• Computers and Concrete
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• v.7 no.4
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• pp.365-386
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• 2010

This paper presents the physical formulation of a 1D material model suitable for seismic applications. It is written within the framework of thermodynamics with internal variables that is, especially, very efficient for the phenomenological representation of material behaviors at macroscale: those of the representative elementary volume. The model can reproduce the main characteristics observed for concrete, that is nonsymetric loading rate-dependent (viscoelasticity) behavior with appearance of permanent deformations and local hysteresis (continuum plasticity), stiffness degradation (continuum damage), cracking due to displacement localization (discrete plasticity or damage). The parameters have a clear physical meaning and can thus be easily identified. Although this point is not detailed in the paper, this material model is developed to be implemented in a finite element computer program. Therefore, for the benefit of the robustness of the numerical implementation, (i) linear state equations (no local iteration required) are defined whenever possible and (ii) the conditions in which the presented model can enter the generalized standard materials class - whose elements benefit from good global and local stability properties - are clearly established. To illustrate the capabilities of this model - among them for Earthquake Engineering applications - results of some numerical applications are presented.

• Journal of the Korean Institute of Gas
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• v.7 no.4 s.21
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• pp.53-60
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• 2003

Accident occurred by gas explosion in house or building causes damage on lives and properties. To avoid secondary damage, this study drew area ratio of vent area with the experiment for pressure variation with vent area versus building volume by selection of model for different size and shapes of vent area generated by explosion. In addition, Appropriate model was chosen to predict the damage by minimum pressure with the experiment of opening are shapes. This model can prevent secondary damage with the selected vent area and shape to guarantee building safety.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.527-534
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• 2006

This study estimated the forest damage of Kangwon-Do fire disaster occurred April 2005. For the estimation, the delineation of fire damaged area was performed using SPOT-4 satellite image and DSM (Digital surface model)/DTM (Digital Terrain Model) was generated by airborne and ground LiDAR data to calculate forests height. The damaged amount of money was calculated in forest area using stand volume formula, combining the canopy height from forest height model and digital stock map. The total forest damage amounted to 3.9 billion won.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.5
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• pp.423-431
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• 2020

This study aimed to evaluate the effect of curcumin on brain hypoxic-ischemic (HI) damage in neonatal rats and whether the phosphoinositide 3-kinase (PI3K)/Akt/vascular endothelial growth factor (VEGF) signaling pathway is involved. Brain HI damage models were established in neonatal rats, which received the following treatments: curcumin by intraperitoneal injection before injury, insulin-like growth factor 1 (IGF-1) by subcutaneous injection after injury, and VEGF by intracerebroventricular injection after injury. This was followed by neurological evaluation, hemodynamic measurements, histopathological assessment, TUNEL assay, flow cytometry, and western blotting to assess the expression of p-PI3K, PI3K, p-Akt, Akt, and VEGF. Compared with rats that underwent sham operation, rats with brain HI damage showed remarkably increased neurological deficits, reduced right blood flow volume, elevated blood viscosity and haematocrit, and aggravated cell damage and apoptosis; these injuries were significantly improved by curcumin pretreatment. Meanwhile, brain HI damage induced the overexpression of p-PI3K, p-Akt, and VEGF, while curcumin pretreatment inhibited the expression of these proteins. In addition, IGF-1 treatment rescued the curcumin-induced down-regulated expression of p-PI3K, p-Akt, and VEGF, and VEGF overexpression counteracted the inhibitory effect of curcumin on brain HI damage. Overall, pretreatment with curcumin protected against brain HI damage by targeting VEGF via the PI3K/Akt signaling pathway in neonatal rats.

• BMB Reports
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• v.57 no.2
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• pp.98-103
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• 2024

The mammalian sirtuin family (SIRT1-SIRT7) has shown diverse biological roles in the regulation and maintenance of genome stability under genotoxic stress. SIRT7, one of the least studied sirtuin, has been demonstrated to be a key factor for DNA damage response (DDR). However, conflicting results have proposed that Sirt7 is an oncogenic factor to promote transformation in cancer cells. To address this inconsistency, we investigated properties of SIRT7 in hepatocellular carcinoma (HCC) regulation under DNA damage and found that loss of hepatic Sirt7 accelerated HCC progression. Specifically, the number, size, and volume of hepatic tumor colonies in diethylnitrosamine (DEN) injected Sirt7-deficient liver were markedly enhanced. Further, levels of HCC progression markers and pro-inflammatory cytokines were significantly elevated in the absence of hepatic Sirt7, unlike those in the control. In chromatin, SIRT7 was stabilized and colocalized to damage site by inhibiting the induction of γH2AX under DNA damage. Together, our findings suggest that SIRT7 is a crucial factor for DNA damage repair and that hepatic loss-of-Sirt7 can promote genomic instability and accelerate HCC development, unlike early studies describing that Sirt7 is an oncogenic factor.

• The Journal of Korean Medicine
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• v.22 no.1
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• pp.10-21
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• 2001

Objective : This study was performed to investigate the protective effect of Stephania tetrandra(ST) against ischemic brain damage after a middle cerebral artery(MCA) occlusion. The effect was evaluated using histological tests, neurobehavioral tests, and biochemical tests. Methods : Rats(Sprague-Dawley) were divided into four groups : sham operated group, MCA occluded group, post MCA occlusion Stephania tetrandra administrated (7.6mg/l00g) group, and normal group. The MCA was occluded by intraluminal method. Stephania tetrandra was administrated orally twice at 1 and 4 hours after MCA occlusion. The neurobehavioral test was performed at 3, 6, 9 and 24 hours after MCA occlusion by posture reflex test and swimming behavioral test. All groups were sacrificed then. The brain tissues were stained with 2% triphenyl tetrazolium chloride(TTC) or 1 % cresyl violet solution, to examine infarct size, volume and cell number. Tumor necrosis $factor-{\alpha}$ level was measured from sera using Enzyme-Linked Immunoabsorbent Assay(ELISA). The mRNA expression level of inflammatory cytokines and related receptor type I and II, $IL-1{\beta}$, IL-6, and IL-10 6hours after MCA occlusion were also studied by reverse transcriptase polymerase chain reaction(RTPCR). Results : The results showed that : Stephania tetrandra (1) reduced infarct size and total infarct volume by 52.2% compared to the control group; (2) attenuated significantly in neuronal death, which was shown by a decrease in cell number(P<0.01) and size(P<0.01) in the boundary area of the infarction; (3) significantly reduced serum $TNF-{\alpha}$ level, and increased the mRNA level of IL-10 in the cortex region(P<0.01). However, there was no significant effect on motor deficit in swimming behavioral test. Conclusions : In conclusion, Stephania tetrandra has protective effects against ischemic brain damage at the early stage of ischemia.

• Journal of Korean Society of Forest Science
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• v.107 no.3
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• pp.278-286
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• 2018

This study examined the damage characteristics through investigation for a total of 10 factors (longitudinal position, crossing position, soil type, collecting well volume, outlet position, water apron material, waterway existence, pipe culvert diameter, pipe culvert gradient, pipe culvert height) affecting outlet damages of forest road cross drainage for forest roads in the Research Forest of Kangwon National University. We predicted outlet damages of forest road cross drainage for forest roads using a discriminant analysis Results showed that longitudinal position, crossing position, soil type and pipe culvert height did not affect damages caused to forest road cross drainage. Most influential factors affecting outlet damages were outlet position, waterway existence, pipe culvert diameter, pipe culvert gradient and collecting well volume, respectively. The discriminant ratio calculated from the developed discriminant function was 68.8% which is reasonably reliable.

• The Korea Journal of Herbology
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• v.29 no.5
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• pp.23-30
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• 2014

Objectives : Dodam-tang has been reported to have a control effect against the hyperlipidemia and thrombosis. Based upon these previous reports, this study investigates the effects of Dodam-tang on the cerebral ischemic damage of the hyperlipidemic rats. Methods : Hyperlipidemia was induced by the beef tallow 30% diet for 14 days on Sprague-Dawley rats. Ischemic damage was induced by the middle cerebral artery occlusion (MCAO) for 2 hours with the intraluminal thread method. Then water extract of Dodam-tang was administered daily for 5 days. The effect of Dodam-tang was evaluated with the serum lipids, infarct volume and edema percentage, and immunohistochemical expressions of iNOS, MMP-9, and GFAP in the brain tissue. Results : The obtained results were as follows; Dodam-tang reduced significantly the infarct size in a TTC-stained 5th brain section of the hyperlipidemic MCAO rats. Dodam-tang suppressed the infarct volume of the hyperlipidemic MCAO rats, but not significant statistically. Dodam-tang suppressed the edema percentage of the hyperlipidemic MCAO rats significantly in the brain tissue. Dodam-tang suppressed significantly the iNOS expression in the cerebral penumbra and caudate putamen of the hyperlipidemic MCAO rats. Dodam-tang suppressed significantly the MMP-9 expression in the cerebral penumbra of the hyperlipidemic MCAO rats. Dodam-tang suppressed significantly the GFAP-expressed atrocytes in the cerebral penumbra of the hyperlipidemic MCAO rats. Conclusions : These results suggest that Dodam-tang suppresses the brain edema formation through the suppression of the iNOS, MMP-9 and GFAP, but the neuroprotective effect against the cerebral infarct are not distinct.

• The Journal of Korean Medicine
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• v.22 no.1
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• pp.78-89
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• 2001

Objectives : The purpose of this investigation is to evaluate the effects of Woohwangcheongsim-won on reperfusion following MCA occlusion in rats. Methods : To evaluate the effect of Woohwangcheongsim-won on reperfusion following MCA occlusion, the volume of cerebral ischemia and edema were measured and the change of the CAI pyramidal neuron in the hippocampus was investigated by light microscopy. And the changes of several neurotransmitters and enzymes were investigated with the immunohistochemical methods. Results : 1. The volume of the control group, which was ischemic-damaged was 23.6%, and that of the sample group was 13.5%. 2. The voluminalratio of the right/left hemisphere was 116 in the control group, and that of the sample group was 107. 3. The pyramidal cells of CAI area in the control group were greatly damaged. The cells were changed into discontinuous and unsystematic forms, and nuclei, and cytoplasms were shrunk. On the other hand, the cells of the sample group were less damaged. 4. On the immunohistochemical methods, the sensitivities of GABA, NOS, DBH in the control group were increased, and those of synapsin and $eEF-l{\alpha}$ were decreased as compared with the normal group. NOS and DBH which were negative in the normal group showed positive reaction. On the other hand, the sensitivities of GABA, NOS and DBH in the sample group were decreased, but those of NPY, synapsin, CaMKII and $eEF-l{\alpha}$ were increased as compared with the control group. Conclusions : Woohwangcheongsim-won reduced the volume of cerebral ischemia and edema, and minimized the damage of pyramidal cells. The mechanism was related to protein synthesis, such as synapsin, ${\alpha}CaMKII$ and $eEF-l{\alpha}$, which resist neurotoxicity of glutamate receptors.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.151-156
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• 2008

The annals of Joseon Dynasty is the most valuable resource containing the record of Korean history and has been known as one of the UNESCO's Memory of the World Register. There was a period that the annals of Joseon Dynasty was used with beeswax to control pests. It is considered as the prior reason of damage on the annals of Joseon Dynasty. Therefore, in this study we analysed the spectrum of traditional paper inside and outside of Korea, beeswax and accelerated artificial aging paper to restore the waxed volume in the annals of Joseon Dynasty by using FT-IR. As a result of FT-IR analysis, spectrum did not showed its big difference in all paper used in this study. However, there was a different spectrum in paper which was made with not Broussonetia kazinoki, but Echinochloa crus-galli var. frumentacea and Dioscorea batatas. Among traditional papers in various countries, spectrum of Korean paper showed the most similarity from the annals of Joseon Dynasty. In comparison between accelerated artificial aging paper and waxed volume, we could identify the change of spectrum affected by the damage.