• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.243-248
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• 2008

Moisture damage of asphalt pavements can usually occur because of the loss of adhesion and cohesion between the asphalt binder and aggregate in the asphalt mixture due to presence of water. And this is one of the causes that is effect on the main distress of asphalt pavement. The objective of this study is to find out moisture damage characteristics of asphalt pavement. Effects of this study changes of the material properties and resistance characteristics of moisture damage on the asphalt mixtures under various temperatures and repeated immersion using indirect tensile test and modify Lottman test were evaluated during this study. The asphalt mixtures were produced using straight asphalt binder, SBS modified asphalt binder and aggregates. The material properties (resilient modulus, indirect tensile strength, failure energy and $DCSE_f$) of the asphalt mixtures were generally decreased with increasing to moisture damage caused by the number of repeated immersion. The decrease ratios of material properties by repeated immersion on SBS modified asphalt mixtures were lower than those of straight asphalt mixtures at all three test temperatures. As a conclusion, current criterion for evaluation moisture damage of asphalt mixtures is difficult for using distinction standard because of the limited evaluation criterion with one time immersion and single material property. Based on this research, to evaluate long term moisture damage on asphalt mixtures, material property tests of various kinds with repeated immersion test are considered.

• The Journal of Internal Korean Medicine
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• v.45 no.1
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• pp.11-30
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• 2024

Objectives: This study evaluated the effects of Ssanghwa-tang (SHT) on lung injury and muscle loss in a COPD mouse model. Methods: C57BL/6 mice were challenged with cigarette smoke extract and lipopolysaccharide, and then treated with two concentrations of SHT (250 and 500 mg/kg). After sacrifice, the bronchoalveolar lavage fluid (BALF) or lung tissue was analyzed by cytospin, ELISA, real-time PCR, flow cytometry analysis, and H&E and Masson's trichrome staining. The grip strength of COPD mice was measured using a grip strength meter. The running time of COPD mice was measured by a treadmill test. Muscle tissue of the quadriceps was stained with H&E and Masson's trichrome staining. Results: SHT significantly inhibited the increase in neutrophil numbers in BALF and significantly decreased immune cell activity in BALF and lung tissue. It also significantly inhibited the increase in TNF-α, IL-17, and MIP2 in BALF. Real-time PCR analysis revealed that the mRNA expression of TNF-α, IL-17, MIP2, and TRPV1 in lung tissue showed a significant decrease compared with the control group. Lung tissue damage was significantly reduced in the histological analysis. The grip strength and running time of the COPD mice showed a significant decrease compared with the control group. In histological staining, SHT was found to reduce the damage to muscle tissue. Conclusions: This study indicates that SHT can be used as a therapeutic agent for COPD patients by inhibiting lung injury and muscle loss.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.79-85
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• 2020

Background: Helicobacter pylori increases reactive oxygen species (ROS) and induces oxidative DNA damage and apoptosis in gastric epithelial cells. DNA damage activates DNA damage response (DDR) which includes ataxia-telangiectasia-mutated (ATM) activation. ATM increases alternative reading frame (ARF) but decreases mouse double minute 2 (Mdm2). Because p53 interacts with Mdm2, H. pylori-induced loss of Mdm2 stabilizes p53 and induces apoptosis. Previous study showed that Korean Red Ginseng extract (KRG) reduces ROS and prevents cell death in H. pylori-infected gastric epithelial cells. Methods: We determined whether KRG inhibits apoptosis by suppressing DDRs and apoptotic indices in H. pylori-infected gastric epithelial AGS cells. The infected cells were treated with or without KRG or an ATM kinase inhibitor KU-55933. ROS levels, apoptotic indices (cell death, DNA fragmentation, Bax/Bcl-2 ratio, caspase-3 activity) and DDRs (activation and levels of ATM, checkpoint kinase 2, Mdm2, ARF, and p53) were determined. Results: H. pylori induced apoptosis by increasing apoptotic indices and ROS levels. H. pylori activated DDRs (increased p-ATM, p-checkpoint kinase 2, ARF, p-p53, and p53, but decreased Mdm2) in gastric epithelial cells. KRG reduced ROS and inhibited increase in apoptotic indices and DDRs in H. pylori-infected gastric epithelial cells. KU-55933 suppressed DDRs and apoptosis in H. pylori-infected gastric epithelial cells, similar to KRG. Conclusion: KRG suppressed ATM-mediated DDRs and apoptosis by reducing ROS in H. pylori-infected gastric epithelial cells. Supplementation with KRG may prevent the oxidative stress-mediated gastric impairment associated with H. pylori infection.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.3
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• pp.211-220
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• 2021

Objective: The present study aimed to investigate the possibility that curcumin (CMN) protects against methotrexate (MTX)-induced testicular damage by affecting the phospho-p38 (p-p38) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. Methods: Eighteen male Wistar albino rats were randomly divided into three groups. The control group was given an intragastric administration of dimethyl sulfoxide (DMSO) daily for 14 days, the MTX group was given a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day, and the MTX+CMN group was given intragastric CMN (100 mg/kg/day, dissolved in DMSO) for 14 days and a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day. At the end of the experiment, all animals were sacrificed and the testicular tissues were removed for morphometry, histology, and immunohistochemistry. Body and testicular weights were measured. Results: Body weights, seminiferous tubule diameter, and germinal epithelium height significantly decreased in the MTX group compared to the control group. Whereas, the number of histologically damaged seminiferous tubules and interstitial space width significantly increased in the MTX group. In addition, the number of p-p38 MAPK immunopositive cells and the immunoreactivity of NF-κB also increased in the MTX group compared to the control group. CMN improved loss of body weight, morphometric values, and histological damage due to MTX. CMN also reduced the number of p-p38 MAPK immunopositive cells and the NF-κB immunoreactivity. Conclusion: CMN may reduce MTX-induced testicular damage by suppressing the p38 MAPK and NF-κB signaling pathways.

• Journal of Ginseng Research
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• v.46 no.1
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• pp.115-125
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• 2022

Background: Ginsenosides (GS) have potential value as cosmetic additives for prevention of skin photoaging. However, their protective mechanisms against skin barrier damage and their active monomeric constituents are unknown. Methods: GS monomer types and their relative proportions were identified. A UVB-irradiated BALB/c hairless mouse model was used to assess protective effects of GS components on skin epidermal thickness and transepidermal water loss (TEWL). Skin barrier function, reflected by filaggrin (FLG), involucrin (IVL), claudin-1 (Cldn-1), and aquaporin 3 (AQP3) levels and MAPK phosphorylation patterns, were analyzed in UVB-irradiated hairless mice or HaCaT cells. Results: Total GS monomeric content detected by UPLC was 85.45% and was largely attributed to 17 main monomers that included Re (16.73%), Rd (13.36%), and Rg1 (13.38%). In hairless mice, GS ameliorated UVB-induced epidermal barrier dysfunction manifesting as increased epidermal thickness, increased TEWL, and decreased stratum corneum water content without weight change. Furthermore, GS treatment of UVB-irradiated mice restored protein expression levels and epidermal tissue distributions of FLG, IVL, Cldn-1, and AQP3, with consistent mRNA and protein expression results obtained in UVB-irradiated HaCaT cells (except for unchanging Cldn-1 expression). Mechanistically, GS inhibited JNK, p38, and ERK phosphorylation in UVB-irradiated HaCaT cells, with a mixture of Rg2, Rg3, Rk3, F2, Rd, and Rb3 providing the same protective MAPK pathway inhibition-associated upregulation of IVL and AQP3 expression as provided by intact GS treatment. Conclusion: GS protection against UVB-irradiated skin barrier damage depends on activities of six ginsenoside monomeric constituents that inhibit the MAPK signaling pathway.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.133-138
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• 2024

Lithium-ion batteries are used in many fields due to their high energy density, fast charging conditions, and long cycle life. However, overcharging, over-discharging, physical damage, and use of lithium-ion batteries at high temperatures can reduce battery life and cause damage to people due to fire or explosion due to damage to the protection circuit. In order to reduce the risk of these batteries and improve battery performance, the characteristics of the charging and discharging process must be analyzed and understood. Therefore, in this paper, we analyze the charging and discharging characteristics of lithium-ion batteries using a battery charger and discharger and simulator to reduce the risk of loss of life due to overcharge and overdischarge, as well as casualties from fire and explosion due to damage to the protection circuit.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.482-488
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• 2011

Cadmium (Cd) is well known as a spermatotoxic and gonadotoxic heavy metal ion. This study was performed to assess the possible protective effect of Enerbalance on Cd-induced spermiotoxicity and testicular damage. The control group received isotonic saline; Cd group received Cd (2 mg/kg BW per day) orally; extract-treated groups were orally administrated with Enerbalance (50 mg and 100 mg/kg BW per day) and Cd for 10 days. Morphological changes of testicular tissue, sperm characteristics, oxidative/antioxidative parameters from testis, and serum sexual hormone level were determined. Enerbalance was significantely increased sperm amount in cauda epididymis without changes of ratio of epididymis/body weight and testis/body weight. Cd caused a marked decrease in epididymal sperm concentration and chemotactic sperm motility, testicular superoxide dismutase (SOD), catalase (CAT), Enerbalance was significantly ameliorated loss of epididymal sperm concentration, sperm chemotactic motility, antioxidative parameters, and male hormone whereas decreased abnormal architecture by testis damage. Enerbalance was successfully attenuated these adverse effects of Cd and offers a dose-dependent protection. Our study demonstrated that Enerbalance could proffer a measure of protection against Cd-induced testicular damage and spermiotoxicity by possibly reducing oxidative stress and increasing the antioxidant defense mechanism in mice.

• Fire Science and Engineering
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• v.15 no.1
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• pp.116-126
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• 2001

Fire investigation to examine ignition and combustion enlargement etc., to assess fire damage and to investigate a fire suspect, is used as a valuable data for better fire suppression and fire prevention police. Fire investigation is divided in to fire-cause investigation, fire-damage investigation, and fire-criminal investigation. At present, fire-cause investigation is lacking In scientific technology; specially is deficient in accurate damage assessment. And considering fore criminal investigation, since the police lacking in specialty on fire take exclusive charge of fire criminal investigation upon general investigation, it is difficult to investigate fire criminal effectively. Finally deficiency in fire investigation operates as very big blind-spot in fire safety having important axis in social safely; the loss is shifted on nation's shoulder. To solve those problems, legal, institutional, operational preparation is urgent. And so, this study tried to stabilize specialty of fire-fighting to offer more active, qualitative fire administration service, and to contribute to public peace and welfare by grasping problems after diagnosing Korean fire investigation and proposing the solutions.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.391-398
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• 2002

During handling unitized products, they are subjected to a variety of environmental hazards. Shock and vibration hazards are generally considered the most damaging of the environmental hazards on a product and it may encounter while passing through the distribution environment. A major cause of shock damage to products is drops during manual handling. The increasing use of unitization of pallets has been resulted in a reduction of the shock hazards. This has caused an increasing interest in research focused on vibration caused dam age. Damage to the product by the vibration most often occurs when a product or a product component has a natural frequency that falls within the range of the forcing frequencies of the particular mode of transportation being used. Transportation vibration is also a major cause of fruit and vegetable quality loss due to mechanical damage. This study was conducted to determine the vibration characteristics of the corrugated fiberboard bones for packages of pears, and to investigate the degree of vibration injury of the pears in the boxes during the simulated transportation environment. The vibration tests were performed on an electrohydraulic vibration exciter. The input acceleration to exciter was fixed at 0.25 G for a single container resonance test and 0.5 G for the vertical stacked container over the frequency range from 3 to 100 Hz. Function generator (HP-33120A) was connected by wire to the vibration exciter for controlling the input acceleration at a continuous logarithmic sweep rate of 1.0 octave per min. The peak frequency and acceleration on the single box test were 22.02 Hz, 1.5425 G respectively, and these values on the vertical stacked boxes were observed from the bottom box 19.02, 18.14, 16.62 and 15.40 Hz and 2.2987, 3.7654. 5.6087, and 7.9582 G, respectively. The pear in the bottom box had a slightly higher damage level than the fruit packed in the other stacked boxes. It is desirable that the package and transportation system has to be so designed that 15∼20 Hz frequency will not occur during the transportation environment.

• Fire Science and Engineering
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• v.23 no.3
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• pp.110-120
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• 2009

In tunnel, though the frequency of fire occurrence is relatively lower than other structures, the characteristics of sealed space tends to cause the temperature to rapidly rise to more than $1000^{\circ}C$ within 5minutes after fire, which might eventually lead to a large fire that usually results in a loss of lives and the damage to the properties, not to mention a huge cost necessary for repair and maintenance after fire. We have developed various conditions of the heating furnace and the method to install a thermo couple within the furnace based on EFNARC and KS F 2257-1. Referring to tunnel fire scenarios, it clarified the heat transfer characteristics of concrete PC panel lining depending on fire intensity (ISO, $1^{\circ}C$/SEC, MHC, RWS), and to identify the range of thermal damage, the evaluation was carried out using ITA standard. As a result, 30mm under ISO fire condition, 20mm under $1^{\circ}C$/SEC, 100mm under MHC and 50mm under RWS were measured. And when it comes to spalling, 30mm was measured under RWS and MHC.