trend was also observed along the PTFE graft.

• 동의생리병리학회지
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• 제27권5호
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• pp.644-649
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• 2013

In this study, we aimed to investigate the effect of GamiChungYi-tang(GCY-t) on caerulein-induced acute pancreatitis (AP). It is performed by detecting oxidative stress markers and observing histopathological examination. Thirty adult male rats(Sprague-Dawley) were divided into six groups as follows: normal (NOR,n=5), caerulein-induced (CON,n=5), caerulein+Cefotaxime Sodium(CT,n=5), caerulein+GCY-t (130 mg/kg, CHA,n=5), caerulein+GCY-t (260 mg/kg, CHB,n=5) and caerulein+GCY-t (520 mg/kg, CHC,n=5) groups. Pancreatic tissues of rats from all groups were removed for apoptosis and light, and electron microscopic examination. Blood of rats from all groups were collected for oxidative stress markers inspection and pathological examination. Pancreatic oxidative stress markers were evaluated by the measurements of leukocyte, serum amylase and platelet activating factor (PAF), Interleukin-6 (IL-6) levels were determined spectrophotometrically. CON group has a significant increase (p<0.05) in amylase compared with NOR, but CT and CHA, CHB, CHC groups reduced the levels of these enzyme. The levels of Platelet activating factor (PAF) were increased in CON compared with NOR, but decreased in CT and CHA, CHB, CHC groups compared with CON. Interleukin-6 (IL-6) levels were increased significantly in CON compared with NOR, but reduced in CT and CHA, CHB, CHC groups. In the observations of Optical microscopy and electron microscopy, The experimental groups showed the significant decreases in pancreatic tissue inflammation, edema, vacuolization, necrosis compared to the control group. After all, GCY-t is potentially capable of limiting pancreatic damage produced during AP by restoring the fine structure of acinar cells and tissue.

• 대한한방내과학회지
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• 제34권3호
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• pp.298-311
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• 2013

Objectives : In this study, we aimed to investigate the effect of Eunhoebanchong-san (EBS) on caerulein-induced acute pancreatitis (AP) by detecting oxidative stress markers and performing histopathological examination. Methods : Thirty adult male Sprague-Dawley rats were divided into five groups as follows: normal (NOR), caerulein-induced (CON), caerulein+EBS (130 mg/kg, EA), caerulein+EBS (260 mg/kg, EB) and caerulein+EBS (520 mg/kg, EC) groups. Pancreatic tissues of rats from all groups were removed for apoptosis, and light, and electron microscopic examination. Blood of rats from all groups was obtained for oxidative stress markers and pathological examination. Pancreatic oxidative stress markers were evaluated by the measurements of serum amylase, and interleukin-6 (IL-6) levels were determined spectrophotometrically. Results : The ratio of pancreas/body weight increased significantly in the CON compared with the NOR, but decreased significantly in the EA, the EB, the EC groups compared with the CON. Caerulein administration resulted in a significant increase in amylase, but EBS reduced the levels of these enzymes. Interleukin-6 (IL-6) levels increased significantly in CON compared with NOR, but reduced in EA, EB, and EC group at 24 hrs. In the observations of optical microscopy and electron microscopy, the experimental groups showed significant decreases in pancreatic tissue inflammation, edema, vacuolization, necrosis compared to the control group. Altogether, this indicates EBS is potentially capable of limiting pancreatic damage produced during AP by restoring the fine structure of acinar cells and tissue. Conclusions : We concluded that EBS may have beneficial effects in the treatment of caerulein-induced AP.