• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.230-236
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• 2009

An extract of Allomyrina dichotoma larva (ADL), one of the insects used most frequently in traditional Chinese medicine for the treatment of liver diseases such as hepatocirrhosis and hepatofibrosis, was assessed for antioxidant bioactivity in this study. In the current work, we have investigated the protective effects of ADL extracts on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in cultured hepa1c1c7 cells and in the mouse liver. The treatment of the hepa1c1c7 cells with ADL extracts induced a significant reduction of t-BHP-induced oxidative injuries, as determined by cell cytotoxicity, lipid peroxidation (LPO) and reactive oxygen species contents, in a dose-dependent manner. Moreover, ADL extracts evidenced a protective effect against t-BHPinduced oxidative DNA damage, as revealed by the results of the Comet assay in hepa1c1c7 cells. ADL extracts also protected against hydroxyl radical-induced 2-deoxy-d-ribose degradation by ferric ion-nitrilotriacetic acid and $H_2O_2$. In addition, ADL extracts were shown to be able to quench 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Our in vivo study revealed that ADL extracts pretreatment applied prior to t-BHP administration significantly prevented an increase in the serum levels of hepatic enzyme markers and reduced LPO in the mouse liver in a dose-dependent manner. Taken together, these results suggest that the protective effects of ADL extracts against t-BHP-induced hepatotoxicity may be attributable, at least in part, to its ability to scavenge free oxygen radicals, and to protect against DNA damage due to oxidative stress.

• Safety and Health at Work
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• v.4 no.2
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• pp.105-110
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• 2013

Background: To determine the influence of lifting speed and type on peak and cumulative back compressive force (BCF) and shoulder moment (SM) loads during symmetric lifting. Another aim of the study was to compare static and dynamic lifting models. Methods: Ten male participants performed a floor-to-shoulder, floor-to-waist, and waist-to-shoulder lift at three different speeds [slow (0.34 m/s), medium (0.44 m/s), and fast (0.64 m/s)], and with two different loads [light (2.25 kg) and heavy (9 kg)]. Two-dimensional kinematics and kinetics were determined. A three-way repeated measures analysis of variance was used to calculate peak and cumulative loading of BCF and SM for light and heavy loads. Results: Peak BCF was significantly different between slow and fast lifting speeds (p < 0.001), with a mean difference of 20% between fast and slow lifts. The cumulative loading of BCF and SM was significantly different between fast and slow lifting speeds (p < 0.001), with mean differences ${\geq}80%$. Conclusion: Based on peak values, BCF is highest for fast speeds, but the BCF cumulative loading is highest for slow speeds, with the largest difference between fast and slow lifts. This may imply that a slow lifting speed is at least as hazardous as a fast lifting speed. It is important to consider the duration of lift when determining risks for back and shoulder injuries due to lifting and that peak values alone are likely not sufficient.

• Culinary science and hospitality research
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• v.15 no.1
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• pp.296-308
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• 2009

According to Lee In-ja's research into the cooks of Korea, there are more than 1.2 million culinary professionals in Korea. However, it is hard to find studies on their work environment. From this point, this study aims to examine the shoes worn by culinarians in their workplace and facilitate the improved environment to protect culinary professionals against potential dangers such as slips, occupational and industrial injuries and fatigue, on the basis of the shoes they wear. The research was conducted on a representative cross section of safety shoes currently worn by culinary professionals. The four factors to be tested and measured for the study were weight, slip resistance, internal tearing strength and splitting resistance. Findings on inquiry showed that the shoes tested were quite heavy, slippery and readily liable to splitting under low stress - when compared to standardized base figures. In accordance with the results of this experiment, guidelines for four factors of manufacture were suggested. First, chef's shoes should weigh not more than 1% of a wearers weight. Second, they should exhibit more than 0.50 $\mu$ slip resistance. Third, they should withstand at least 50.0 N/mm tearing strength. And finally, they should have upwards of 3.0 kg/cm splitting resistance.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.32-38
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• 2009

According to the statistics from the Ministry of labor, 70~80 people died by work-related electric shock accidents in the workplace and this number is about 10~20 times higher than those of the foreign countries such as Japan and the United Kingdom in frequencies and rates per 100,000. The electrocution deaths had decreased from several hundred in 1990s to 67 in 2002, since then there has been little change over the last 5 years. To reduce this number of the electrocution death, it is necessary to analyze the sources of the accidents and to implement the suitable measures for preventing the similar accidents from occurring. But there is not any consensus standard method or procedures for accident investigation yet. And the results solely depend on the ability of the investigator. Because of the demand of eliminating technical barrier for free trading, the IEC 60364 is adopted as a regulation for low voltage electrical installations in Korea. The facilities designed and constructed by IEC 60364 are increasing. The facilities by IEC 60364 have different features in comparison with the facilities by Korea eletro technical regulation, and these features combined with parameters of electric shock accident can greatly affect the consequences of the electric accidents. The accident analysis program for electric shock injuries in Terra Neutral(TN) and Terra Terra(TT) system was developed in this paper, which was based on KOSHA Electric Shock Analysis Program(ESAP).

• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.147-152
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• 2013

PURPOSE. A survey was performed to identify the level of mouthguard use, awareness, wearability issues and attitude toward mouthguard among elite Korean Taewondo athletes. MATERIALS AND METHODS. Survey questionnaires were given to 152 athletes participating in the Korea National Taekwondo team selection event for the 2010 Guangzhou Asian Games. Questionnaires consisted of three sections, mouthguard awareness, reasons for not wearing mouthguard and the last section to test the level of acceptance on current mouthguard and when the identified problems were resolved. For analyzing difference among response, ${\chi}^2$ test was used and significant level (${\alpha}$) was set up as 0.05. RESULTS. Responses in each of items showed significant difference (P<.001). Majority of response regarding each question: Majority of respondents believed that mouthguard were effective in preventing injuries (36.4%) but the result suggested that the provision of information on mouthguard to athletes was inadequate (44.0%) and the result showed that respondents were not greatly interested or concerned in relation to the mandatory mouthguard rule (31.6%). Although the responses on the level of comfort and wearability of mouthguard were negative (34.8%), athletes were positively willing to wear mouthguard if the problems rectified (51.2%). CONCLUSION. Considering the high level of willingness to wear mouthguard if the problems rectified, it is thought that together with efforts in providing more mouthguard information, the work of sports dentistry to research and improve mouthguard will be invaluable in promoting mouthguard to more athletes.

• Physical Therapy Rehabilitation Science
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• v.2 no.1
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• pp.12-20
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• 2013

Objective: To determine the energy consumed and muscle use during dance compared to different standard exercise devices. Design: Longitudinal study. Methods: Fifteen female subjects were evaluated to assess the energy cost and muscle activity during a 20 minute dance video compared to treadmill, elliptical track and bicycle ergometry. The later 3 forms of exercise were accomplished in four, 5 minute bouts at different intensities of exercise. Subjects were in the age range of 22-24 years old, were free of cardiovascular disease and did not have any neurological injuries. They were not sedentary and exercised at least twice a week. During the exercise, muscle activity was measured by the electromyogram recorded by surface electrodes on 6 muscle groups. A Cosmed metabolic cart was used to measure oxygen consumption during the exercise. Results: The aerobic dance video that was tested here was equivalent to a hard workout on any of the 3 exercise modalities. The dance routine was equivalent in terms of energy consumed to running at 225 watts of work or running for 20 minutes at a speed of 2 meters per second (4.47 miles per hour). Compared to the bicycle, it was equivalent to cycling at 112 watts for 20 minutes (2.25 kpm), and for the elliptical trainer, dance was equivalent to 435 watts. Concerning muscle use, the dance routine was the most balanced for upper, core and lower body muscles. Although the elliptical trainer was close, it required muscle less muscle use. Conclusion: A good dance video can be more effective than standard exercise equipment.

• Journal of the Korean Society of Safety
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• v.26 no.1
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• pp.49-57
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• 2011

A questionnaire study was carried out to understand the status of performing the risk assessment of work-related musculoskeletal disorders(WMDSs), which is the employers' legal responsibility when the employees are involved in doing tasks with risk factors. Employers or managers from 340 companies and the representative employees from 250 companies participated in the survey. According to the participated employers and employees, 35.0~46.2% of companies had performed the first risk assessment before the end of 2005. However, it is presumed that the real condition might not be as much as the result, because most companies were very reluctant to took part in the survey. It was found that the type of business and size of the company are the main factors affecting the performance of the risk assessment in terms of the performing ratio, method, and so on. The participants were positive in the thought that the assessment would be helpful in preventing msuculoskeletal disorders, while there was a little difference between the employers and employees in the thought that the assessment would be helpful in finding the injuries in the early stage. It was found that it is necessary to modify and improve the definition and criteria of the tasks to be examined in the assessment.

• Safety and Health at Work
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• v.7 no.1
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• pp.32-37
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• 2016

Background: Previous research has shown that paramedics are exposed to risks in the form of injuries to the musculoskeletal system. In addition, there are studies showing that they are also at increased risk of cardiovascular disease, cancer, and psychiatric diseases, which can partly be explained by their constant exposure to stress. The aim of this study is to evaluate whether the use of shoulder straps decreases physical effort in the form of decreased heart rate and cortisol concentration. Methods: A stretcher with a dummy was carried by 20 participants for 400 m on two occasions, one with and one without the shoulder straps. Heart rate was monitored continuously and cortisol samples were taken at intervals of 0 minutes, 15 minutes, 30 minutes, 45 minutes, and 60 minutes. Each participant was her or his own control. Results: A significant decrease in heart rate and cortisol concentration was seen when shoulder straps were used. The median values for men (with shoulder straps) at 0 minutes was 78 bpm/21.1 nmol/L (heart rate/cortisol concentration), at 15 minutes was 85 bpm/16.9 nmol/L, and at 60 minutes was 76 bpm/15.7 nmol/L; for men without shoulder straps, these values were 78 bpm/21.9 nmol/L, 93 bpm/21.9 nmol/L, and 73 bpm/20.5 nmol/L. For women, the values were 85 bpm/23.3 nmol/L, 92 bpm/20.8 nmol/L, and 70 bpm/18.4 nmol/L and 84 bpm/32.4 nmol/L, 100 bpm/32.5 nmol/L, and 75 bpm/25.2 nmol/L, respectively. Conclusion: The use of shoulder straps decreases measurable physical stress and should therefore be implemented when heavy equipment or a stretcher needs to be carried. An easy way to ensure that staff use these or similar lifting aids is to provide them with personalized, well-adapted shoulder straps. Another better option would be to routinely sewn these straps into the staff's personal alarm jackets so they are always in place and ready to be used.

• Safety and Health at Work
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• v.9 no.1
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• pp.42-52
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• 2018

Background: Maintenance operations on-board ships are highly demanding. Maintenance operations are intensive activities requiring high man-machine interactions in challenging and evolving conditions. The evolving conditions are weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress. For example, extreme weather condition affects seafarers' performance, increasing the chances of error, and, consequently, can cause injuries or fatalities to personnel. An effective human error probability model is required to better manage maintenance on-board ships. The developed model would assist in developing and maintaining effective risk management protocols. Thus, the objective of this study is to develop a human error probability model considering various internal and external factors affecting seafarers' performance. Methods: The human error probability model is developed using probability theory applied to Bayesian network. The model is tested using the data received through the developed questionnaire survey of >200 experienced seafarers with >5 years of experience. The model developed in this study is used to find out the reliability of human performance on particular maintenance activities. Results: The developed methodology is tested on the maintenance of marine engine's cooling water pump for engine department and anchor windlass for deck department. In the considered case studies, human error probabilities are estimated in various scenarios and the results are compared between the scenarios and the different seafarer categories. The results of the case studies for both departments are also compared. Conclusion: The developed model is effective in assessing human error probabilities. These probabilities would get dynamically updated as and when new information is available on changes in either internal (i.e., training, experience, and fatigue) or external (i.e., environmental and operational conditions such as weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress) factors.

• Journal of Korean Neurosurgical Society
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• v.39 no.4
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• pp.271-276
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• 2006

Objective : Despite the recent progress that has been made in intracerebral monitoring, it is still difficult to quantify the exact extent of primary brain damage after severe head injury. In this work, we investigate the role of S-100B protein as a serum marker of brain damage after severe head injury. Methods : 21 patients with severe head injury [GCS score <9] were selected for this prospective study. A venous blood sample was taken as soon as possible after head injury and the serum concentration of S-100B protein was measured daily for five consecutive days. The serum level of S-100B protein was compared with the patients' outcome. The outcome was measured twice, at hospital discharge and after 6 months of follow-up using the Glasgow Outcome Scale[GOS]. Results : Those patients who died within two weeks [after head injury] had a significantly higher serum S-100B value than those who survived [median, 9.64ug/L versus 2.91ug/L]. Seven [78%] of the nine patients who died had a maximum S-100B value of 2ug/L or higher, while three [25%] of the twelve surviving patients showed a maximum S-100B protein value of more than 2ug/L [P<005]. Conclusion : These results indicate that S-100B protein appears to be the most reliable index for estimating the extent of brain damage.