• 한국산업보건학회지
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• 제32권2호
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• pp.146-152
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• 2022

Objectives: The purpose of this study is to confirm whether there is a factor to affect the evaluation of fit test of a 2nd class half masks using a OPC test method. Methods: Total 34 adults including Males and Females were tested using OPC-based fit testing equipment while wearing a 2nd class half filtered mask. Results: 1. The result of measuring face dimensions using different tools such as a 3D scanner and digital calipers revealed that the variation of lip width was not statistically significant because there was only a difference of about 4 mm. However, it showed that a difference in face length was statistically significant enough with 10 mm(p<0.000). 2. The fit factor for each exercise stage according to gender was the highest at 124.54(p<0.001) in Step 3, and the fit factor was the lowest at 73.75 in Step 1. 3. In the evaluation of the degree of fit factor according to gender, female passed 67.44%, which was higher than the value in male(p<0.038). 4. The acceptance rate of the group having a face length of shorter than 110 mm was 91.67%. On the other hand, the acceptance rate of the group with a face length of longer than 110 mm was 47.27%(p<0.000). 5. The fit test was possible because the fit factor with 2nd class half masks corresponding to FFP1(Filtering Face Piece 1) was passed 55% or more. Conclusions: The test results showed that using a 2nd class half filtered mask, it is important to wear a properly designed mask so that face size does not affect the fit factor.

• 한국초등과학교육학회지:초등과학교육
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• 제42권4호
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• pp.618-629
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• 2023

우리 사회는 다양성이 점차 커져가고 있으나 초등 과학 교과서를 인종이나 장애의 측면에 분석한 연구는 거의 없다. 이에 본 연구에서는 초등 과학 교과서에 제시된 인물 삽화의 다양성을 다문화와 장애의 측면에서 분석하였다. 분석 대상은 2015 개정 교육과정 검정 초등 과학 교과서 중 3학년 1, 2학기 교과서 7종 총 14책이었다. 연구 결과는 다음과 같다. 첫째, 초등 과학 교과서에 제시된 인물 삽화의 인종을 분석한 결과, 3학년 과학 교과서에 제시된 인물 삽화 중 다문화 인물 삽화는 8.2%로 실제 국내 거주 외국인 비율보다 높게 나타났다. 그리고 인종별로는 백인 삽화가 가장 많고 아시아계 외국인 삽화가 가장 적어, 아시아계 외국인이 많은 우리나라 상황과는 다른 분포로 제시되고 있었다. 출판사별로는 이 분포에 상당한 차이가 있었다. 둘째, 다문화 인물 삽화의 성별 분포는 남성이 59.0%, 여성이 41.0%로 차이가 있었으며, 일부 출판사는 남성 다문화 인물이 80%에 이르는 등 출판사에 따라 성별 편차가 상당히 크게 나타났다. 셋째, 삽화의 기능 측면에서 한국인과 다문화 인물 삽화의 분포는 설명적 기능의 삽화가 가장 많고, 다음으로 예시적 삽화, 장식적 삽화, 보충적 기능의 삽화 순으로 유사하게 나타났다. 마지막으로 초등 과학 교과서의 인물 삽화를 장애 다양성 측면에서 분석한 결과, 장애인의 비율은 2.0%로, 국내 장애인 비율보다 적은 비율이었다. 인종과 장애의 측면에서 우리나라의 상황과 다양성을 고려할 필요성에 대해 논의하였다.

• Journal of Photoscience
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• 제9권2호
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• pp.154-157
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• 2002

Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

• Tuberculosis and Respiratory Diseases
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• 제67권1호
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• pp.8-13
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• 2009

Background: The insulin receptor substrate-1 (IRS-1) is the primary docking molecule for the insulin-like growth factor I receptor (IGF-IR), and is required for activation of the phosphatidylinositol 3'-kinase (PI3K) pathway. IRS-1 activation of the (PI3K) pathway regulates IGF-mediated survival, enhancement of cellular motility and apoptosis. Therefore, we attempted to ascertain whether IRS-1 genetic variations affect an individual's risk for non-small cell lung cancer (NSCLC). Methods: Two-hundred and eighteen subjects, either diagnosed with NSCLC or control subjects, were matched by age, gender and smoking status. Genomic DNA from each subject was amplified by PCR and analyzed according to the restriction fragment length polymorphism (RFLP) profile to detect the IRS-1 G972R polymorphism. Results: The frequencies of each polymorphic variation, in the control population, were as follows: GG=103 (94.5%) and GR=6 (5.5%); for the NSCLC subjects, the genotypic frequencies were as follows: GG=106 (97.2%) and GR=3 (2.8%). We could not demonstrate statistically significant differences in the genotypic distribution between the NSCLC and the control subjects (p=0.499, Fisher's Exact test). The relative risk of NSCLC, associated with the IRS-1 G972R polymorphic variation, was 1.028 (95% CI; 0.63~9.90). In addition, we found no differences between polymorphic variants with regard to the histological subtype of NSCLC. Conclusion: We did not observe any noteworthy differences in the frequency of the IRS-1 G972R polymorphism in NSCLC patients, compared to control subjects. These results suggest suggesting that, in our study population, the IRS-1 G972R polymorphism does may not appear to be associated with an increased risk of NSCLC.

• 한국환경보건학회지
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• 제47권6호
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• pp.521-529
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• 2021

Background: The coronavirus disease (COVID-19) has caused changes in human activity, and these changes may possibly increase or decrease exposure to fine dust (PM_2.5). Therefore, it is necessary to evaluate the exposure to PM_2.5 in relation to the outbreak of COVID-19. Objectives: The purpose of this study was to compare and evaluate the exposure to PM_2.5 concentrations by the variation of dynamic populations before and after the outbreak of COVID-19. Methods: This study evaluated exposure to PM_2.5 concentrations by changes in the dynamic population distribution in Guro-gu, Seoul, before and after the outbreak of COVID-19 between Jan and Feb, 2020. Gurogu was divided into 2,204 scale standard grids of 100 m×100 m. Hourly PM_2.5 concentrations were modeled by the inverse distance weight method using 24 sensor-based air monitoring instruments. Hourly dynamic population distribution was evaluated according to gender and age using mobile phone network data and time-activity patterns. Results: Compared to before, the population exposure to PM_2.5 decreased after the outbreak of COVID-19. The concentration of PM_2.5 after the outbreak of COVID-19 decreased by about 41% on average. The variation of dynamic population before and after the outbreak of COVID-19 decreased by about 18% on average. Conclusions: Comparing before and after the outbreak of COVID-19, the population exposures to PM_2.5 decreased by about 40%. This can be explained to suggest that changes in people's activity patterns due to the outbreak of COVID-19 resulted in a decrease in exposure to PM_2.5.

• 농촌의학ㆍ지역보건
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• 제33권3호
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• pp.346-355
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• 2008

- Abstract - Objectives: The purpose of this study is to describe and analyze the characteristics of which laypersons want the cardiopulmonary resuscitation(CPR) education. Methods: Based on a health survey(ｎ=913) of 5 remote places in Korea, tests of the differences between the group that wants the CPR education(ｎ=416) and the group that doesn't(ｎ=497), and a logistic regression analysis of two groups was performed on socio-economic status and health-medical conditions. Results: Even the participation rate of the CPR education in Korea is only 5.8%, which is extremely lower than other developed countries, there are statistically significant differences between the group that wants the CPR and the group that doesn't on gender(ｐ=0.001), age(ｐ=0.000), education level(ｐ=0.000), economic status(ｐ=0.007), and CPR education taken(ｐ=0.000), and health status(ｐ=0.042). Furthermore, age(OR=1.599, ｐ=0.002), age(OR=0.964, ｐ=0.000), economic status(OR=0.804, ｐ=0.028), and CPR education taken(OR=2.072, ｐ=0.026) are statistically significant factors on the willingness to receive the CPR education. Conclusions: This study indicates that there is considerable variation in socio-economic status and health-medical conditions associated with the willingness to receive the CPR education. In remote places. certain subgroups of laypersons such as high-risk patients and family members need targeted outreach programs in CPR education.

• Imaging Science in Dentistry
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• 제44권3호
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• pp.229-236
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• 2014

Purpose: To investigate the prevalence of bifid and trifid mandibular canals using cone-beam computed tomography (CBCT) images, and to measure their length, diameter, and angle. Materials and Methods: CBCT images of 500 patients, involving 755 hemi-mandibles, were used for this study. The presence and type of bifid mandibular canal was evaluated according to a modified classification of Naitoh et al. Prevalence rates were determined according to age group, gender, and type. Further, their diameter, length, and angles were measured using PACSPLUS Viewer and ImageJ 1.46r. Statistical analysis with chi-squared and analysis of variance (ANOVA) tests was performed. Results: Bifid and trifid mandibular canals were found in 22.6% of the 500 patients and 16.2% of the 755 sides. There was no significant difference between genders and among age groups. The retromolar canal type accounted for 71.3% of the identified canals; the dental canal type, 18.8%; the forward canal type, 4.1%; and the trifid canal type, 5.8%. Interestingly, seven cases of the trifid canal type, which has been rarely reported, were observed. The mean diameter of the bifid and trifid mandibular canals was 2.2 mm and that of the main mandibular canal was 4.3 mm. Their mean length was 16.9 mm; the mean superior angle was $149.2^{\circ}$, and the mean inferior angle was $37.7^{\circ}$. Conclusion: Bifid and trifid mandibular canals in the Korean population were observed at a relatively high rate through a CBCT evaluation, and the most common type was the retromolar canal. CBCT is suggested for a detailed evaluation of bifid and trifid mandibular canals before mandibular surgery.

• Nutrition Research and Practice
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• 제5권4호
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• pp.357-364
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• 2011

Selenium is an antioxidant trace element linked to cardiovascular disease and cancer. Although diet is a major source, relatively little else is known about independent determinants of selenium levels in free-living humans. In this study, we aimed to investigate the independent demographic. lifestyle, and dietary determinants of selenium levels in 1,997 men and 1,905 women in two large prospective U.S. cohorts. Toenail selenium levels were quantified using neutron activation analysis. Diet, geographic residence, demographic, and environmental factors were assessed by validated self-administered questionnaires. Multivariate generalized linear models were conducted to assess the independent relations of these factors with toenail selenium levels, correcting for measurement error in the diet. In multi variable-adjusted analyses, independent predictors of higher selenium were male gender (6.3% higher levels); living in West and Northern-Midwest U.S. regions (8.9% and 7.4% higher than Southern-Midwest regions, respectively); consumption of beef and bread products (between 0.7 - 2.5% higher per daily serving); and selenium supplement use (6.9% higher than non-users); whereas cigarette smoking (5-10% lower than never smokers), older age (0.6% lower per 5 years), and consumption of eggs, white rice, dairy products, coffee, and alcohol (between 0.1 to 2.0% lower per daily serving) were associated with lower selenium. Multiple dietary and non-dietary factors independently predicted selenium levels, suggesting that both consumption and non-dietary processes (e.g.. related to oxidant status) may affect levels. Significant geographic variation in selenium levels exists in the US.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.693-698
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• 2012

Breast cancer is the most frequent cancer of women worldwide, with considerable geographic and racial/ethnic variation. Data are generally derived from population based cancer registries in the developed countries but hospital data are the most reliable source in the developing countries. Ten years data from 1st Jan 2000 to 31st Dec 2009 of a cancer hospital in Pakistan were here analyzed by descriptive statistics to evaluate the clinicopathologic profile of local breast cancer patients. Among 28,740 cancer patients, 6,718 were registered as breast cancer. The female to male ratio was 100:2. Breast cancer accounted for 23% of all and 41% of female cancers. Some 46% were residents of Lahore, with a mean age of $47{\pm}12$ years. Less than 1% were at Stage 0 and 10%, 32%, 35% and 23% were at Stage I, II, III and IV respectively. Histopathology was unknown in 4% while 91%, 2% and 1% had invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC) and mucinous carcinoma respectively. Rare carcinomas accounted for the rest. Tumor grade 1, 2 and 3 was 11%, 55% and 34% among the known. Profile of breast cancer patients in Pakistan follows a pattern similar to that of other developing countries with earlier peak age and advanced disease stage at presentation. The male breast cancer accounts for higher proportion in the local population. Local women have higher frequency of IDC and lower frequency of ILC and DCIS, owing probably to a different risk profile. Use of hospital information systems and establishment of population based cancer registry is required to have accurate and detailed local data. Promotion of breast health awareness and better health care system is required to decrease the burden of advanced disease.

• 한국환경보건학회지
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• 제40권1호
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• pp.17-26
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• 2014

Background: Despite children's unique characteristics that distinguish them from adults, relatively few attempts have been made to measure exposure factors for characterization of children's exposure to hazardous chemicals in child-specific products (CSP). This study was conducted to establish the child-specific exposure factors for exposure and risk assessment of hazardous substances in CSP. Methods: We investigated the exposure factors (e.g., time use of child-products, time and frequency of object-to-body contact, time and frequency of object-to-mouth contact) influencing children's exposure to CSP (e.g., toys, playmats, oil pastels, etc.) in 650 children through a parent-completed questionnaire using a web-based survey. Participants were recruited in five age groups, <1, 1-2, 2-3, 3-6, and 6-12 years of age. Results: The child-specific exposure factors were presented as the mean, median, $95^{th}$ percentile, minimum, and maximum values. Time activity for play mats was the longest among CSP and infants spent more time on them than did elder age groups (189.3-224.7 min/day for <1-2 years vs. 91.2 min/day for 6-12 years). It is apparent that time and frequency of toy block- and plastic toy-to-mouth contact significantly decreased as a function of age. When the variation of CSP use patterns was compared by gender, the only variable that was statistically different between genders was time activity in child-products exposure space. Conclusion: We believe the five child-specific exposure factors suggested in the present study will be valuable for reducing uncertainty in the estimation of chemical exposure during risk assessment of CSP and furthermore, in the appropriate regulations to protect children's health.