• Korean Journal of Animal Reproduction
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• v.17 no.1
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• pp.1-6
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• 1993

This experiment was conducted to determine the effects of gossypol injection spermatogenesis of mice. Gossypol was injected into the stroma of testes(TS) and the doses of gossypol injected were 5, 10 and 15mg per kg of body weights, respectively. The number of sperm and the weight of testes were gradually reduced(P<0.01) from 2 to 4 weeks after gossypol treatment in all groups of mice treated with gossypol, compared with the control group. The rates of malformation(loss of proacrosome, damage of midpiece and breaking of tail) of sperm were significantly(P<0.01) increased at 2 and 3 weeks after the injection of 10 or 15mg of gossypol. However, the weight of testes and the number of normal sperm were gradually increased and the malformation rate of sperm was decreased between 4 and 6 weeks after injection of 5mg of gossypol. The results of this experiment indicated that probably ireeversible suppression of spermatogenesis could be brought about easily and immediately by the single injection of gossypol into TS.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.1 s.106
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• pp.75-80
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• 2006

This paper introduces the mechanism of the ESD(electrostatic discharge) in the HDD spindle system using FDBs(fluid dynamic bearings). When a HDD(hard disk drive) spindle system is rotating, triboelectric charging occurs in the FDBs through the friction between the lubricant and the rotating shaft or between the lubricant and stationary sleeve. And this electrostatic charge is accumulated in the rotating parts of the HDD spindle system because they are insulated from the ground by the lubricant. This research shows experimentally that the behavior of electric charge and discharge in the FDB spindle system is the same as that of a capacitor. It also measures the electrostatic voltage difference between the rotating and stationary parts in the FDB spindle system due to the change of humidity, supporting load and motor speed. This research shows that the control of ESD is required in the HDD spindle system using FDBs, because the electrostatic charge accumulated in the FDB spindle system may cause the breakdown damage of the GMR head and data loss consequently.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.29-34
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• 2005

141,841 car-to-car collision had occurred in 2003, and among the accidents 51,796 were rear-end impact. According to insurance company for loss or damage, more than $60\%$ of rear-end impact victims suffer neck injury. This means at least 31,000 neck injury victims have happened in 2003. More than $97\%$ of the neck injury victims have low severity injury than A.I.S 2. Head restraint, which is designed to limit rearward head movement and equipped on seat, can considerably protect neck from rear-end impact. In this paper we evaluated head restraint geometry and drivers' sitting position according to RCAR standard and carried out low speed volunteer crash test. The crash speed is 4km/h and N.I.C value is used to determine injury probability. Through these research results we can introduce the method to prevent neck injury at rear-end impact.

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.466-473
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• 2019

Angelica gigas has been used as a Korean traditional medicine for pain relief and gynecological health. Although the extracts are reported to have an anti-inflammatory property, the bioactive compounds of the herbal plant and the effect on T cell responses are unclear. In this study, we identified decursinol angelate (DA) as an immunomodulatory ingredient of A. gigas and demonstrated its suppressive effect on type 17 helper T (Th17) cell responses. Helper T cell culture experiments revealed that DA impeded the differentiation of Th17 cells and IL-17 production without affecting the survival and proliferation of CD4 T cells. By using a dextran sodium sulfate (DSS)-induced colitis model, we determined the therapeutic potential of DA for the treatment of ulcerative colitis. DA treatment attenuated the severity of colitis including a reduction in weight loss, colon shortening, and protection from colonic tissue damage induced by DSS administration. Intriguingly, Th17 cells concurrently with neutrophils in the colitis tissues were significantly decreased by the DA treatment. Overall, our experimental evidence reveals for the first time that DA is an anti-inflammatory compound to modulate inflammatory T cells, and suggests DA as a potential therapeutic agent to manage inflammatory conditions associated with Th17 cell responses.

• Safety and Health at Work
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• v.12 no.2
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• pp.184-191
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• 2021

Background: Hearing protection devices (HPDs) are often used in the workplace to prevent hearing damage caused by noise. However, a factor that can lead to hearing loss in the workplace is improper HPD fitting, and the previous literature has shown that instructing workers on how to properly insert their HPDs can make a significant difference in the degree of attenuation. Methods: Two studies were completed on a total of 33 Hydro One workers. A FitCheck Solo field attenuation estimation system was used to measure the personal attenuation rating (PAR) before and after providing one-on-one fitting instructions. In addition, external ear canal diameters were measured, and a questionnaire with items related to frequency of use, confidence, and discomfort was administered. Results: Training led to an improvement in HPD attenuation, particularly for participants with poorer PARs before training. The questionnaire results indicated that much HPD discomfort is caused by heat, humidity, and communication difficulties. External ear canal asymmetry did not appear to significantly influence the measured PAR. Conclusion: In accordance with the previous literature, our studies suggest that one-on-one instruction is an effective training method for HPD use. Addressing discomfort issues from heat, humidity, and communication issues could help to improve the use of HPDs in the workplace. Further research into the effects of canal asymmetry on the PAR is needed.

• The Journal of Pediatrics of Korean Medicine
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• v.35 no.1
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• pp.40-47
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• 2021

Objectives The purpose of this study is to confirm the effect of alleviating inflammation through creating skin fat barrier from Scutellaria baicalensis extract. Methods Four-week-old Balb/C mice were divided into four groups: control group (Ctrl), lipid barrier eliminated group (LBEG), dexamethasone (DM) treated group after lipid barrier elimination (DMTG), and Scutellaria baicalensis (SB) treated group after lipid barrier elimination (SBTG). Scutellaria baicalensis extract were administered for 5 days after removal of the fat barrier. Changes in skin condition, improvement of the fat barrier, and relief of inflammation were observed in each group. Results Compared to LBEG and DMTG, pathological skin damage and tissue changes were less in SBTG, and transepidermal water loss (TEWL) and pH were also significantly reduced. Filaggrin was also significantly increased in SBTG. KLK7, PAR-2, and TSLP in SBTG also showed significant reduction compared to the LBEG and DMTG. Conclusions Scutellaria baicalensis extract restores skin barrier and relieves inflammation through the creation of skin fat barrier. This means that the Scutellaria baicalensis extract can regulate Th2 differentiation through the creation of the epithelial fat barrier.

• BMB Reports
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• v.45 no.3
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• pp.147-152
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• 2012

Methylglyoxal (MG) was identified as an intermediate in non-enzymatic glycation and increased levels were reported in patients with diabetes. In this study, we evaluated the effects of MG on the modification of ferritin. When ferritin was incubated with MG, covalent crosslinking of the protein increased in a time- and MG dose-dependent manner. Reactive oxygen species (ROS) scavengers, $N-acetyl-_L-cysteine$ and thiourea suppressed the MG-mediated ferritin modification. The formation of dityrosine was observed in MG-mediated ferritin aggregates and ROS scavengers inhibited the formation of dityrosine. During the reaction between ferritin and MG, the generation of ROS was increased as a function of incubation time. These results suggest that ROS may play a role in the modification of ferritin by MG. The reaction between ferritin and MG led to the release of iron ions from the protein. Ferritin exposure to MG resulted in a loss of arginine, histidine and lysine residues. It was assumed that oxidative damage to ferritin caused by MG may induce an increase in the iron content in cells, which is deleterious to cells. This mechanism, in part, may provide an explanation or the deterioration of organs under diabetic conditions.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.435-441
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• 2013

A swarm robot system consists of with multiple mobile robots, each of which is called an agent. Each agent interacts with others and cooperates for a given task and a given environment. For the swarm robotic system, the loss of the entire work capability by malfunction or damage to a single robot is relatively small and replacement and repair of the robot is less costly. So, it is suitable to perform more complex tasks. The essential component for a swarm robotic system is an inter-robot collaboration strategy for teamwork. Recently, the swarm intelligence theory is applied to robotic system domain as a new framework of collective robotic system design. In this paper, FA (Firefly Algorithm) which is based on firefly's reaction to the lights of other fireflies and their social behavior is employed to optimize the group behavior of multiple robots. The main application of the firefly algorithm is performed on path planning of swarm mobile robots and its effectiveness is verified by simulations under various conditions.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.435-439
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• 2010

The aim of this study was to evaluate the anti-inlfammatory effects of Glycyrrhiza glabra Linne extract on ulcerative colitis induced by 3% dextran sulfate sodium in mice. The experimental animals were divided into six groups: control(normal), DSS-induced colitis(control), 1 mg/kg, 10 mg/kg, and 100 mg/kg of Glycyrrhiza glabra Linne extract, and 150 mg/kg 5-aminosalicylic acid(5-ASA)(positive control). We evaluated the pathological disease activity index(DAI), change in weight, colon mucosa damage and myeloperoxidase(MPO) in colon mucosa. Treatment with 10 mg/kg and 100 mg/kg of Glycyrrhiza glabra Linne extract led to significant loss of body weight, the decrease of MPO activity and clinical symptoms such as DAI and histological change. In particular, 100 mg/kg Glycyrrhiza glabra Linne extract led to markedly greater improvement than 150 mg/kg 5-ASA treatment. These results suggest that Glycyrrhiza glabra mediated anti-inflammatory action on colorectal sites may be a useful therapeutic approach to ulcerative colitis.

• Journal of Ginseng Research
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• v.35 no.3
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• pp.261-271
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• 2011

Chemical radiation protection is an important strategy to protect living beings against the deleterious effects of radiation. In the present study, the radioprotective effect of hydro-alcoholic extract of Panax ginseng extract (PGR-HAE) was studied on radiation-induced deleterious alterations in Swiss albino mice. Oral administration of such extract (25 mg/kg b wt/day/animal) for 5 consecutive days, half an h. before whole-body exposure to 6 Gy gamma radiation, enhanced the 30 days survival and also inhibited the radiogenic sickness, weight loss and life shortening. PGR-HAE ameliorated radiation induced depletion in blood constituents at different necropsy intervals between 12 h to 30 d, and significantly increased the number of femoral spleen colony forming units that survived after irradiation. Furthermore, it checked depletion of glutathione and antioxidant enzymes (superoxide dismutase, catalase, and glutathione S-transferase) as well as elevation of lipid peroxidation (LPO) level in blood and liver. The significant reduction in the yield of LPO demonstrates that PGR-HAE protects the membranes against radiation-induced oxidative damage. These findings conclude that such plant extract provides significant radioprotection, and it may be potentially valuable in the prevention of injuries caused during planned and unplanned radiation exposure.