• 대한의생명과학회지
• /
• 제5권2호
• /
• pp.191-200
• /
• 1999

최근 다약제 내성균주의 출현과 후천성 면역결핍증으로 인한 결핵발병률의 증가는 전세계적으로 중요한 보건문제가 되었다. 따라서 보다 빠르고 신뢰할 만한 진단법은 결핵 박멸을 위한 가장 중요한 필요조건 중의 하나일 것이다. 본 연구는 171명의 환자를 대상으로 폐결핵 진단의 전통적 방법들 (X-선, 항산성 염색, 배양)과 PCR법간의 진단적 가치와 효율성을 비교 검토하기 위해 시행하였다. 흉부 X-선 소견 및 검사 결과 그리고 다른 임상 소견들을 통해 결핵으로 확진된 예는 전체 171건의 검체 중 39예 (22.8%)였다. 이러한 확진을 근거로 할 때 각 검사별 민감도, 특이도, 효율성, 위양성률, 위음성률을 살펴보면 흉부 X-선의 경우 각각 69.2%, 87.1%, 83.0%, 12.9%, 30.8%； 항산성 염색의 경우 79.9%,95.5%,91.8%,4.6%, 20.5%； 배양의 경우 56.4%,99.2%,89.5%,0.8%,43.6%； PCR의 경우 82.1%, 96.2%, 93.0%,3.8%, 17.9%였다. PCR의 경우 가장 높은 민감도 및 효율성과 가장 낮은 위음성률을 보였다. 배양법은 가장 높은 특이도와 가장 낮은 위양성률을 보였다. 결론적으로 PCR은 결핵 진단을 위한 신속하고 효율적인 우수한 검사 방법이므로 일상적 임상 검사로의 활용가치가 매우 높다고 하겠다. 그러나 전통적인 여러 방법들 역시 임상상황에 따라 그 나름대로의 특별한 가치를 지니고 있으므로 철저한 정도관리를 통해 PCR과 병행 한다면 결핵균 검출율을 보다 높일 수 있으리라 판단된다.

• Journal of Radiation Protection and Research
• /
• 제42권1호
• /
• pp.33-41
• /
• 2017

Background: Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., $^{238}U$ and $^{226}Ra$), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$ levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Materials and Methods: Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. Results and Discussion: The concentration ratios of $^{226}Ra$ and $^{238}U$ in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was $^{40}K$, and the median $^{40}K$ activity was $8.972Bq{\cdot}g^{-1}$ and $1.496Bq{\cdot}g^{-1}$, respectively. For the $^{238}U$ series, the activity of $^{238}U$ and $^{226}Ra$ was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Conclusion: Although the activity of $^{40}K$ in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of $^{226}Ra$ and $^{238}U$ in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

• 한국산업보건학회지
• /
• 제28권1호
• /
• pp.51-60
• /
• 2018

Objectives: Currently, there is only limited knowledge regarding the hazard of low-level exposure to CMR materials in workplaces. To overcome this limitation, a reference concentration for workers($RfC_w$) from among the risk assessment tools proposed by the US EPA is widely used to set a provisional workplace exposure level(PWEL) for CMR materials for which there are no established Korea Occupational Exposure Limits(KOELs) or subjective chemicals for work environment measurements as regulated by Korea Ministry of Employment and Labor(KMOEL). A simple European calculator of derived no effect level(SECO-DNEL) as proposed by REACH can also be used in place of $RfC_w$ to set the PWEL for chemicals. This study was performed to test the acceptability of using SECO-DNEL as an alternative to $RfC_w$ when setting a PWEL for low-level exposures. Methods: The $RfC_w$ and DNEL for the five CMR materials of dinitrogen oxide, catechol, 2-phenoxy ethanol, carbitol, and carbon black were calculated using the dose-response assessments of the US EPA for $RfC_w$ and REACH guidance for SECO-DNEL, respectively. They were compared using paired t-tests to determine the statistical differences between them. Results: For the five chemicals, the $RfC_w$ were 2.53 ppm, 0.10 ppm, 1.73 ppm, 1.66 ppm, and $0.05mg/m^3$, respectively, while the SECO-DNEL were 2.01 ppm, 0.11 ppm, 1.83 ppm, 1.77 ppm, $0.14mg/m^3$, respectively. There was no statistically significant difference between $RfC_w$ and SECO-DNEL. Conclusions: This study suggests that the SECO-DNEL could be applied in place of $RfC_w$ to set a PWEL for low-level exposure to chemicals, especially CMR materials. To further ensure the reliability of SECO-DNEL as an alternative tool, more chemicals should be applied for calculation and comparison with $RfC_w$.

• Restorative Dentistry and Endodontics
• /
• 제23권1호
• /
• pp.257-268
• /
• 1998

During cleaning and shaping of narrow and curved canals, it is very difficult or nearly impossible to maintain the original canal shape. Procedural accidents such as, ledge, zipping, perforation, and instrument breakage are frequently occurred and even may lead to failure of endodontic therapy. To prevent these kinds of accidents, various instrumentation techniques and materials have been introduced. Recently some nickel titanium (NiTi) files are introduced and it is reported that These NiTi files created rounder preparations with less transportation than conventional instruments in curved canals. This study compared the change of the canal curvature and procedural accidents after instrumentation produced by stainless steel K-flexo file, and NiTi rotary files (Profile 29 and Quantec 2000). Thirty narrow and curved canals (25-45 degree) of extracted human molars were randomly divided into three groups. In group 1, canals were instrumented using a step-back and watch-winding/pull motion with K-flexo files. In group 2, canals were prepared with Profile 29. Group 3, canals were prepared with Quantec 2000 files. Before and after preparation of canals, periapical radiographs were taken and scanned. The change of canal curvature were measured using Photoshop 4.0 program and the incidence of procedural accidents were also evaluated. The results were as follows: 1. All group showed some loss of canal curvature after instrumentation. 2. Average loss of canal curvature was $6.70{\pm}5.31$ degree for group 1, $3.80{\pm}2.57$ degree for group 2, and $5.40{\pm}4.83$ degree for group 3. All group There was significant change in curvature between before and after instrumentation (p<0.05). But there was no statistical difference amoung 3 groups. 3. In group I, there were no procedural accidents, such as ledging, perforation, or instrument fracture. In group 2, two cases of ledge and one case of instrument fracture were produced Goup 3, each one case of ledge, perforation and instrument fracture were occurred. Whthin the limits of above results, It seems that NiTi rotary instrumentation is not All Mighty and if we use uncarefully, it is more dangerous to produce some procedural accidents than conventional hand files. But more studies should be taken to evaluate the exact effects of NiTi rotary instrumentations.

• 한국콘텐츠학회논문지
• /
• 제19권4호
• /
• pp.581-597
• /
• 2019

본 연구는 노인복지관 사회복지사의 긍정심리자본이 직무소진에 미치는 영향관계를 검증하고자 설계되었다. 조사대상은 서울특별시와 경기도에 소재한 노인복지관에서 노인을 직접 돌보는 사회복지사 350명을 대상으로 설문조사를 실시하였다. 회수된 설문지 중 최종 344부를 SPSS 22.0 통계프로그램을 사용하여 분석 처리하였다. 자료의 분석은 신뢰도 검사, 빈도분석, t-검증, 일원배치분산분석, 상관관계 분석, 다중회귀분석을 실시하였다. 연구결과, 긍정심리자본이 직무소진의 하위변수인 감정고갈에 통계적으로 유의미한 부(-)의 영향을 미치는 것으로 나타났고, 비인격화에 통계적으로 유의미한 부(-)의 영향을 미치는 것으로 나타났다. 긍정심리자본의 하위변수가 감정고갈과 비인격화에 미치는 영향은 낙관주의>회복력>희망>자기효능감으로 나타났다. 마지막으로 긍정심리자본이 성취감저하에 통계적으로 유의미한 부(-)의 영향을 미치는 것으로 나타났다. 긍정심리자본의 하위변수가 성취감저하에 미치는 영향은 낙관주의>희망>자기효능감>회복력으로 나타났다. 이러한 연구결과를 바탕으로 사회복지사의 직무소진을 감소시키는 요인으로 확인된 긍정심리자본 향상을 위한 제언과 연구의 한계점 및 향후 연구방향을 제시하였다.

• International Journal of Computer Science & Network Security
• /
• 제21권3호
• /
• pp.257-265
• /
• 2021

Modern methods of regulating migration processes in EU states include a wide variety of adapted, transformed under the sway of globalization tools in order to influence the movement of human capital within the European space. The main purpose of the regulatory policy on migration flows is the redistribution of professionally competent professionals between different spheres of life. Herewith, the determining factor in the effectiveness of such distribution is a rational combination of stimulating and disincentive levers of influence on the movement of citizens of different EU countries and taking into account the motives of such mobility. Modernization of migration management approaches can be a major economic, social, political and cultural progress of European countries. The purpose of the research is to conduct a detailed analysis of existing practices of migration flow management, in particular their stimulation or containment, and to outline key migration trends formed under the influence of multicomponent approaches to migration regulation, transformation of regulatory legislation and changing priorities of modern society. The research methods: statistical-analytical method; ARIS method; method of tabular, graphical and analytical modeling; comparative analysis; systematization, generalization. Results. Current pan-European methods of regulating migration processes are insufficiently adapted to the multinational socialeconomic space; consequently, there are some disparities in the distribution of migrants between EU countries, although the overall dynamics of migration is positive. Fluctuations in the population of European countries during 2000-2019 and trends in the transformation of social-economic space confirm the insufficient level of influence of current methods of regulating migration flows. Along with this, the presence of a characteristic asymmetry in the distribution of migrants requires a greater focus on the modernization of regulatory instruments, in particular, the regulatory mechanism for managing migration processes. As a result of the conducted study, further prospects for the implementation of alternative methods of regulating migration processes in EU states have been outlined; the current and projected limits for increasing the level of observance of migrants' rights at the European level have been clarified through the adoption of appropriate regulatory acts; effective solutions for intensifying the influx of high-quality labor resources from different countries to EU have been identified. The research results can be used to study methods of regulating migration processes in the countries in the global dimension.

• 디지털융복합연구
• /
• 제19권3호
• /
• pp.245-251
• /
• 2021

본 연구에서는 지르코니아의 새로운 표면처리 방법이 레진 시멘트와의 전단결합강도에 미치는 영향을 알아보고자 하였다. 지르코니아 표면처리 방법 따라 5개의 그룹으로 분류하였다: 표면처리 미시행한 군(CON군), 100℃에서 9% 불산에 10분간 노출시킨 군(HF군), 15% 지르코니아 슬러리를 적용한 군(ZS15군), 30% 지르코니아 슬러리를 적용한 군(ZS30군), 50% 지르코니아 슬러리를 적용한 군(ZS50군). 표면처리한 지르코니아 위에 레진 시멘트를 적용하였고, 열 순환 처리 후 지르코니아와 레진 시멘트 간의 전단결합강도를 측정하였다. 전단결합강도에 대한 통계 방법으로 Kruskal-Wallis test와 Mann-Whitney U test 및 Boneferroni correction를 사용하였다(α=.05/10=.005). 지르코니아 슬러리를 적용한 군은 CON군과 HF군에 비해 높은 전단결합강도를 보였다(p<.05/10=.005). 지르코니아 슬러리를 이용한 표면처리 방법은 레진 시멘트와 지르코니아 간의 전단결합강도를 증대시킴을 확인하였다. 본 연구 결과, 새로운 표면처리 방법은 지르코니아가 지닌 접착의 한계점을 보완하고 개선함으로써 지르코니아의 보다 다양한 임상적 적용 가능성을 기대할 수 있을 것으로 사료된다.

• 한국조경학회지
• /
• 제49권1호
• /
• pp.19-30
• /
• 2021

본 연구에서는 서울의 소규모 유휴공간을 시민참여의 방식으로 재생하는 "72시간 프로젝트" 사업의 경관적 개선 효과를 분석하였다. 2016년부터 2019년까지 조성된 29개소의 작품을 연구의 대상으로 삼았다. 12개의 경관형용사 쌍을 활용한 작품 조성 전·후의 경관 이미지 선호도를 분석하였으며, 설문 조사 결과를 바탕으로 기술 통계량 분석, 상관관계 분석, 요인분석, 군집분석, 분산분석을 시행하였다. 조성 후의 만족도는 3.63으로 프로젝트의 결과, 경관 개선의 효과가 있는 것으로 나타났다. 요인분석을 통해 조화성과 심미성이라는 두 가지 요인이 도출되었고, 군집분석을 진행하여 네 가지 군집 별 작품의 특성을 파악할 수 있었다. 군집분석의 결과, 조화성과 심미성이 모두 높은 군집이 종합만족도 평균도 가장 높았다. 다른 군집의 특성을 비교할 때 만족도 평가 시 조화성이 심미성보다 중요한 요인으로 작용하였다. 작품군의 정성적인 특징을 분석한 결과, 식재 면적이 풍부하며 시각적으로 두드러지는 시설물 중심의 설계보다는 공간적으로 균형감이 있는 설계가 경관 개선 효과가 크다는 결론을 도출하였다. 본 연구는 향후 이용자 행태 연구를 통해 보완될 필요성이 있으며, 향후 다양한 소규모 유휴공간 재생 사업의 발전적 방향을 수립하는데 기여할 수 있는 자료로 활용될 수 있을 것으로 기대된다.

• 한국산업보건학회지
• /
• 제32권4호
• /
• pp.402-413
• /
• 2022

Objectives: In this study, the scale of exceeding the extreme heat exposure standard at the construction site was estimated using the nationally approved statistical data and wet bulb globe temperature modeling method. By comparing and analyzing the modeling results with the existing work environment monitoring results, the risk of heat exposure at outdoor construction sites was considered. Methods: Using the coordinates of second level administrative districts and meteorological observatories as the key, the automated synoptic observing system data and building permit data for 2021 were matched. The wet-bulb temperature was obtained using Stull's formula, and the globe temperature was obtained using the Tg_KMA2006 model. WBGT was calculated using these. Excess rates were obtained compared to exposure limits for heavy work-continuous work and moderate work-25% rest. It was compared with the results of the work environment monitoring in 2020. Results: As a result, 1,827,536 cases were estimated for 11,052 workplaces in one year. This is much higher than the 5,116 cases of 3818 workplaces of the existing work environment monitoring results. It is confirmed that the exposure limit was exceeded in 10.6~24.0% of the entire period and 70.2~84.1% of the peak period of the heat wave. It is very high compared to 0.9% of the existing work environment monitoring result. Conclusions: It is necessary to improve the system of monitoring and statistics related to extreme heat. Additional considerations are needed regarding WBGT estimation methods, meteorological data, and evaluation time. Various follow-up risk assessment studies for other industries and time series need to be continued.

• 한국가축번식학회지
• /
• 제9권2호
• /
• pp.133-139
• /
• 1985

An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.