• Journal of the Korea Concrete Institute
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• v.13 no.4
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• pp.371-378
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• 2001

Recently, the parameters, models, and experimentations, which evaluate the fracture properties of concrete, have been proposed by many researchers, and their developments allow us to analyze the non-linear and quasi-brittle fracture mechanisms. In this paper, a brief treatment of the fracture parameters was presented and the experiments of 3-point bending tests were conducted to compare J-integral($J_{Ic}$ /) with other parameters($K_{Ic}$ , $G_{v}$ , and $G_{F}$ ). The change of parameter values according to the width and notch length of concrete beam specimens was also considered. The load-displacement curves are used to experimentally measure concrete fracture toughness. From the results of experiment, it is noted that the value of $GF$ and tic decreases as the notch depth increases and $G_{F}$ is less sensitive than $J_{Ic}$ . Therefore, the former is more appropriate to use as the concrete fracture toughness parameter. The values of $v_{v}$ and $J_{Ic}$ increase when the width of concrete specimens increase from 75 mm to 150 mm. Therefore, the effects of specimen width need to be considered in determining the concrete fracture toughness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.771-775
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• 2005

The growth inhibitory effects on human cancer cell lines provide useful information regarding critical cellular targets. Reports on cytotoxicity of Gloiopeltis furcata (GF) to human cancer cell lines are conflicting. This study was performed to investigate the effects of cytotoxicity and quinone reductase activity of Gloiopeltis furcata on the human cancer cells. The four partition layers of methanol extracts (GFM) which are hexane (GFMH), methanol (GFMM), butanol (GFMB) and aquous (GFMA) were screened for their cytotoxic effects on HepG2, HeLa, MCF-7, HT-29, and normal liver cell lines. The GFMM showed the strongest growth inhibition effect on all cell lines we used. the GFMM showed the highest induction activity of quinone reductase on HepG2 cells among the other partition layers.

• Allergy, Asthma & Immunology Research
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• v.10 no.6
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• pp.591-613
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• 2018

Chronic cough is common in the community and causes significant morbidity. Several factors may underlie this problem, but comorbid conditions located at sensory nerve endings that regulate the cough reflex, including rhinitis, rhinosinusitis, asthma, eosinophilic bronchitis, and gastroesophageal reflux disease, are considered important. However, chronic cough is frequently non-specific and accompanied by not easily identifiable causes during the initial evaluation. Therefore, there are unmet needs for developing empirical treatment and practical diagnostic approaches that can be applied in primary clinics. Meanwhile, in referral clinics, a considerable proportion of adult patients with chronic cough are unexplained or refractory to conventional treatment. The present clinical practice guidelines aim to address major clinical questions regarding empirical treatment, practical diagnostic tools for non-specific chronic cough, and available therapeutic options for chronic wet cough in children and unexplained chronic cough in adults in Korea.

• Tuberculosis and Respiratory Diseases
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• v.82 no.1
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• pp.27-34
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• 2019

Background: Understanding the burden of disease is important to establish cost-effective treatment strategies and to allocate healthcare resources appropriately. However, little reliable information is available regarding the overall economic burden imposed by chronic obstructive pulmonary disease (COPD) in Korea. Methods: This study is a multicenter observational research on the COPD burden in Korea. Total COPD costs were comprised of three categories: direct medical, direct non-medical, and indirect costs. For direct medical costs, institutional investigation was performed at 13 medical facilities mainly based on the claims data. For direct non-medical and indirect costs, site-based surveys were administered to the COPD patients during routine visits. Total costs were estimated using the COPD population defined in the recent report. Results: The estimated total costs were approximately 1,245 million US dollar (1,408 billion Korean won). Direct medical costs comprised approximately 20% of the total estimated costs. Of these, formal medical costs held more than 80%. As direct non-medical costs, nursing costs made up the largest percentage (39%) of the total estimated costs. Costs for COPD-related loss of productivity formed four fifths of indirect costs, and accounted for up to 33% of the total costs. Conclusion: This study shows for the first time the direct and indirect costs of COPD in Korea. The total costs were enormous, and the costs of nursing and lost productivity comprised approximately 70% of total costs. The results provide insight for an effective allocation of healthcare resources and to inform establishment of strategies to reduce national burden of COPD.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.64-77
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• 2021

Objective: Biological monitoring of trace elements in human blood samples has become an important indicator of the health environment. The purpose of this study was to detect and evaluate multiple metal items in blood samples based on ICP-MS, to perform comparative evaluation with the existing analysis method, and to develop and verify a new method. Methods: 100 μL of whole blood from 80 healthy subjects was used to analyze ten metals (Sb, tAs, Cd, Pb, Mn, Hg, Mo, Ni, Se, Tl) using ICP-MS. Verification of the analysis method included calculation of linearity, accuracy, precision and detection limits. In addition, a comparative test with the conventional graphite furnace atomic absorption spectroscopy (GF-AAS) method was performed. In the case of Pb, Cd, and Hg in whole blood, cross-analysis between Pb, Cd, and Hg analysis methods was performed to confirm the difference between the existing method and the new method (ICP-MS). Results: The coefficient of determination (R2) was 0.999 or higher in seven items and 0.995 or higher in three items. The Pb result showed that Pearson's correlation coefficient was very high at 0.983, and the intraclass correlation coefficient was 0.966. The Cd result showed that Pearson's correlation coefficient was 0.917 between the existing method and the new analysis concentration value. Its intraclass correlation coefficient was 0.960, and there was no significant difference between the two groups. Hg had a low correlation at 0.687, and the intraclass correlation coefficient was 0.761, which was lower than that of Pb and Cd. The intra-day and inter-day accuracy of Pd and Cd were satisfactory, but Hg did not meet the criteria for both accuracy and precision when compared with the conventional analysis method. Conclusion: This study can be meaningful in that it proposes a more efficient and feasible analysis method by verifying a blood heavy metal concentration experiment using multiple simultaneous analyses. All samples were processed and analyzed using the new ICP-MS. It was confirmed that the agreement between the two methods was very high, with the agreement between the current and new methods being 0.769 to 0.998. This study proposes an efficient simultaneous methodology capable of analyzing multiple elements with small samples. In the future, studies of various applications and the reliability of ICP-MS analysis methods are required, and research on the verification of accurate, precise, and continuous analysis methods is required.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.179-187
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• 2003

Recently efficient implementation of finite field operation has received a lot of attention. Among the GF($2^m$) arithmetic operations, multiplication process is the most basic and a critical operation that determines speed-up hardware. We propose a hardware architecture using Mastrovito method to reduce processing time. Existing Mastrovito multipliers using the special generating trinomial p($\chi$)=$x^m$+$x^n$+1 require $m^2$-1 XOR gates and $m^2$ AND gates. The proposed multiplier needs $m^2$ AND gates and $m^2$＋($n^2$-3n)/2 XOR gates that depend on the intermediate term xn. Time complexity of existing multipliers is $T_A$+( (m-2)/(m-n) +1+ log$_2$(m) ) $T_X$ and that of proposed method is $T_X$＋(1＋ log$_2$(m-1)＋ n/2 ) )$T_X$. The proposed architecture is efficient for the extension degree m suggested as standards: SEC2, ANSI X9.63. In average, XOR space complexity is increased to 1.18% but time complexity is reduced 9.036%.

• Herbal Formula Science
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• v.31 no.1
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• pp.11-19
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• 2023

Objectives : The purpose of this study was to examine the effects of herbal medicines on pacemaker potentials of large intestinal interstitial Cells of Cajal (ICC) in mice. Methods : We made the ICC culture in large intestine in mice and used the electrophysiological method to record pacemaker potentials. Also we used MTT assay to check cell viability and examined the ICC protein expression by western blot. Results : 1.Glycyrrhiza uralensis Fischer (GF) (50-150 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 58.95 ㎍/ml. Angelica gigas (AG) (50-200 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 77.22 ㎍/ml. Poncirus fructus (PF) (10-100 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 13.39 ㎍/ml. Citrus unshiu S. Marcov. (CU) (10-500 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 139.80 ㎍/ml. Gardenia jasminoides J. Ellis (GJ) (100-500 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 78.70 ㎍/ml. Coptis chinensis (CC) (100-1000 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 138.10 ㎍/ml. Scutellaria baicalensis (SB) (10-100 ㎍/ml) had no effects on pacemaker potentials and decreased frequency with concentration-dependent manners. IC₅₀ is 18.34 ㎍/ml. Atractylodes macrocephala koidzumi (AM) (10-100 ㎍/ml) induced pacemaker hyperpolarizations and decreased frequency with concentration-dependent manners. IC₅₀ is 18.54 ㎍/ml. 2. PF, SB and AM had no effects on cell death in large ICC. 3. PF increased the ANO1 and c-kit protein expression and SB and AM increased the c-kit protein expression in large ICC. Conclusions : These results suggest that PF, SB, and AM are likely to be the optimal combination of herbal medicines that can be used to treat diseases such as gastrointestinal motility disorders such as irritable bowel syndrome.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.638-646
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• 2023

Recently, active research has been conducted to enhance the power characteristics and thermal stability of lithium-ion batteries (LiBs) by modifying separators using a ceramic coating method. However, since the thermal properties and surface features of the separator vary depending on the characteristics of the ceramic powders applied to the separator, it is crucial to manufacture ceramic powders optimized for the separator's performance. In this study, we evaluated the characteristics of three types of α-alumina (A-1, A-2, and A-3) produced with varying dispersant contents and milling times, in addition to commercial α-alumina (AES-11). Subsequently, the optimized powders (A-3) were coated onto the separator using an aqueous binder for comparison with the characteristics of an AES-11 coated separator and an uncoated PE separator. The A-3 coated separator improved electrolyte wettability with a low contact angle (44.69°) and increased puncture strength (538 gf). Furthermore, it exhibited excellent thermal stability, with a shrinkage value of 5.64% when exposed to 140℃ for 1 hour, compared to the AES11 coated separator (6.09%) and the bare PE separator (69.64%).

• IMMUNE NETWORK
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• v.1 no.3
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• pp.244-249
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• 2001

The transforming growth $factor-{\beta}$ ($TGF-{\beta}$) is a multifunctional cytokine modulating the onset and course of autoimmune disease as shown in experimental models. In synovial inflammation, there is a potential role for $TGF-{\beta}$ in repairment, the inhibition of cartilage and bone destruction, and the down-regulation of immune response. The biologic effects of $TGF-{\beta}$ depend on the cell type, the isoform and the availability of active $TGF-{\beta}$. We investigated $TGF-{\beta}$ expression in patients with rheumatoid arthritis (RA) and compared to those of osteoarthritis (OA). And we determined a correlation between $TGF-{\beta}1$ and $TGF-{\beta}2$, and also the relationships between each $TGF-{\beta}$ isoform and the parameters for disease activity of RA. Methods: The study population consisted of 20 patients with RA and 20 patients with OA. The commercial ELISA kit was used to study $TGF-{\beta}1$ and $TGF-{\beta}2$ levels in peripheral blood (PB) and synovial fluids (SF). Results: 1) While PB $TGF-{\beta}1$ level was of no difference between RA and OA patient groups, SF $TGF-{\beta}1$ level was higher in RA group than OA group. Similarly, PB $TGF-{\beta}2$ levels of RA and OA groups was not different, but SF $TGF-{\beta}2$ levels was higher in RA group than OA group. 2) In patients with RA, the $TGF-{\beta}1$ levels were higher than $TGF-{\beta}2$ in both the PB and SF, while in patients with OA, there showed higher readings for $TGF-{\beta}1$ than $TGF-{\beta}2$ in SF but no difference between $TGF-{\beta}1$ and $TGF-{\beta}2$ levels in PB. 3) In patients with RA, there were no correlations between PB $TGF-{\beta}1$ and PB $TGF-{\beta}2$ levels, nor between SF $TGF-{\beta}1$ and SF $TGF-{\beta}2$ levels. At the same way, there was no correlation between PB $TGF-{\beta}1$ and SF $TGF-{\beta}1$ levels, nor between each levels of $TGF-{\beta}2$ in patients with RA. 4) There was also no correlation between each $TGF-{\beta}$ isoform and the parameters for disease activity such as ESR, CRP, tender joint count, swollen joint count, rheumatoid factor, and the duration of morning stiffness except between in PB $TGF-{\beta}1$ and disease duration of RA (r=0.637, p<0.01). Conclusion: Each $TGF-{\beta}$ isoforms were higher in synovial fluid of patients with RA than that of patients with OA. The data from the RA patients demonstrated different patterns of expressions of the isoforms depending on which compartment (PB or SF) was investigated. The quantification of different $TGF-{\beta}$ isoform is thought to be important when $TGF-{\beta}$ is measured under disease conditions of RA.

• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.133-140
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• 2012

Movement and accumulation of cadmium in male Sprague-Dawley rats, fed with brown rice from nearby Janghang smeltery area were investigated. The rat fed with five different cadmium level diets made with Cd-polluted during 12 weeks. The brown rice-polluted with 0.87 ppm Cd (PBR) was sampled from products in the Janghang smeltery area. Diets of brown rice group were brown rice (BR, 0.002 ppm Cd), each 50% of BR and PBR (BR+PBR 50%, 0.44 ppm Cd) and PBR (PBR 100%, 0.87 ppm Cd). To compare with BR+PBR 50%, the another group diet composed the feed (FE, 0.002 Cd ppm) and each 50% of FE and PBR (FE+PBR 50%, 0.44 ppm Cd). Accumulation of Cd, Zn and Cu in blood, liver and kidney rats was measured by GF-AAS. The weight gain in BR groups and FE groups were different 0.22-0.26 and 1.08-1.26 g/day, respectively. Daily intake cadmium was 10.77 and 22.36 ${\mu}g/rat$ in BR+PBR 50% and PBR 100%, and 8.83 ${\mu}g/rat$ in FE+PBR 50%. Cadmium contents in diets were higher, and total intake of the heavy metals was more increased on the whole. Weights of liver and kidney in FE+PBR 50% group was 2.64 and 2.27 folds higher than those in BR+PBR 50% group. Cadmium contents in blood were increased with intake of BR diet, but Zn and Cu were decreased with them. In the diet groups with the same Cd concentration, Cd content of FE+PBR 50% was higher 1.27 times than that of BR+PBR 50%. In the diet group of BR, BR+PBR 50%, and PBR 100%, the increase of Cd concentration was significantly different to the increase of Cd content in the livers. In the same condition of Cd concentration, Cd contents were higher in the BR+PBR 50% group. In the diet groups of BR, BR+PBR 50%, and PBR 100%, the increase of Cd content in the kidneys led to the increase of Zn and Cu contents. In the same condition of Cd concentration, the diet group with the addition of BR was shown to be 3.11 times higher than with the addition of FE. In view of the results so far achieved, It was closely related with Cd, Zn, and Cu content.