• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.747-754
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• 2005

Liquid chromatographic methods with UV and fluorescence detection have been used to determine the levels of (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, and (-)-epigallocatechin gallate in Korean green tea infusions. The extracts of Korean green tea leaves or powders in water at various temperatures (100 ${^{\circ}C}$, 80 ${^{\circ}C}$, 60 ${^{\circ}C}$) and time, were washed with chloroform and re-extracted to ethyl acetate. The ethyl acetate phase was dried and re-dissolved in methanol and analyzed. Five catechin compounds were separated by gradient elution. The flavonoids were found decomposed on prolonged extraction, thus exhaustive extraction by a Soxhlet apparatus was found useless for green tea. Some unknown components were found in the extracts at 100 ${^{\circ}C}$. When the green tea was filtered and re-extracted with new fresh water, still some flavonoids were extracted. However, the contents of flavonoids in the third extract were found negligible. The flavonoid extraction rate of green tea powders was higher than that of green tea leaves, but flavonoid decomposition of green tea powders was also faster than that of green tea leaves. The traditional way of drinking green tea was found appropriate in view of flavonoids intake.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8495-8501
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• 2016

Purpose: This study was conducted to assess the agreement and differences between cervical self-sampling with a Kato device (KSSD) and gynecologist sampling for Pap cytology and human papillomavirus DNA (HPV DNA) detection. Materials and Methods: Women underwent self-sampling followed by gynecologist sampling during screening at two primary health clinics. Pap cytology of cervical specimens was evaluated for specimen adequacy, presence of endocervical cells or transformation zone cells and cytological interpretation for cells abnormalities. Cervical specimens were also extracted and tested for HPV DNA detection. Positive HPV smears underwent gene sequencing and HPV genotyping by referring to the online NCBI gene bank. Results were compared between samplings by Kappa agreement and McNemar test. Results: For Pap specimen adequacy, KSSD showed 100% agreement with gynecologist sampling but had only 32.3% agreement for presence of endocervical cells. Both sampling showed 100% agreement with only 1 case detected HSIL favouring CIN2 for cytology result. HPV DNA detection showed 86.2%agreement (K=0.64, 95% CI 0.524-0.756, p=0.001) between samplings. KSSD and gynaecologist sampling identified high risk HPV in 17.3% and 23.9% respectively (p=0.014). Conclusion: The self-sampling using Kato device can serve as a tool in Pap cytology and HPV DNA detection in low resource settings in Malaysia. Self-sampling devices such as KSSD can be used as an alternative technique to gynaecologist sampling for cervical cancer screening among rural populations in Malaysia.

• Journal of the Korean Society of Radiology
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• v.9 no.7
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• pp.509-513
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• 2015

In this study, we evaluated the thermal denaturation characteristics of reusable NIPAM tissue mimicking (TM) Phantom by measuring the thermal sensitivity. And the changes of acoustic characteristic and thermal denaturation shape in NIPAM TM phantom according to the number of re-use time and re-use period were observed. With the result, as the sonication time is increased, the sound velocity of NIPAM phantom was decreased by 100 m/s and the attenuation was increased slightly. However, the changes according to the re-use period was not observed. In the thermal denaturation shape and size observation by ultrasound sonicaton, the remarkable changes have not been confirmed. With the result of this study, NIPAM Phantom was considered appropriate to evaluate and predict the effect of therapeutic ultrasound by in repeated sonication test.

• Korean Journal of Medicinal Crop Science
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• v.23 no.5
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• pp.406-413
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• 2015

Background : This study was carried out to investigate the changes to fatty acid, mineral, and ginsenosides contents in ginseng seed when they were stratified for different length of time and to determine whether variety had any effects on the changes. The aim was to improve the ginseng seed stratification process. Methods and Results : The ginseng varieties used were Geumpoong, Chunpoong, Yunpoong, and K-1. Stratifying periods treated on ginseng seed were 0, 20, 40, 60, 80, and 100 days. The main fatty acids of ginseng seed were oleic acid (C18 : 1, n9c) with a content of 78.40 - 79.20% followed by linoleic acid (C18 : 2, n6c). The main mineral in the seeds was potassium (K), at 1208.2 -1337.6 mg/100 g. The main ginsenosides in ginseng seed were ginsenoside Re and Rb1. Increasing the length of the stratification periods led to increases in oleic acid content (60 - 80 days), however after this the content declined. In contrast, linoleic acid content fell as the stratification period increased. K, P, Mg, Ca and Na content rose as the stratification period increased. The ginsenoside Re content of Chunpoong and K-1 cultivar seeds also rose as the stratification period increased which meant that total ginsenoside content increased. However, ginsenoside Re content rose in Geumpoong and Yunpoong seeds, but total ginsenoside content decreased as the stratification period increased. Conclusions : Some beneficial compound in ginseng seed rose as the stratification period increased. Therefore, ginseng seed stratification could improve the food value of ginseng.

• Journal of the Korean Magnetics Society
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• v.16 no.5
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• pp.234-239
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• 2006

We measured the microwave permeability in the frequency range of 100 MHz$\sim$9 GHz in the exchange biased CoFe/MnIr films. The results were analyzed based on the Landau-Lifshitz-Gilbert theory. The initial permeability and ferromagnetic resonance frequency was tuned by controlling the CoFe thickness and unidirectional anisotropy. The tunable range of ferromagnetic resonance frequency was up to 20 GHz in the thin CoFe layer of 1.5 nm. The CoFe/MnIr films showed the high permeability and low loss properties in the microwave frequency range. Thus, this material could be applied to the microwave devices.

• Safety and Health at Work
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• v.10 no.1
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• pp.39-46
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• 2019

Background: As of now, the impact of low back pain (LBP) and its chronic state, chronic low back pain (CLBP), on mental health-related quality of life (HRQOL) has never been investigated among police officers. The present investigation aims at studying this relationship using a biopsychosocial model. Methods: Between May and October 2014, a Web-based cross-sectional study was conducted among Quebec police officers (Quebec, Canada). Mental HRQOL was measured using the role emotional (RE) and the mental health (MH) domains of the SF-12v2 Health Survey. The impact of CLBP on mental HRQOL (as opposed to acute/subacute LBP or no LBP) was studied with a multivariate linear regression model. Results: Of the 3,589 police officers who participated in the study, 1,013 (28.4%) reported CLBP. The mean age of respondents was $38.5{\pm}8.7years$, and 32.0% were females. The RE (44.1/100) and MH (49.0/100) mean scores of the CLBP group were comparable with the scores found in populations suffering from cancer or heart diseases. Compared to officers without LBP, the presence of CLBP was significantly associated with lower RE (${\beta}$: -0.068; p = 0.003) and MH (${\beta}$: -0.062; p = 0.002) scores. These relationships were not found in the acute/subacute LBP group. Conclusion: Our results underscore how frequent CLBP is among police officers and how burdensome it is. Considering the importance of good physical and mental health for this occupational population, police organizations should be aware of this issue and contribute to the efforts toward CLBP prevention and management in the workplace.

• Particle and aerosol research
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• v.17 no.4
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• pp.81-89
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• 2021

Understanding particle-laden flow around cylindrical bodies is essential for the better design of various applications such as filters. In this study, laminar flows around two tandem cylinders and the motions of particles in the flow are numerically investigated at low Reynolds numbers. We aim to reveal the effects of the spacing between cylinders, Reynolds number and particle Stokes number on the characteristics of particle trajectories. When the cylinders are placed close, the unsteady flow inside the inter-cylinder gap at Re = 100 shows a considerable modification. However, the steady recirculation flow in the wake at Re = 10 and 40 shows an insignificant change. The change in the flow structure leads to the variation of particle dispersion pattern, particularly of small Stokes number particles. However, the dispersion of particles with a large Stokes number is hardly affected by the flow structure. As a result, few particles are observed in the cylinder gap regardless of the cylinder spacing and the Reynolds number. The deposition efficiency of the upstream cylinder shows no difference from that of a single cylinder, increasing as the Stokes number increases. However, the deposition on the downstream cylinder is found only at Re = 100 with large spacing. At this time, the deposition efficiency is generally small compared to that of an upstream cylinder, and the deposition location is also changed with no deposited particles near the stagnation point.

• The Korean Journal of Nuclear Medicine
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• v.36 no.3
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• pp.195-202
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• 2002

Purpose: For clinical application of beta-emitter labeled antibody, high specific activity is imporiant. Carrier-free $^{188}Re$ from $^{188}W/^{188}Re$ generator is an ideal radionuclide for this purpose. However, low stability of $^{188}Re$ labeled antibody, especially in high specific activity, due to radiolytic decomposition by high energy (2.1 MeV) beta ray was problem. We studied the stability of $^{188}Re$ labeled antibody, and stabilizing effect of several stabilizers. Materials and Methods: Pre-reduced monoclonal antibody (CEA79.4) was labeled with $^{188}Re$ by incubating with generator-eluted $^{188}Re-perrhenate$ in the presence of stannous tartrate for 2 hr at room temperature. Radiochemical purity of each preparation was determined by chromatography. Human serum albumin was added to the labeled antibodies (2%). Stability of $^{188}Re-CEA79.4$ was investigated in the presence of ascorbic acid, ethanol, of Tween 80 as stabilizing agents. Results: Labeling efficiencies were $88{\pm}4%\;(n=12)$. Specific activities of $1.25{\sim}4.77MBq/{\mu}g$ were obtained. If stored after purging with $N_2$, all the preparations were stable for 10 hr. However, stability decreased in the presence of air. Perrhenate and $^{188}Re-tartrate$ was major impurity in declined preparation. colloid-formation was not a significant problem in all cases. Addition of ascorbic acid stabilized the labeled antibodies either under $N_2$ or under air by reducing the formation of perrhenate. Conclusion: High specific activity $^{188}Re$ labeled antibody is unstable, especially, in the presence of oxygen. Addition of ascorbic acid increased the stability.

• Food Science and Preservation
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• v.23 no.1
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• pp.97-103
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• 2016

The antioxidant and digestive enzyme inhibitory effects of Eisenia bicyclis extracted by various extraction methods (RE, reflux extraction; SE, ultrasonification extraction; AE, autoclave extraction; LE, low-temperature high-pressure extraction) were investigated. The extraction yield (55.21%) and the laminarin (39.03%), fucoidan (24.75%), total polyphenol (115.68 mg GAE/g) and flavonoid (36.67 mg RHE/g) contents of AE were higher than those in other methods. The DPPH radical (86.60%, 500 mg%), ABTS radical (58.56%, 25 mg%), nitrite (86.38%, 100 mg%) scavenging activities of the Eisenia bicyclis extracted by AE were higher than those of Eisenia bicyclis extracted by other methods. The ABTS radical and nitrite scavenging activities were above 98% in all tested Eisenia bicyclis extracts and these activities were dependent on its concentration. The inhibitory effects of AE against amylase (50 mg%) and ${\alpha}$-glucosidase (5 mg%) were 64.76% and 86.71%, respectively. The AE showed the best inhibitory effect of Eisenia bicyclis extracts (50 mg%) against trypsin (24.37%) and ${\alpha}$-chymotrypsin (49.05%), respectively. These results suggest that Eisenia bicyclis extracted by AE can be used as a bioactive and functional material in the food industry.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.15-21
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• 2019

The worm reducer is capable of quadrature power transmission when the shafts are disposed at right angles to each other. Since a large reduction ratio can be obtained of up to approximately 1/100 and a sliding movement is performed during operation compared with other gears, the noise and vibration are small, and there is the advantage that reverse rotation can be prevented. On the other hand, severe wear and damage are displayed on the gear and worm tooth surface, and many defects, such as intense heat generation of the reducer, occur. In the reducer case, the four-piece casing method was selected to solve the problems of heat generation, transmission efficiency, and assemblability. In this paper, we analyzed the problems of the worm and worm wheel (the core parts of a 5-Ton worm reducer) and casing through these methods and researched how to solve them.