• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.77-77
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• 2017

Titanium and its alloys offer attractive properties in a variety of applications. These are widely used for the field of biomedical implants because of its good biocompatibility and high corrosion resistance. Titanium anodizing is often used in the metal finishing of products, especially those can be used in the medical devices with dense oxide surface. Based on SAE/AMS (Society of Automotive Engineers/Aerospace Material Specification) 2488D, it has the specification for industrial titanium anodizing that have three different types of titanium anodization as following: Type I is used as a coating for elevated temperature forming; Type II is used as an anti-galling coating without additional lubrication or as a pre-treatment for improving adherence of film lubricants; Type III is used as a treatment to produce a spectrum of surface colours on titanium. In this study, we have focused on Type II anodization for the medical (dental and orthopedic) application, the anodized surface was modified with gray color under alkaline electrolyte. The surface characteristics were analyzed with Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM), surface roughness, Vickers hardness, three point bending test, biocompatibility, and corrosion (potentiodynamic) test. The Ti-6Al-4V alloy was used for specimen, the anodizing procedure was conducted in alkaline solution (NaOH based, pH>13). Applied voltage was range between 20 V to 40 V until the ampere to be zero. As results, the surface characteristics of anodic oxide layer were analyzed with SEM, the dissecting layer was fabricated with FIB method prior to analyze surface. The surface roughness was measured by arithmetic mean deviation of the roughness profile (Ra). The Vickers hardness was obtained with Vickers hardness tester, indentation was repeated for 5 times on each sample, and the three point bending property was verified by yield load values. In order to determine the corrosion resistance for the corrosion rate, the potentiodynamic test was performed for each specimen. The biological safety assessment was analyzed by cytotoxic and pyrogen test. Through FIB feature of anodic surfaces, the thickness of oxide layer was 1.1 um. The surface roughness, Vickers hardness, bending yield, and corrosion resistance of the anodized specimen were shown higher value than those of non-treated specimen. Also we could verify that there was no significant issues from cytotoxicity and pyrogen test.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.83-89
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• 2006

Cellular functions are carried out by a concerted action of biochemical pathways whose components have genetic interactions. Abnormalities in the activity of the genes that constitute or modulate these pathways frequently have oncogenic implications. Therefore, identifying the upstream regulatory genes for major biochemical pathways and defining their roles in carcinogenesis can have important consequences in establishing an effective target-oriented antitumor strategy We have analyzed the gene expression profiles of human liver cancer samples using cDNA microarray chips enriched in liver and/or stomach-expressed cDNA elements, and identified groups of genes that can tell tumors from non-tumors or normal liver, or classify tumors according to clinical parameters such as tumor grade, age, and inflammation grade. We also set up a high-throughput cell-based assay system (cell chip) that can monitor the activity of major biochemical pathways through a reporter assay. Then, we applied the cell chip platform for the analysis of the HCC-associated genes discovered from transcriptome profiling, and found a number of cancer marker genes having a potential of modulating the activity of cancer-related biochemical pathways such as E2F, TCF, p53, Stat, Smad, AP-1, c-Myc, HIF and NF-kB. Some of these marker genes were previously blown to modulate these pathways, while most of the others not. Upon a fast-track phenotype analysis, a subset of the genes showed increased colony forming abilities in soft agar and altered cell morphology or adherence characteristics in the presence of purified matrix proteins. We are currently analyzing these selected marker genes in more detail for their effects on various biological Processes and for Possible clinical roles in liver cancer development.

• Korean Journal of Community Nutrition
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• v.24 no.6
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• pp.525-534
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• 2019

Objectives: Reduced glucose utilization in the main parts of the brain involved in memory is a major cause of Alzheimer's disease, in which ketone bodies are used as the only and effective alternative energy source of glucose. This study examined the effects of a low-carbohydrate and high-fat (LCHF) diet supplemented with a ketogenic nutrition drink on cognitive function and physical activity in the elderly at high risk for dementia. Methods: The participants of this study were 28 healthy elderly aged 60-91 years showing a high risk factor of dementia or whose Korean Mini-Mental State Examination (K-MMSE) score was less than 24 points. Over 3 weeks, the case group was given an LCHF diet with nutrition drinks consisting of a ketone/non-ketone ratio of 1.73:1, whereas the control group consumed well-balanced nutrition drinks while maintaining a normal diet. After 3 weeks, K-MMSE, body composition, urine ketone bodies, and physical ability were all evaluated. Results: Urine ketone bodies of all case group subjects were positive, and K-MMSE score was significantly elevated in the case group only (p=0.021). Weight and BMI were elevated in the control group only (p<0.05). Grip strength was elevated in all subjects (p<0.01), and measurements of gait speed and one leg balance were improved only in the case group (p<0.05). Conclusions: We suggest that adherence to the LCHF diet supplemented with a ketogenic drink could possibly influence cognitive and physical function in the elderly with a high risk factor for dementia. Further, we confirmed the applicability of this dietary intervention in the elderly based on its lack of any side effects or changes in nutritional status.

• Korean Journal of Psychosomatic Medicine
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• v.29 no.2
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• pp.86-94
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• 2021

Objectives : The risk of weight gain is high when using antipsychotic drugs, and the prevalence of obesity in people with mental illness is high. Obesity management in psychiatric patients is important because obesity causes various complications and lowers treatment adherence and quality of life. Methods : In this review, we summarized the management strategies for obesity that can occur when using antipsychotic drugs through a web search. Results : Evaluate obesity-related risk factors and related indicators from the beginning of treatment, and conduct regular monitoring. If an antipsychotic drug is used and obesity is induced, a change to a drug with a low metabolic risk may be attempted. Sufficient interventions are also needed on the need to manage obesity, a healthy diet, and exercises in patients and their families. If weight loss is not achieved and obesity-related complications are associated, the use of anti-obesity drugs may be considered. Pharmacological treatment approaches should be carefully considered. Conclusions : Non-pharmacological and pharmacological therapies can be applied to manage weight gain and obesity caused by the use of antipsychotic drugs. When using anti-obesity drugs, the characteristics of mental disorders, drug safety, and drug interactions should be considered.

• Informatization Policy
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• v.26 no.1
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• pp.83-105
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• 2019

The purpose of this study is to analyze the domestic and overseas laws and regulators' decisions related to zero-rating (ZR) practices through a comparative approach and to support development of the ex-post regulation. Although most countries are adopting ex-post regulatory approaches toward the globally increasing ZR practices, there is no uniform standards or an approach to consider when deciding whether to allow mobile ISPs' zero-rating practices in the market. However, in recent years, some countries have been improving their policy transparency with respect to ZR through enacting and amending relevant laws as well as making trial decisions. The comparative analysis shows that each country investigates restriction of the user choice and ISPs' adherence to the obligation of non-discrimination in order to judge whether the user benefits are damaged by the ZR practices. It also investigates ISP-CP's market positioning and ISP's vertical integration for profit squeeze to find out whether they harm fair competition with ZR practices in the mobile ecosystem. Based on the results of the comparative analysis, we suggest the desirable ZR regulatory directions under the domestic legislative status.

• Pediatric Infection and Vaccine
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• v.14 no.2
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• pp.162-170
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• 2007

Purpose : While cases of vancomycin-resistant enterococci (VRE) have increasingly been reported worldwide since it was first reported in the late 1980s, there have been few systemic studies on the pediatric population. The purpose of this study is to contribute to the planning of VRE prevention by investigating the prevalence, risk factors and transmission of VRE infection. Methods : We studied 230 patients under age 15 years who were isolated VRE between January 2001 and December 2006 retrospectively. The patients were classified into the intensive care unit (ICU) and the non-ICU groups. We reviewed the procedures before VRE detection as well as antibiotic sensitivity of detected organisms. Results : The number of VRE-isolation cases was higher in the ICU group than the non-ICU group. Instances of VRE-isolation were also more prevalent in patients who underwent operations or active procedures while taking 3rd-generation cephalosporins or glycopeptides. Almost all antibiotics except tetracycline were resistant to VRE. The proportion of 3rd-generation cephalosporin use was higher than those of any other antibiotics before VRE detection. Additionally, the use of 3rd-generation cephalosporins has increased annually, but that of glycopeptides had decreased in 2006. Also, the rates of VRE isolation have been increasing since 1998. Conclusion : VRE infection is increasing in pediatric population. Strict adherence to appropriate infection control guidelines for the prevention of VRE transmission in hospitals, and tracking of VRE colonization through active surveillance in high risk units are recommended.

• Korean Journal of Health Education and Promotion
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• v.25 no.5
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• pp.79-92
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• 2008

Purpose: Recommendation for regular Pap test in the past 3 years as a cue to action affects on an increased likelihood of receiving a cervical cancer screening in that period. This study performed to estimate the association with healthcare access, healthcare provider status, and physician recommendation for Pap test in the past 3 years among Korean American women. Method: Korean Health survey was carried out in 2002. These population-based telephone surveys were conducted with Korean American women who resided in Alameda and Santa Clara Counties, California (n=865). We preformed multiple logistic regression analyses to estimate predictors of physician recommendation for Pap test by SAS 8.2. Results: Korean women in two California Counties were 37.9% who received physician recommendation for Pap test in the past 3 years. The predictors on physician recommendation for Pap test in the past 3 years were health insurance coverage, visiting number to doctor in the past year, and healthcare provider status. For healthcare access, no matter who had enrolled in public or private health insurances, the women were more likely to get the recommendation for Pap test from their regular healthcare provider. Particularly, for ethnicity of healthcare provider, the women were more likely to get the recommendation for Pap test from non-Korean female doctors (OR=6.21, 95% CI=2.63, 14.66), Korean male doctors (OR=2.19, 95% CI=1.30, 3.68), and non-Korean male doctors (OR=2.07, 95% CI=1.15, 3.71). Conclusion: (삭제) Effect of healthcare access and healthcare provider status on recommendation for Pap test among Korean American women in two California Counties would contribute to our understanding of developing strategies to promote adherence of Pap test and reduce morbidity and mortality far cervical cancer among Korean American women in the U.S.