• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.102-108
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• 2008

Many alternative biocidal additives were applied to antifouling paint to replace TBT, and Sea-Nine 211 is one of alternating organic booster compounds used in antifouling paint. In this study, extent of Sea-Nine 211 toxicity on marine benthic bivalve is evaluated. Sea-Nine 211 was injected to surf clam, Pseudocardium sachalinensis, that inhabitate northern part of Gangwon Province, Korea. Survival rate of the clam and xenobiotics metabolizing enzyme activities in digestive gland were measured during 4 day-exposure period. The results were compared with those of TBT exposed clam. There were no mortality of clam in the solvent (DMSO) control group and the three Sea-Nine 211 exposure groups (5, 25, 50 mg kg$^{-1}$ body weight), while the clam exposed to 1, 2 and 5 mg kg$^{-1}$ TBT chloride (TBTC) demonstrated 70, 30 and 0% survival rate, respectively. The Sea-Nine 211 exposure group showed a tendency of cytochrome P450 (CYP) induction according to the exposure duration, on the other hand, CYP content was decreased in the TBT exposure group. NADPH cytochrome P450 reductase activity slightly increase according to the exposure duration in the Sea-Nine 211 exposure group, while TBTC inhibit its activity as CYP content. Moreover, there was no significant change of NADH cytochrome b5 reductate activity in the clam epxosed to Sea-Nine 211. In the TBTC exposure group, its activity increased in early exposure period and then significantly decreased the rest of exposure period. All the results indicate that Sea-Nine 211 demonstrated a tendency to induce CYP level, while TBTC inhibits the CYP level, NADPH cytochrome P450 reductase and NADH cytochrome b5 reductase activities.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.72-78
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• 2009

Exposure to HDI(hexamethylene di-isocyanate) commonly used in vehicle crash repair workshops remains a leading cause of occupational asthma. Although skin and eye contamination are considered as absorption routes, there are no occupational exposure standards for skin and ocular exposure. This is the reason why there are more empirical data should be provided. Therefore this study was to determine contamination levels of HDI on the skin, eyes, work surfaces, respirators and eye protectors. There was evidence of contamination on a variety of work surfaces, for example, door handles, bench top and spray gun, etc. A high proportion(47~80%) of skin wipe samples from neck, forehead, back hand, palm and wrist was positive for HDI contamination, even though spray time was relatively brief. The contamination levels from spraying inside spray booth were generally higher than outside booth due to poor work practices and inappropriate personal protective use like safety gloves. Apprentices had higher exposure levels than the qualified painters, likely due to lack of the recognition of safety and hygiene. The extent of contamination inside the PPE might provide an indication of the potential for respiratory & skin exposure and ocular exposure. Eye fluid samples from 4 out of 14 workers had the positive detection of HDI contamination, due to poor work practices like no or inappropriate eye protection. Considering the potential for dermal & ocular exposure to contribute to possible health symptoms including respiratory sensitization, the empirical data point to a need for improving work practices and appropriate PPE selection, use and maintenance.

• Archives of Reconstructive Microsurgery
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• v.6 no.1
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• pp.87-95
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• 1997

Traumatic injury to the hand often leads to soft tissue defects with exposed tendons, bones, or joints. Though many new flap have been introduced, the choice of flap that would be best for the patient depends on such factors as the site, size, and degree of wounds. Additionally the selected surgical method should be yielded cosmetic and functional superiority by the one-staged reconstruction. In our experience, small to medium sized soft tissue defect with bone and tendon exposure of hand can be resurfaced with an arterialized venous free flap from the volar aspect of distal forearm. Wide and deep defects of the hand can be covered with a sensory cutaneous free flap such as the medial plantar free flap, dorsalis pedis free flap, and radial forearm free flap. Specialized flap such as wrap-around flap, toe-to-finger transfer, onychocutaneous free flap can be used for the recontruction of defect on the thumb and finger. Based on the above considerations and our clinical experience of 60 free flap cases of the hand, the various methods for the proper repair of soft tissue defects of the hand are described. And we obtained satisfactory functional and cosmetic results with 95% success rate of free flap.

• Journal of the Korean Home Economics Association
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• v.42 no.11
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• pp.137-150
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• 2004

The purpose of this study was to examine the effect of clothing color and exposure on stereotype formation of female appearance. The subjects for the research survey were 418 male and female university students in Taejon, Korea. The measuring instruments were a self-administered questionnaire and six written scripts which described a woman wearing clothing manipulated by clothing color and exposure variables. The collected data were analyzed using content analysis, T-test, crosstabs analysis, ANOVA, and Duncan's multiple range test. The results of this study were as follows. First, three dimensions (global image, appearance inference, and appearance evaluation) emerged from the subject responses. Clothing exposure had the greatest impact upon the stereotype formation of female appearance. The woman wearing exposed clothing was rated as 'sexy', 'confident', and 'glamorous' whereas the same woman wearing unexposed clothing was rated as 'slim', 'humdrum', 'ladylike', and 'neat'. Second, the gender of the subject played a role in forming stereotypes of women's appearance. The male subjects rated the woman wearing exposed clothing as 'sexy' and 'glamorous' whereas the 1em81e subjects rated the same woman as 'slim' and 'pretty'. Third, the male subjects evaluated the woman wearing expend clothing in much more negative terms than the female subjects did, indicating that men tended to use 'modesty' to evaluate the woman whereas women tended to use 'fashion trend' in addition to 'modesty' as the important criteria when assessing women dressed in exposed clothing. Fourth, the subjects judged the woman wearing exposed clothing to be an entertainer or prostitute in her early 20s. On the other hand, the subjects judged the woman wearing unexposed clothing to be either a university student or a professional business women in her mid 20s.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.43-57
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• 1996

To characterize worker's exposure to glass fibers, to find the correlation between airborne total dust concentrations and fiber concentrations and to recommend an appropriate evaluation method for worker's exposure to fibrous dusts in glass wool industry, we carried out this study. Average respirable fiber levels at five factories were 0.013-0.056 f/cc, and fairly below the OSHA PEL, 1 f/cc. A factory showed the lowest airborne fiber level, 0.013 f/cc, which was different significantly from those of other factories of which average fiber concentration was 0.046 f/cc. The cutting and grinding operations of insulation products resulted in higher airborne fiber cocentrations than any other processes(p<0.05). To characterize airborne fiber dimension, fiber length and diamter were determined using phase contrast microscope. The geometric means of airborne fiber lengths were $42-105 \mu m$. One factory had airborne fibers whose length distribution(GM = $105 \mu m$) was different from those of other factories(GM = $42-50 \mu m$). The percentages of respirable fibers less thinner than 3 gm were 38.9-90.9% at four factories, and two factories of them had the higher percentages than others. The findings explain for variation of airborne fiber diameters between factories. On the other hand, between the processes were the difference of fiber-length distributions observed. The cutting and grinding operations showed shorter fiber-length distributions than the fiber forming one. However, fiber-diameter distributions or respirable fiber contents were similar in all processes. The airborne fiber concentrations and the dust concentrations had relatively weak correlation(r=0.25), thus number of fibers couldn't be expected reliably from dust amount. Fiber count is appropriate for assessing accurate exposures and health effects caused by fibrous dusts including glass fibers. Ministry of Labor have established occupational exposure limit to glass fibers as nuisiance dust, but should establish it on the basis of respirable fiber concentration to provide adequate protection for worker's health

• Journal of Preventive Medicine and Public Health
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• v.37 no.4
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• pp.291-299
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• 2004

As there have been growing concerns about the adverse effects of air pollution on birth outcome, studies for this area has been carried out in different populations and sites. We reviewed the epidemiologic studies that evaluated the effects of air pollution on birth outcome such as low birth weight and preterm births. We identified the air pollution exposure during pregnancy was related with low birth weight and preterm birth, although there are differences among studies for the critical period of vulnerability. The biological mechanisms whereby air pollution might influence health of fetus are not clearly established. The exposure to carbon monoxide(CO) during pregnancy could increase fetal carboxyhemoglobin and result in tissue hypoxia. On the other hand, ambient particles less than $10{\mu}m$ in aerodynamic diameter($PM_{10}$) could lead to inflammation and increase blood viscosity. Controlling for potential confounders and valid assessment of exposure are the methodological issues remained in these epidemiologic studies. In the future, more studies are needed to investigate the effect of air pollution on preterm birth or stillbirths, considering the various exposure period and the biological mechanism.

• Journal of radiological science and technology
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• v.38 no.4
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• pp.477-482
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• 2015

Workers in nuclear medicine have performed various tasks such as production, distribution, preparation and injection of radioisotope. This process could cause high radiation exposure to wokers' hand. The purpose of this study was to investigate shielding effect for r-rays of 140 and 511 keV by using Monte-carlo simulation. As a result, it was effective, regardless of lead thickness for radiation shielding in 140 keV r-ray. However, it was effective in shielding material with thickness of more than only 1.1 mm in 511keV r-ray. And also it doesn't effective in less than 1.1 mm due to secondary scatter ray and exposure dose was rather increased. Consequently, energy of radionuclide and thickness of shielding materials should be considered to reduce radiation exposure.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.1
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• pp.113-124
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• 1990

For the study of the influence of kilovoltage and exposure time on radiographic density and contrast, we measured radiographic density of aluminum step wedge which composed of contiguous 8 steps wedges of 2-16㎜ thickness with densitometer. Aluminum step wedge was radiographed on Kodak ultraspeed DF-58 and Ektaspeed EP-21 film with range of 60-90 kVp and 5-60 impulse and subject contrast of aluminum step wedge with constant radiographic density and image contrast percentage without radiographic density was evaluated. Then we evaluated the film quality of teeth and their surrounding structure according to the change of kVp and exposure time by score rating method. The obtained results were as follows: 1. Radiographic density was related to the change of kilovoltage, especially in increased exposure time. 2. With constant radiographic density, subject contrast of thin aluminum step wedges was greater in low kilovolt age than high kilovoltage, but kilovolt age had not great influence on subject contrast of thick aluminum step wedge. On the other hand, radiographic density difference between 2mm and 16mm aluminum step wedge was decreased according to in- creasing kilovoltage. 3. Without constant radiographic density, image contrast percentage was decreased with increasing kilovoltage, but was not related with the change of exposure time. 4. Radiographic contrast of teeth and their surrounding structure which was taken with the range of 60-90 kVp and 6-30 impulse had not great influence on film quality.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.426-438
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• 2020

This study aimed to identify the components of the nurses' exposure experiences and clarify the semantic structure of nurses by analyzing the participants' experiences of exposure to radiation. The participants in this study were nine nurses who worked for at least six months in the operating room of a City General Hospital. The data were collected using in-depth interviews and analyzed using the phenomenological method by Giorgi's (2004). As a result, six components were derived: "worrying about the disease by repeated radiation exposures", "exhausting physically and mentally," "trying to protect themselves against radiation exposure", "feeling of internal confusion and conflict", "demanding improvement of work environment", and "accepting and adapting to reality". In conclusion, nurses participating in radiation exposure surgery are concerned about the possibility of disease, experience physical and mental fatigue, and then consider changing their occupation. On the other hand, they try to accept and adapt to reality by considering the possibility of a job change or trying to protect themselves from the harsh environment. To develop a radiologically safe environment, systematic and effective resolutions must be secured at the organizational level.

• Journal of Radiation Protection and Research
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• v.13 no.2
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• pp.29-40
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• 1988

A spectrum-exposure rate conversion operator G(E) for a portable HPGe detector used for field environmental radiation survey was theoretically developed on the basis of a space distribution function of gamma flux emitted from a disk source and an areal efficiency of the detector. The radiation exposure rates measured using this G(E) and the portable HPGe. detector connected to a portable multichannel analyzer were compared with those measured by a 3' ${\phi}\;{\times}$3' NaI(Tl) scintillation detector with the reported G(E) and a pressurized ionization chamber. A comparison of the three results showed that the result obtained using the HPGe detector was lower than those determined using the NaI(Tl) detector and ionization chamber by 17% to 29%, The difference obtained is close to that reported in literature. The method developed here can be easily applicable to obtain a G(E) factor suitable to any detector for detecting the exposure rate of environmental gamma radiation, since the spectrum-exposure rate conversion operator can be calculated by a hand calculator.