• Geomechanics and Engineering
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• v.33 no.2
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• pp.167-174
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• 2023

This study evaluated slope stability through a case study to determine the disaster risks associated with increased deforestation in structures, including schools and apartments, located in urban areas adjacent to slopes. The slope behind the ○○ High School in Gwangju, Korea, collapsed owing to heavy rain in August 2018. Historically, rainwater drained well around the slope during the rainy season. However, during the collapse, a large amount of seepage water flowed out of the slope surface and a shallow failure occurred along the saturated soil layer. To analyze the cause of the collapse, the images of the upper area of the slope, which could not be directly identified, were captured using unmanned aerial vehicles (UAVs). A digital elevation model of the slope was constructed through image analysis, making it possible to calculate the rainfall flow direction and the area, width, and length of logging areas. The change in the instability of the slope over time owing to rainfall lasting ten days before the collapse was analyzed through numerical analysis. Imaging techniques based on the UAV images were found to be effective in analyzing ground disaster risk maps in urban areas. Furthermore, the analysis was found to predict the failure before its actual occurrence.

• Structural Engineering and Mechanics
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• v.86 no.6
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• pp.751-764
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• 2023

In practical engineering such as aerial refueling pipes, the boundary of the fluid-conveying pipe is difficult to be completely immovable. Pipes under movable and immovable boundaries are controlled by different dominant nonlinear factors, where the boundary mobility will affect the nonlinear dynamic characteristics, which should be focused on for adopting different strategies for vibration suppression and control. The nonlinear dynamic instability characteristics of functionally graded fluid-conveying pipes lying on a viscoelastic foundation under movable and immovable boundary conditions are systematically studied for the first time. Nonlinear factors involving nonlinear inertia and nonlinear curvature for pipes with a movable boundary as well as tensile hardening and nonlinear curvature for pipes with an immovable boundary are comprehensively considered during the derivation of the governing equations of the principal parametric resonance. The stability boundary and amplitude-frequency bifurcation diagrams are obtained by employing the two-step perturbation- incremental harmonic balance method (TSP-IHBM). Results show that the movability of the boundary of the pipe has a great influence on the vibration amplitude, bifurcation topology, and the physical meanings of the stability boundary due to different dominant nonlinear factors. This research has guidance significance for nonlinear dynamic design of fluid-conveying pipe with avoiding in the instability regions.

• Journal of Society of Preventive Korean Medicine
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• v.27 no.3
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• pp.35-46
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• 2023

Objectives : Gumiganghwal-tang and its main components have been used for treatment of cough, headache, joint pain and fever. Using a respiratory inflammatory model, we intend to demonstrate the its anti-inflammatory effect and immune mechanism of Gumiganghwal-tang. Methods : We induced the respiratory inflammation mouse model by papain treatment. Female BALB/C mice (8 weeks old) were divided into three groups as follows: saline control group, papain treatment group (vehicle), papain and Gumiganghwal-tang (200 mg/kg) treatment group (n=4). To verify the anti-inflammatory effect of Gumiganghwal-tang extracts, we measured the infiltration of inflammatory cells in bronchoalveolar lavage fluid (BALF) and nasal lavage fluid (NALF). Additionally, the efficacy of Gumiganghwal-tang extracts on Th2 cell population and alveolar macrophage in lung were analyzed by using flow cytometry. Results : Gumiganghwal-tang extracts administration decreased inflammatory cell infiltration in BALF and NALF, especially of eosinophils. Furthermore, interleukin-5 level was reduced in lung by drug administration. Interestingly, Gumiganghwal-tang extracts treatment also decreased the Th2 cell (CD4⁺GATA3⁺) population and increased the alveolar macrophage (CD11b⁺CD11c⁺) population in lung. Conclusions : Our findings indicate that Gumiganghwal-tang extracts have anti-inflammatory effects by mediating Th2 cell and alveolar macrophage cell activation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.732-737
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• 2012

The aim of this study is examine the protection effect for artery and antithrombotic effect of Sokmyong-tang(SMT; xuming-tang) on carotid artery thrombosis in a rat model. Thirty minutes before $FeCl_3$ treatment, SD rats were intraperitoneal injected with SMT. We tested the effects of SMT on time to occlusion (TTO) in thrombosis model by induced $FeCl_3$ using the laser Doppler flow meter and accessed thrombus weight (TW) inhibition and measured collagen fibers in the vessel after injury using Masson's trichrome stain. SMT(100 mg/kg, i.p.) showed significantly delayed TTO ($13.17{\pm}1.33$ min, P < 0.001) compared to vehicle control group ($8.63{\pm}0.92$ min) and inhibiting effect on TW with $0.72{\pm}0.02$ mg/mm (P < 0.05). In addition, SMT prevented collagen fibres damage in injured vessel ($22.24{\pm}4.48%$, P < 0.001). These results provide experimental evidence for SMT can be used to prevent vascular injury and thrombosis such as hypertension, arteriosclerosis, and so on.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.257-263
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• 2009

This study aimed to investigate whether selective serotonin reuptake inhibitors (SSRIs) attenuate brain injury and facilitate recovery following photothrombotic cortical ischemia in mice. Male ICR mice were anesthetized and systemically administered Rose Bengal. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold light laser. The animals were treated with fluoxetine or sertraline once a day for 14 d starting 1 h after ischemic insult. Treatment with fluoxetine and sertraline significantly reduced the infarct size. The Evans blue extravasation indices of the fluoxetine- and sertraline-treated groups were significantly lower than that of the vehicle group. Treatment with fluoxetine and sertraline shifted the lower limit of the mean arterial blood pressure for cerebral blood flow autoregulation toward normal, and significantly increased the expression of heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1 ${\alpha}$ (HIF-1 ${\alpha}$) proteins in the ischemic region. These results suggest that SSRIs, such as fluoxetine and sertraline, facilitate recovery following photothrombotic cortical ischemia via enhancement of HO-1 and HIF-1 ${\alpha}$ proteins expression, thereby providing a benefit in therapy of cerebral ischemia.

• Biomedical Science Letters
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• v.11 no.3
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• pp.355-363
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• 2005

This study aimed to investigate the cerebroprotective effect of vascular endothelial growth factor (VEGF) on permanent focal cerebral ischemia in Sprague-Dawley rats. Right middle cerebral artery (MCA) was occluded for 6 and 24 hours by an intraluminal monofilament technique. An open cranial window was made on the right parietal bone for determination of continuous changes in regional cerebral blood flow (rCBF) by laser-Doppler flowmetry. The infarct size was morphometrically determined using the 2,3,5-triphenyltetrazolium chloride technique. Brain edema was determined by measuring brain water content. In normal rats, rCBF was significantly increased by intravenous infusion of VEGF for 10 minutes. The VEGF-induced increase in rCBF was significantly inhibited by pretreatment with suramin, a heparin-binding growth factor inhibitor as well as $N^{\omega}-nitro-L-arginine$, a nitric oxide synthase inhibitor. In focal cerebral ischemic rats, the amplitude of decrease in rCBF during ischemic period was significantly less in VEGF-treated group, compared with that in vehicle-treated group. The cerebral infarct size was reduced by VEGF in a dose-dependent manner. The brain edema formation was dose-dependently reduced by VEGF in 24-hour MCA occlusion group but not in 6-hour MCA occlusion group. It is suggested that VEGF not only improves the rCBF during cerebral ischemic period but also reduces the brain edema formation, and thereby exert a protective effect on focal cerebral ischemia in rats.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.301-310
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• 2013

Jet fans are installed in road tunnels in order to maintain critical velocity when fire occurs. Generally the number of jet fans against fire are calculated by considering critical velocity and flow resistance by wall friction, vehicle drag force, thermal buoyance force and natural wind. In domestic case, thermal buoyance force is not considered in estimating the number of jet fans. So, in this study, we investigated the pressure loss due to the thermal buoyance force induced by tunnel air temperature rise and the impact of thermal buoyance force on the number of jet fans by the numerical fire simulation for the tunnel length(500, 750, 1000, 1500, 2000, 3500m) and grade (-1.0, -1.5, -2.0%). Considering the thermal buoyance force, number of jet fans have to be increased. Especially in the case of 100MW of heat release rate, the pressure loss due to thermal buoyance force exceed the maximum pressure loss due to vehicle drag resistance, so it is analyzed that number of 2~11 jet fans are needed additionally than current design criteria. Thus, in case of estimating the number of jet fans, it must be considered of thermal buoyance force induced tunnel air temperature rise by fire.

• Journal of Veterinary Clinics
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• v.26 no.1
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• pp.1-7
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• 2009

The Artemisia capillaris THUNB is a perennial herb that belongs to the family Compositae spp and probably the most common plant among the various herbal folk remedies being used in the treatment of abdominal pain, hepatitis, chronic liver disease, jaundice and coughing in Korea. Recently the biological and pharmacological actions of herb have been studied well such as antibacterial, antidiabetic and antitumor activities. This experiment was conducted to investigate antitumor and immunomodulatory effects of Artemisia capillaris extracts against Hepa-1c1c7 and Sarcoma 180 cancer cells in in vivo experimental tests. In in vivo experimental tests using 210 ICR mice, based on flow cytometry, CD3+, CD4+, CD8+ and TNF-${\alpha}+$ splenocytes were significantly (p<0.05) reduced in the Hepa-1c1c7 and Sarcoma 180 inoculated vehicle controls, HP and SP, compared to those of the intact vehicle control on both the $28^{th}$ day and the $42^{nd}$ day, respectively. These decreases of CD3+, CD4+, CD8+ and TNF-${\alpha}+$ cells induced by tumor inoculations were significantly (p<0.05) inhibited by mACH treatment regardless of the type of experiments and tumor cells inoculated. The results suggest that Artemisia capillaris methanol extracts have prominent antitumor effects on the cancer cell lines Hepa-1c1c7 and Sarcoma 180.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.1
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• pp.27-33
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• 2022

Functional dyspepsia (FD) is a gastrointestinal disorder with diverse symptoms but no structural or organic manifestations. Benachio-F^® (herein named 'BF-1') is an over-the-counter liquid digestive formulated with multiple herbal extracts, which has been reported to improve symptoms of FD. A total two experiments were conducted. First, we examined whether BF-1 can modulate the progression of FD through two experimental rat models. A total of three doses (0.3x, 1x, 3x of the human equivalent dose) were used. In the gastric emptying model, both 1x (standard) or 3x (3-fold-concentrated) BF-1 enhanced gastric emptying was compared with that of vehicle-treated animals. In a feeding inhibition model induced by acute restraint stress, treatment with 1x or 3x BF-1 led to a similar degree of restoration in food intake that was comparable to that of acotiamide-treated animals. Among the constituents of BF, fennel is known for its choleretic effect. Thus, we next investigated whether a novel BF-based formula (named 'BF-2') that contains an increased amount of fennel extract (3.5-fold over BF-1), has greater potency in increasing bile flow. BF-2 showed a superior choleretic effect compared to BF-1. Furthermore, the postprandial concentration of serum secretin was higher in animals pretreated with BF-2 than in those pretreated with BF-1, suggesting that the increased choleretic effect of BF-2 is related to secretin production. Our results demonstrate that BF-1 can modulate the pathophysiological mechanisms of FD by exerting prokinetic and stress-relieving effects, and that BF-2 has a better choleretic effect than BF-1.

• Journal of Society of Preventive Korean Medicine
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• v.27 no.2
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• pp.23-33
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• 2023

Objectives : Sojadodamgangki-tang and its main components are traditional korean medicinal methods for treatment of cough, sputum and dyspnea. Using a respiratory inflammatory model, we intend to reveal the anti-inflammatory effect and its immune mechanism of Sojadodamgangki-tang. Methods : We used a papain-induced respiratory inflammatory mouse model. 8-week-old female BALB/C mice were divided into 3 groups as follows: the following groups: saline control group, papain treated group (vehicle), papain and Sojadodamgangki-tang(200 mg/kg) treated group (n=4). To evaluate the anti-inflammatory effect of Sojadodamgangki-tang extracts, inflammatory cell infiltration was measured in bronchoalveolar lavage fluid (BALF) and nasal lavage fluid (NALF). In addition, the effects of Sojadodamgangki-tang extracts on Th2 cell population in lung were determined by using flow cytometry. Results : Sojadodamgangki-tang extracts administration reduced inflammatory cell infiltration in BALF and NALF, especially of eosinophils. Furthermore, total immunogloblin (Ig)-E levels was reduced in BALF and serum by drug administration. Interestingly, Sojadodamgangki-tang extracts treatment also decreased the Th2 cell (CD4⁺GATA3⁺) population in lung. Conclusions : Our findings indicate Sojadodamgangki-tang extracts have anti-inflammatory effects by mediating Th2 cell and B cell activation.