• 분석과학
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• 제18권1호
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• pp.23-26
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• 2005

셀렌은 항산화 작용을 하는 미량 원소로 잘 알려져 있으며 많은 고객들은 다양한 식품시료중의 셀렌의 농도 및 정량에 관심을 갖고 있다. 본 연구에서는 $^{75}Se$과 $^{77m}Se$ 핵종을 이용한 중성자 방사화 분석법에 의한 생물시료중의 셀렌 분석법을 확립하고 비교하고자 하였다. 이를 위하여 미국표준연구원의 3종의 인증 표준물질을 선택하여 미리 설정된 분석조건 (조사, 냉각 및 측정시간) 하에서 셀렌의 농도를 결정하였다. 두 가지 분석방법에 의한 측정값을 인증값과 평가하였으며 $^{75}Se$과 $^{77m}Se$의 측정값에 대한 검출한계와 불확도를 서로 비교 하였다.

• 분석과학
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• 제5권4호
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• pp.349-358
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• 1992

본 연구에서는 흑연로 원자흡수분광법을 이용하여 혈액을 1% Triton X-100을 5배 희석시킨 다음 납 함량을 직접 측정하였다. 혈액내 방해 성분을 제거하기 위하여 매트릭스 변형제를 사용하여 최적의 분석 조건을 조사하였다. 매트릭스 변형제로서 1% $(NH_4)_2HPO_4$와 0.1% $PdCl_2$를 같이 사용하고 700도에서 회화시켰을 때에, 일본 비교 분석 프로그램에 의해 제공된 혈중 납 함량에 대한 정도관리용 표준시료(우혈)의 공인값과 비교적 잘 일치하였다. 이 실험에서 얻은 표준편차는 $31{\mu}gPb/l$에서 $624{\mu}gPb/l$ 범위에서는 1% $(NH_4)_2HPO_4$ 및 1% $(NH_4)_2HPO_4$와 0.1% $PdCl_2$를 매트릭스 변형제로서 사용했을 경우 각각 2.2~6.3%, 3.1~9.1%였다.

• Nutrition Research and Practice
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• 제11권1호
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• pp.33-42
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• 2017

BACKGROUND/OBJECTIVE: This study aims to measure the in vitro antioxidant capacity of Korean diet (KD) with American diet (AD) as a control group and to examine the ex vivo DNA damage reduction effect on human lymphocytes. MATERIALS/METHODS: The KD applied in this study is the standard one-week meals for Koreans (2,000 kcal/day) suggested by 2010 Dietary Reference Intakes for Koreans. The AD, which is the control group, is a one-week menu (2,000 kcal/day) that consists of foods that Americans would commonly take in according to the National Health and Nutrition Examination Survey. The antioxidant capacity of each menu was measured by means of the total phenolic assay and 3 in vitro antioxidant activity assays (2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, trolox equivalent antioxidant capacity (TEAC), Oxygen radical absorbance capacity ($ORAC_{ROO{\cdot}}$)), while the extent of ex vivo lymphocyte DNA damage was measured by means of the comet assay. RESULTS: When measured by means of TEAC assay, the in vitro antioxidant capacity of the KD of the day was higher than that of the AD (P < 0.05) while there was no significant difference in total phenolic contents and DPPH and ORAC assays. The ex vivo lymphocyte DNA damage protective effect of the KD was significantly higher than that of the AD (P < 0.01). As for the one-week menu combining the menus for 7 days, the total phenolic assay (P < 0.05) and in vitro antioxidant capacity (P < 0.001, DPPH; P < 0.01, TEAC) of the KD menu were significantly higher than those of the AD menu. Likewise, the ex vivo DNA damage reduction rate of the Korean seven-day menu was significantly higher than that of the American menu (P < 0.01). CONCLUSION: This study demonstrates that the high antioxidant capacity and DNA damage protective effect of KD, which consists generally of various plant foods, are higher than those of typical AD.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2361-2368
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• 2015

Objective: To evaluate the diagnostic accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating between benign and malignant enlarged lymph nodes using meta-analysis. Materials and Methods: Pubmed, Embase, SCI and Cochrane databases were searched for studies (up to September 1, 2014) reporting the diagnostic performance of CEUS in discriminating between benign and malignant lymph nodes. Inclusion criteria were: prospective study; histopathology as the reference standard; and sufficient data to construct $2{\times}2$ contingency tables. Methodological quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Patient clinical characteristics, sensitivity and specificity were extracted. The summary receiver operating characteristic curve was used to examine the accuracy of CEUS. A meta-analysis was performed to evaluate the clinical utility in identification of benign and malignant lymph nodes. Sensitivity analysis was performed after omitting outliers identified in a bivariate boxplot and publication bias was assessed with Egger testing. Results: The pooled sensitivity, specificity and AUROC were 0.92 (95%CI, 0.85-0.96), 0.91 (95%CI, 0.82-0.95) and 0.97 (95%CI, 0.95-0.98), respectively. After omitting 3 outlier studies, heterogeneity decreased. Sensitivity analysis demonstrated no disproportionate influences of individual studies. Publication bias was not significant. Conclusions: CEUS is a promising diagnostic modality in differentiating between benign and malignant lymph nodes and can potentially reduce unnecessary fine-needle aspiration biopsies of benign nodes.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8335-8338
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• 2016

Purpose: To make a comparison of single voxel magnetic resonance spectroscopy (SV-MRS) and dynamic contrast enhancement (DCE) MRI for differentiation of benign and malignant breast lesions in a sample of Iranian women. Materials and Methods: A total of 30 women with abnormal breast lesions detected in mammography, ultrasound, or clinical breast exam were examined with DCE and SV-MRS. tCho (total choline) resonance in MRS spectra was qualitatively evaluated and detection of a visible tCho peak at 3.2 ppm was defined as a positive finding for malignancy. Different types of DCE curves were persistent (type 1), plateau (type 2), and washout (type 3). At first, lesions were classified according to choline findings and types of DCE curve, finally being compared to pathological results as the standard reference. Results: this study included 19 patients with malignant lesions and 11 patients with benign ones. While 63.6 % of benign lesions (7 of 11) showed type 1 DCE curves and 36.4% (4 of 11) showed type 2, 57.9% (11of 19) of malignant lesions were type 3 and 42.1% (8 of 19) type 2. Choline peaks were detected in 18 of 19 malignant lesions and in 3 of 11 benign counterparts. 1 malignant and 8 benign cases did not show any visible resonance at 3.2 ppm so SV-MRS featured 94.7% sensitivity, 72.7 % specificity and 86.7% accuracy.Conclusions: The present findings indicate that a combined approach using MRS and DCE MRI can improve the specificity of MRI for differentiation of benign and malignant breast lesions.

• The Journal of Advanced Prosthodontics
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• 제10권4호
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• pp.328-334
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• 2018

PURPOSE. To evaluate the reproducibility of scan-based abutments using a blue light model scanner. MATERIALS AND METHODS. A wax cast abutment die was fabricated, and a silicone impression was prepared using a silicone material. Nine study dies were constructed using the prepared duplicable silicone, and the first was used as a reference. These dies were classified into three groups and scanned using a blue light model scanner. The first three-dimensional (3D) data set was obtained by scanning eight dies separately in the first group. The second 3D data set was acquired when four dies were placed together in the scanner and scanned twice in the second group. Finally, the third 3D data set was obtained when eight dies were placed together in the scanner and scanned once. These data were then used to define the data value using third-dimension software. All the data were then analyzed using the non-parametric Kruskal-Wallis H test (${\alpha}=.05$) and the post-hoc Mann-Whitney U-test with Bonferroni's correction (${\alpha}=.017$). RESULTS. The means and standard deviations of the eight dies together were larger than those of the four dies together and of the individual die. Moreover, significant differences were observed among the three groups (P<.05). CONCLUSION. With larger numbers of abutments scanned together, the scan becomes more inaccurate and loses reproducibility. Therefore, scans of smaller numbers of abutments are recommended to ensure better results.

• 한국의류산업학회지
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• 제12권2호
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• pp.203-213
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• 2010

This study examined the wearing conditions of working clothes of shipbuilding industry workers according to the working environmental factors and working process features. It was also investigated the relationship between the wearing sense of working clothes and the overall comfort according to work processes. In the working process of shipbuilding industry, the process of fitting, welding, grinding and painting were chosen by considering work environmental factors, disaster types, hazardous materials, work process features, working clothes and safety equipments of each work categorized. The workers of fitting process usually wore the standard working clothes, while more than 60% of the workers of welding, grinding and painting wore the specialized protective clothes. The hazardous work environmental factors such as noise, heavy dust, high temperature and noxious fumes affected to the workers of fitting, welding and grinding. However, the workers of painting were greatly damaged by organic solvent. The dissatisfaction with the wearing performance of working clothes was highly shown in the sweat absorbency, moisture permeability and body protection. In respect of the correlation between the overall comfort and the wearing sense of working clothes, the satisfaction was decreased in orders of movement comfort> sensual comfort> physiological comfort.

• Investigative Magnetic Resonance Imaging
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• 제20권3호
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• pp.167-174
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• 2016

Purpose: To identify magnetic resonance imaging (MRI) findings of leukemic infiltration of optic nerve and optic neuritis in leukemic patients with emphasis of clinical findings as reference standard to differentiate them. Materials and Methods: MRI and clinical findings of 7 patients diagnosed as leukemic infiltration of optic nerve (n = 5) and optic neuritis (n = 2) in our institution between July 2006 and August 2015were reviewed retrospectively. In particular, MR imaging findings involved perineural enhancement and thickening of optic nerve and its degree, signal intensity, laterality (unilateral/bilateral), intraconal fat infiltration and its degree, and associated central nervous system abnormalities. Results: Of 5 cases of leukemic infiltration of optic nerve, 4 cases showed positive cerebrospinal fluid (CSF) study for leukemia relapse and 1 case was positive on bone marrow (BM) biopsy only. Moreover, of 5 leukemic infiltration of optic nerve, 2 cases showed the most specific MR findings for leukemic central nervous system involvement including 1 prominent leptomeningeal enhancement and 1 chloroma. However, other MR imaging findings of the patients with leukemic infiltration or optic neuritis such as thickening and perineural enhancement of optic nerves are overlapped. Conclusion: Enhancement and thickening of optic nerve were overlapped MR findings in leukemic infiltration of optic nerve and optic neuritis. Our findings suggest that enhancing optic nerve thickening with associated central nervous system MR abnormality favors the diagnosis of leukemic infiltration of optic nerve, especially in patients with history of acute lymphoblastic leukemia. However, CSF and BM study were required for differentiation between leukemic infiltration of optic nerve and optic neuritis.

• 한국식품영양학회지
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• 제32권6호
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• pp.745-752
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• 2019

The purpose of this study was to determine the difference in vitamin B₆ content according to the varieties, regions, and harvest times of vegetables and fruits in Korea using high performance liquid chromatography. We verified the accuracy of the analytical method with standard reference material 1849a and achieved reliability for internal analysis quality control with a mixture of cereal, whole wheat, and flour. As a result of the analysis, vitamin B₆ contents (㎍/100 g) were 6.9~86.5 in peppers, 5.1~17.2 in paprika, 4.4~5.0 in strawberries, 4.0~52.9 in tomatoes, 7.7~7.8 in Chinese cabbage, 17.3~23.3 in radishes, 13.4~37.6 in apples, 2.3~12.7 in peaches, and 3.7~12.7 in grapes. In general, the difference in vitamin B₆ content showed by varieties, harvest times, and regions. Peppers showed the most difference as 79.6 ㎍/100 g among the varieties, and apples showed a difference as 22.8 ㎍/100 g by regions. According to the harvest times in grape 'Mihwang', there was a difference of 7.5 ㎍/100 g. We will collect an amount of nutritional data on various food materials, and continue to build a reliable and integrated nutritional database. And then the database will be used in the 10th revision of the Korean Food Composition Table.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1447-1452
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• 2012

Aim: To evaluate the differential diagnostic potential of lesion stiffness assessed by the sonoelastographic strain index ratio (SR) and elastographic color scoring system (UE) for breast lesions. Materials and Methods: Three hundred and forty two breast masses (158 benign and 184 malignant) from 325 consecutive patients (mean age 44.2 years; range 16-81)who had been scheduled for a sonographically guided core biopsy were examined proposed by Itoh et al, with scoring 1-3=benign and 4-5=malignant. Strain and area ratios of each lesion were calculated within the same machine. Histological diagnosis was used as the reference standard. The area under the curve (AUC) and cut-off point were obtained by receiver operating curve and the cross table Fischer Test was carried out for assessing diagnostic value. Sensitivity, specificity, PPV, NPV, accuracy and false-discovery rates were compared. Results: The mean strain ratios for benign and malignant lesions were 1.87 and 7.9 respectively. (P<0.0001). When a cutoff point of 3.54 was used, SR had a sensitivity of 94.6%, a specificity 94.3%, a PPV of 95.1%, an NPV of 93.7% and an accuracy of 94.4%. The AUC values were 0.90 for the 5 point scoring system (UE) and 0.96 for the strain index ratio. The overall diagnostic performance was SR method was better (P<0.05). Conclusions: Strain ratio measurement could be another effective predictor in elastography imaging besides 5 the point scoring system for differential diagnosis of breast lesions.