• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.167-171
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• 2006

In this study, for the establishment of the performance evaluation methods of repair material and method for reinforced concrete structure and the quality control standards of durability recovery method, the quantitative exposure data by exposure experiment under the coastal and normal atmosphere environment is accumulated and analyzed. Investigating and evaluating the result of exposure experiment during 30 months of exposure age under the coastal and normal atmosphere environment, carbonation depth and chlorideion penetration depth very little penetrated than cover depth. It seems reasonable to conclude that main cause of corrosion of reinforcing bar are inner chloride-ion and macro cell from the result of corrosion area and corrosion velocity. Accordingly, it is considered that fundamental data on the performance evaluation and quality control standards of repair material and method could be presented through continuous exposure test in the future.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2827-2832
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• 2016

Purpose: To estimate the number of deaths attributable to second hand smoking (SHS) in Morocco in 2012. Materials and Methods: prevalence based study focusing on mortality from ischaemic heart disease (IHD) and lung cancer among non-smokers aged 35 and over. Prevalence of SHS among never smokers was gathered from a national cross sectional survey on tobacco and population attributable risk (PAR) was calculated by applying PARs to mortality. The analyses were stratified by sex, age and area of exposure. Results: Rates for exposure to SHS among men aged 35-64 years ranged from 20.0% at home to 57.4% at work. Among non-smoking Moroccans aged 35 and over, 233 (IC: 147 - 246) deaths were attributable to exposure to SHS; 156 (IC: 100 - 221) in women and 77 (IC: 44 -125) in men. A total of 173 (122 - 222) deaths were estimated to have been caused by exposure only at home, 34 (9 - 76) by exposure only at the work place and 26 (15 - 58) by exposure both at home and work places. Exposure to SHS could be responsible for 182 (128 - 237) deaths from IHD and 51 (19 - 109) from lung cancer. Conclusions: These data confirm that SHS needs urgent attention in Morocco.

• Journal of Radiation Protection and Research
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• v.46 no.1
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• pp.1-7
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• 2021

Background: The use of computed tomography (CT) device has increased in the past few decades in Japan. Dose optimization is strongly required in pediatric CT examinations, since there is concern that an unreasonably excessive medical radiation exposure might increase the risk of brain cancer and leukemia. To accelerate the process of dose optimization, continual assessment of the dose levels in actual hospitals and medical facilities is necessary. This study presents organ dose estimation using pediatric cerebral CT scans in the Kyushu region, Japan in 2012 and the web-based calculator, WAZA-ARI (https://waza-ari.nirs.qst.go.jp). Materials and Methods: We collected actual patient information and CT scan parameters from hospitals and medical facilities with more than 200 beds that perform pediatric CT in the Kyushu region, Japan through a questionnaire survey. To estimate the actual organ dose (brain dose, bone marrow dose, thyroid dose, lens dose), we divided the pediatric population into five age groups (0, 1, 5, 10, 15) based on body size, and inputted CT scan parameters into WAZA-ARI. Results and Discussion: Organ doses for each age group were obtained using WAZA-ARI. The brain dose, thyroid dose, and lens dose were the highest in the Age 0 group among the age groups, and the bone marrow and thyroid doses tended to decrease with increasing age groups. All organ doses showed differences among facilities, and this tendency was remarkable in the young group, especially in the Age 0 group. This study confirmed a difference of more than 10-fold in organ doses depending on the facility and CT scan parameters, even when the same CT device was used in the same age group. Conclusion: This study indicated that organ doses varied widely by age group, and also suggested that CT scan parameters are not optimized for children in some hospitals and medical facilities.

• Journal of agricultural medicine and community health
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• v.20 no.2
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• pp.187-195
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• 1995

Hwamunsok(mat with flower design) is a special product of Kanghwa, which is made up of cyperus exaltatus. According to Allergy, cyperus exaltatus is one of the inhalant allergens and provokes respiratory symptoms and signs. There have been few reports about respiratory allergic disease or contact dermatitis occurring in farmers who cultivate the cyperus exaltatus or manufacture Hwamunsok with it. We studied the relationship between allergic symptoms and exposure to cyperus exaltatus. First, we questioned 141 voluntaries living in Kangwha on the symptoms of contact dermatitis, allergic rhinitis and bronchial asthma. Secondly, open tests with cyperus exaltatus were done to permitted 73 voluntaries. Patch tests with the European standard series(23 antigens) were only done to exposure 49 subjects to cyperus exaltatus. The results were as follows : 1. As the manifestation rate of allergic symptoms by age, its of 60 years old over in male showed 333 per 1,000 persons. Its of 50 years old in female showed 412 per 1,000 persons. Those age groups in both genders exhibited the highest manifestation of allergic symptoms than all other age groups. Also, if age and sex were adjusted with the rural population of Kanghwagun('93 base population), the manifestation rate of allergic symptoms in male showed 283 per 1,000 persons. Its in female and totals of study populations showed which is each 206 and 234 per 1,000 persons. Specially, it showed that statistics significantly(p=0.002), exposured subjects by cultivation of cyperus exaltatus & manufacture of Hwamunsok have experienced symptoms of contact dermatitis more frequently than unexposured subjects. Secondly, it tested statistics significantly that the risk factor as manifestation of allergic symptoms was the exposure of cyperus exaltatus's allergen(p=0.024). The manifestation risk of allergic symptoms in exposure groups was 3.73 times higher than unexposured subjects. Thirdly, positive reactions in open tests with cyperus exaltatus were higher in exposured subjects than non-exposured subjects. After 72 and 96 hours, positive reactions in open tests were all 10 subjects(20.4%). Also, after 1 week, positive reactions were 8 subjects(16.4%). In conclusion there is a close relationship between contact dermatitis and exposure to cyperus exaltatus while cultivating it and manufacturing Hwamunsok. Therefore, various studies should be continued and a health education program undertaken on contact dermatitis with those who were be engaging in Hwamunsok's manufacture.

• Journal of Life Science
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• v.23 no.2
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• pp.157-166
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• 2013

This study aimed to investigate whether nociceptin contributes to the alterations in cerebral blood flow (CBF) regulation following postnatal exposure to ethanol in Sprague-Dawley rats. Animals received ethanol twice a day, 2 hr apart, on postnatal 6, 7 and 8 days. The changes in regional CBF (rCBF) in response to the changes in mean arterial blood pressure were determined at 4-, 8-, and 12-week of age by laser-Doppler flowmetry. Hypotension was induced by the gradual withdrawal of blood from arterial catheter, and the reversal of blood pressure was produced by the reinfusion of blood. Expression of nociceptin-like immunoreactivity was determined in dura mater and cerebral cortex using immunohistochemistry. Postnatal exposure to ethanol almost abolished the autoregulation of rCBF in all age groups. Pretreatment with nociceptin but not with [$Nphe^1$]nociceptin(1-13)$NH_2$, a selective competitive nociceptin receptor antagonist, 5 min prior to ethanol administration preserved the autoregulation of rCBF in all age groups. Postnatal exposure to ethanol markedly increased the expressions of nociceptin-like immunoreactivity in the dura mater and cerebral cortex, both of which were significantly inhibited by pretreatment with 7-nitroindazole monosodium salt as well as aminoguanidine 5 min prior to ethanol administration in all age groups. The values of arterial blood gas analysis were not significantly different from the basal levels in all groups. These results suggest that nociceptin deeply contributes to the compensatory mechanisms for the nitric oxide-dependent alterations in CBF autoregulation following postnatal exposure to ethanol.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.73-83
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• 2005

Higher methylmercury (MeHg) accumulation and susceptibility to toxicity in the fetus than in the mother at parturition is well known. However, the difference in MeHg exposure to fetus and offspring throughout gestation and suckling is not well established. In the human, the effects of MeHg exposure on pregnant and breast-feeding women remain an important issue for elucidation, especially those of continuous uptake in high-fish-consumption populations. The purpose of this paper was to evaluate the difference in MeHg exposure to fetus and offspring throughout gestation and lactation using our recent animal and human studies data. In the animal study, adult female rats were given a diet containing 5 ${\mu}$g/g Hg (as MeHg) for 8 weeks. Then they were mated and subsequently given the same diet throughout gestation and suckling. On embryonic days 18, 20, 22 and at parturition, the concentrations of Hg in the brains of fetus were approximately 1.5-2.0 times higher than those in the mothers. However, during the suckling period Hg concentrations in the brain rapidly declined to about 1/10 of that during late pregnancy. Hg concentrations in blood also decreased rapidly after birth. In human study, Hg concentrations in red blood cells (RBCs-Hg) in 16 pairs of maternal and umbilical cord blood samples were compared at birth and 3 months of age after parturition. RBCs-Hg concentration in the umbilical cords was about 1.6 times higher than those in the mothers at parturition. However, all the infants showed declines in Hg concentrations throughout the breast-feeding period. The Hg concentration in RBCs-Hg at 3 months of age was about half that at birth. Both the animal and human studies indicated that MeHg exposure to the fetus might be especially high but it dramatically decreases during the suckling period. Therefore, close attention should be paid to the gestation rather than the breast-feeding period to avoid the risk of MeHg to human infants.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2783-2787
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• 2013

To assess the risk of cancer incidence after medical radiation exposure for coronary artery disease (CAD), a retrospective cohort study was conducted based on Taiwan's National Health Insurance Research Database (NHIRD). Patients with CAD were identified according to the International Classification of Diseases code, 9th Revision, Clinical Modification (ICD-9-CM), and their records of medical radiation procedures were collected from 1997 to 2010. A total of 18,697 subjects with radiation exposure from cardiac imaging or therapeutic procedures for CAD were enrolled, and 19,109 subjects receiving cardiac diagnostic procedures without radiation were adopted as the control group. The distributions of age and gender were similar between the two populations. Cancer risks were evaluated by age-adjusted incidence rate ratio (aIRR) and association with cumulative exposure were further evaluated with relative risks by Poisson regression analysis. A total of 954 and 885 subjects with various types of cancers in both cohorts after following up for over 10 years were found, with incidences of 409.8 and 388.0 per 100,000 person-years, respectively. The risk of breast cancer (aIRR=1.85, 95% confidence interval: 1.14-3.00) was significantly elevated in the exposed female subjects, but no significant cancer risk was found in the exposed males. In addition, cancer risks of the breast and lung were increased with the exposure level. The study suggests that radiation exposure from cardiac imaging or therapeutic procedures for CAD may be associated with the increased risk of breast and lung cancers in CAD patients.

• Journal of Nutrition and Health
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• v.39 no.6
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• pp.539-548
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• 2006

In recent years a concern of excessive intakes of vitamins and minerals from various sources is increasing, since there has been a marked increase in production and consumption of vitamin and mineral supplements and fortified foods. The purpose of this study was to assess the maximum exposure of vitamins and minerals from various sources including diet, fortified foods, and health functional foods among Koreans. As a result, the highest exposure group of most vitamins and minerals from diet was adults (30 - 49 years of age) according to 2001 Korean National Nutrition and Health Survey Report. Maximum dietary intakes of vitamin A, $B_1,\;B_2$, C, nicotinamide, calcium, phosphorus and iron were 0.5 - 7 times of the RDA for Koreans, 7th ed. Maximum intakes of vitamins and minerals from fortified foods by adults (20 - 59 years of age) were 8 - 760% of the Korean RDA. In addition, maximum exposure of vitamins and minerals from vitamin mineral health functional foods by middle aged people was 35 - 140% of the upper limits (UL: DRI for Koreans). As a consequence, maximum combined intakes of vitamin $B_6$, vitamin C, calcium, iron and zinc from the above sources including diet, fortified foods and vitamin mineral health functional foods were greater than the UL. These results would be applied for determining the safe upper limits of vitamin and mineral of health functional foods.

• Toxicological Research
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• v.33 no.2
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• pp.157-164
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• 2017

This study was to evaluate the age-dependent effects of caffeine exposure on the long bones and reproductive organs using male rats. A total of 15 immature male rats and 15 young adult male rats were allocated randomly to three groups: a control group and two groups fed caffeine with 120 and 180 mg/kg/day for 4 weeks. Exposure to caffeine at either dose significantly reduced body weight gain; a proportional reduction in muscle and fat mass in immature animals, whereas a selective reduction in fat mass with relatively preserved muscle mass in young adult animals. The long bones of immature rats exposed to caffeine were significantly shorter and lighter than those of control animals along with decreased bone minerals. However, there was no difference in the length or weight of the long bones in young adult rats exposed to caffeine. Exposure to caffeine reduced the size and absolute weight of the testes significantly in immature animals in comparison to control animals, but not in young adult animals exposed to caffeine. In contrast, the adrenal glands were significantly heavier in caffeine-fed young adult rats in comparison to control animals, but not in caffeine-fed immature rats. Our results clearly show that the negative effects of caffeine on the long bones and testes in rats are different according to the age of the rat at the time of exposure, and might therefore be caused by changes to organ sensitivity and metabolic rate at different developmental stages. Although the long bones and testes are more susceptible to caffeine during puberty, caffeine has negative effects on body fat, bone minerals and the adrenal glands when exposure occurs during young adulthood. There is a need, therefore, to educate the public the potential dangers of caffeine consumption during puberty and young adulthood.

• 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.