• 대한임상검사과학회지
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• 제46권3호
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• pp.79-84
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• 2014

Children and adolescents normally have higher Alkaline phosphatase levels than adults. This study was conducted to provide basic data about pediatric reference intervals for ALP. The data from the 2011 Korean National Health and Nutrition Examination Survey was used. Analysis was done for 847 Children and Adolescents (443 boys and 404 girls) aged 10 to 19. The method of p-NPP & EAE buffer was used to get the data. The highest ALP levels were found in boys aged 12 to 13, the reference interval being 653~1,518 IU/L; the levels decreased for those over 13 years old. In the case of girls, the highest ALP levels were found with those aged between 11 and 12, the reference interval being 463~1,598 IU/L; the levels decreased after 12 years of age. The mean difference in all age groups was statistically significant, except for those aged 10 to 11 and 11 to 12. Therefore, it is suggested that pediatric reference intervals should be divided into three groups according to gender. Complementing data about children and adolescents below 10 years old were not included in this study and will be much needed in the next trial.

• 한국콘텐츠학회논문지
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• 제11권3호
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• pp.302-308
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• 2011

혈관 조영 검사 및 중재적 방사선 시술을 통한 환자에게 주어지는 피폭선량에 대해 대뇌를 중심으로 환자 체형을 표준화하여 검사 및 시술 차이에 따른 투시시간, 면적 선량률(kerma area product rate)을 관측하고 참고 기준치를 비교하고자 하였다. 그 결과 질병 분류에 따른 면적 선량률은 지주막하출혈(subarachnoid hemorrhage)이 가장 높았고, 뇌동맥류가 가장 낮았다. 또한 검사 및 시술에 따른 면적 선량률은 양쪽 내경동맥, 양쪽 총경동맥 및 추골동맥으로 하는 방법이 가장 높았으며, guglielmi detachable coil(GDC)이 가장 낮게 나타났다. 따라서 이를 혈관 조영 검사 및 중재적 방사선 시술시 환자 피폭 선량에 대한 참고 기준치로 이용할 수 있을 것이며 향후 환자 피폭 선량 교육과 관리에 유용할 것이라 사료된다.

• 한국산림과학회지
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• 제111권4호
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• pp.603-612
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• 2022

본 연구는 다중시기 위성영상과 머신러닝 알고리즘을 이용하여 준국가수준의 시계열 산림바이오매스량을 추정하였으며, 이를 바탕으로 산림배출기준선 설정하여 비교·분석하였다. 머신러닝기반의 산림바이오매스 추정 모델을 구축하기 위하여 Landsat TM 위성영상과 유럽항공우주국에서 제공하는 Biomass Climate Change Initiative 정보를 이용하였으며, 머신러닝 알고리즘은 비모수 학습모델인 k-Nearest Neighbor(kNN)과 의사결정나무 기반의 Random Forest(RF)를 적용하였다. 또한, 추정된 산림바이오매스량은 Forest reference emission levels(FREL) 자료와 비교하였다. 머신러닝 알고리즘 별 산림바이오매스 추정 모델을 비교해보면, 최적의 kNN 모델과 RF 모델의 Root Mean Square Error (RMSE)는 각각 35.9와 34.41였으며, RF모델이 kNN모델보다 상대적으로 우수하였다. 또한, FREL, kNN, RF 모델 별 산림배출기준선의 기울기는 각각 약 -33천ton, -253천ton, -92천ton으로 설정되었다.

• 분석과학
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• 제34권5호
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• pp.202-211
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• 2021

Volatile organic compounds (VOCs) in hazardous air pollutants (HAPs) have been regulated by the Air Pollution Control Act (1978) and their atmospheric concentrations have been monitored in 39 monitor sites in Korea. However, measurement standards of volatile organic compounds (VOCs) in HAPs at ambient levels have not been established in Korea. Primary reference gas mixtures (measurement standards) at ambient levels are required for accurately monitoring atmospheric VOCs in HAPs and managing their emissions. In this study, primary reference gas mixtures (PRMs) at 5 nmol/mol were developed in order to establish primary national standards of VOCs in HAPs at ambient levels. Primary reference gas mixtures (PRMs) were prepared in pressurized aluminum cylinders with special internal surface treatment using gravimetric method. Analytical methods using gas chromatography-flame ionization detector (GC-FID) coupled with a cryogenic preconcentrator were also developed to verify the consistency of gravimetrically prepared HAP VOCs PRMs. Three different columns installed in the GC-FID were evaluated and compared for the retention times and separation of eighteen target components in a chromatogram. Results show that the HAP VOCs PRMs at 5 nmol/mol were consistent within a relative expanded uncertainty (k=2) of less than 3 % except acrylonitrile (less than 6 %) and the 18 VOCs were stable for 1 year within their associated uncertainties.

• 대한임상검사과학회지
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• 제40권2호
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• pp.86-93
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• 2008

This study was performed to investigation of the serum alpha-fetoprotein (AFP) levels in healthy adults. A total of 2,160 (male 1,415, female 745) health checkup adults were examined for AFP levels by chemiluminescence immunoassay (CLIA) method, during the period from September, 2007 to August, 2008. The mean serum AFP level was 2.168 (0.605~20.35) ng/mL, and it was 2.309 (0.605~20.35) ng/mL in male, 1.906 (0.605~10.36) ng/mL in female, respectively. 1,816 (male 1,109, female 709) healthy adults were screened for the absence of viral hepatitis and normal alanine amino transferase (ALT) levels. The mean serum AFP level of healthy adult was 2.041 (0.605~7.83) ng/mL, and it was 2.181 (0.605~7.83) ng/mL in male, 1.822 (0.605~6.55) ng/mL in female, respectively. Serum AFP increased with age group, there was a higher level in male compared to female. These results suggests that the use of reference value of AFP in healthy adults in the Jeonbuk. With the reference value now defined, it becomes possible to compare levels in different populations.

• 대한수의학회지
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• 제39권2호
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• pp.257-266
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• 1999

Ivermectin is a widely used broad spectrum antiparasitic agent in veterinary medicine. In this work, we examined the pharmacokinetic parameters and the tissue residue profile of a new injectable formulation of ivermectin developed for pigs. The plasma ivermectin levels reached the peak at about 9 and 2 hours after the administrations in young and adult pigs, respectively. But the elimination half-life (3-3.5 days) and the $C_{max}$ values (24~28 ng/ml) were not significantly different between young and adult pig groups. When compared to the reference formulation, the $C_{max}$ of test formulation was higher and $T_{1/2}$ values were shorter than those of the reference formulation, respectively. The tissue residue levels were dose- and time-dependent and were higher in the liver and fat, than in the other tissues such as the injection sites, the kidney, intestine, muscle, plasma (4~74 ng/g) at the 7th day after the administration of both formulations of ivermectin. Then, the mean tissue ivermectin levels at the 21st day after the administration in all the tissues decreased to 7.4 and 25% of the 7th day levels in the test and reference formulations, respectively. In general, the tissue levels of ivermectin in the animals treated with the test formulation decreased more rapidly than those with the reference formulation. The tissue to plasma distribution ratio (T/P ratio) of ivermectin was higher in the liver and fat than other tissues. The T/P ratio in the liver of animals treated with the test formulation was somewhat higher than that in the animals treated with the reference formulation. Taken together, the results of pharmacokinetic and tissue residue studies indicate that the test formulation of ivermectin for subcutaneous injection is comparable to the reference formulation, but unique in that it has higher peak plasma concentrations, shorter elimination half-life and higher T/P ratio in the liver than the reference formulation.

• Psychiatry investigation
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• 제15권12호
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• pp.1130-1134
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• 2018

Objective Trichotillomania is a relatively common illness whose neurobiology is poorly understood. One treatment for adult trichotillomania, n-acetyl cysteine (NAC), has antioxidative properties, as well as effects on central glutamatergic transmission. Preclinical models suggest that excessive oxidative stress may be involved in its pathophysiology. Methods Adults with trichotillomania provided a blood sample for analysis of compounds that may be influenced by oxidative stress [glutathione, angiotensin II, ferritin, iron, glucose, insulin and insulin growth factor 1 (IGF1), and hepcidin]. Participants were examined on symptom severity, disability, and impulsivity. The number of participants with out-of-reference range oxidative stress measures were compared against the null distribution. Correlations between oxidative stress markers and clinical measures were examined. Results Of 14 participants (mean age 31.2 years; 92.9% female), 35.7% (n=5) had total glutathione levels below the reference range (p=0.041). Other oxidative stress measures did not have significant proportions outside the reference ranges. Lower levels of glutathione correlated significantly with higher motor impulsiveness (Barratt Impulsiveness Scale sub-score) (r=0.97, p=0.001). Conclusion A third of patients with trichotillomania had low levels of glutathione, and lower levels of glutathione correlated significantly with higher motor impulsiveness. Because NAC is a precursor for cysteine, and cysteine is a rate limiting step for glutathione production, these results may shed light on the mechanisms through which NAC can have beneficial effects for impulsive symptoms. Confirmation of these results requires a suitable larger follow-up study, including an internal normative control group.

• Clinical and Experimental Pediatrics
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• 제59권3호
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• pp.114-119
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• 2016

Purpose: This study aimed to assess the reference values and factors influencing blood lead levels among Korean adolescents. Methods: The study population consisted of 1,585 adolescents (801 males, 784 females; aged 10-19 years) who participated in the Korea National Health and Nutrition Examination Survey 2010-2013. We analyzed blood lead concentrations in relation to demographic/lifestyle characteristics for all participants. "Reference values" of blood lead levels were calculated as the upper limit of the 95% confidence interval of the 95th percentile. Results: The average "reference value" for blood lead concentrations among Korean adolescents was $2.25{\mu}g/dL$ ($2.49{\mu}g/dL$ for males, $2.07{\mu}g/dL$ for females), and the geometric mean of the blood lead concentrations was $1.34{\mu}g/dL$. Males had higher blood lead concentrations than females (male, $1.48{\mu}g/dL$; female, $1.19{\mu}g/dL$; P<0.001). Elementary school students had higher blood lead concentrations than junior and senior high school students ($1.44{\mu}g/dL$ vs. $1.31{\mu}g/dL$, P<0.001). Participants living in detached houses had higher blood lead concentrations than those living in apartments (P<0.001) and current smokers had higher concentrations than nonsmokers or participants with secondhand smoke exposure (P<0.05). Additionally, participants with excessive alcohol consumption had higher levels than non-drinkers (P<0.001). Conclusion: This study provides national reference data on blood lead concentrations stratified by demographic and lifestyle factors among Korean adolescents. Further studies are needed to elucidate the relationship between increased lead exposure and demographic factors including type of housing.

• 아시아태평양코퍼스연구
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• 제2권1호
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• pp.35-45
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• 2021

With the wide spread of the Common European Framework of Reference (CEFR) scales, many studies attempt to apply them in routine teaching and rater training, while more evidence regarding criterial features at different CEFR levels are still urgently needed. The current study aims to explore complexity features that distinguish and predict CEFR proficiency levels in oral performance. Using a quantitative/corpus-based approach, this research analyzed lexical and syntactic complexity features over 80 transcriptions (includes A1, A2, B1 CEFR levels, and native speakers), based on an interview test, Standard Speaking Test (SST). ANOVA and correlation analysis were conducted to exclude insignificant complexity indices before the discriminant analysis. In the result, distinctive differences in complexity between CEFR speaking levels were observed, and with a combination of six major complexity features as predictors, 78.8% of the oral transcriptions were classified into the appropriate CEFR proficiency levels. It further confirms the possibility of predicting CEFR level of L2 learners based on their objective linguistic features. This study can be helpful as an empirical reference in language pedagogy, especially for L2 learners' self-assessment and teachers' prediction of students' proficiency levels. Also, it offers implications for the validation of the rating criteria, and improvement of rating system.

• Endocrinology and Metabolism
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• 제33권4호
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• pp.466-472
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• 2018

Background: Thyroid dysfunction is associated with negative neonatal and obstetric outcomes. Large differences in thyroid function reference intervals exist across different populations. These differences can be explained by population-specific factors, such as iodine status. Many countries in Latin America report iodine sufficiency, but relatively few countries have published up-to-date data on iodine levels and thyroid function in the overall population, and especially in pregnant women. We evaluated the iodine status of pregnant women in Chile and determined thyroid hormone reference ranges in this population. Methods: This was a prospective observational study of healthy Chilean women at their first prenatal visit before week 14. Thyroid-stimulating hormone (TSH), total thyroxine ($T_4$), free $T_4$, antithyroid peroxidase antibody (TPOAb), and iodine levels from spot urine samples were measured. Iodine status and the reference ranges for TSH were calculated. Results: A total of 1,022 pregnant women in the first trimester were selected. Urinary iodine levels were measured in 302 randomly-selected women. The median urinary iodine concentration was $173.45{\mu}g/L$ (interquartile range, 108.11 to 249.35).The reference ranges of TSH were calculated in 670 patients selected according to the National Academy of Clinical Biochemistry guidelines. The median TSH level was $1.88{\mu}IU/mL$ (2.5th percentile: 0.13 to 97.5th percentile: 5.37). Using the reference range in the 1,022 women, the prevalence of clinical hypothyroidism was 1.76%, and that of subclinical hypothyroidism was 3.92%. TPOAb positivity was more common in women with TSH levels above $3.5{\mu}IU/mL$. Conclusion: We found adequate iodine intake and a right-shifted distribution of serum TSH levels in pregnant women in Chile. The prevalence of hypothyroidism in our sample of pregnant women was higher than has been described in the literature.