• Proceedings of the KWS Conference
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• 2005.11a
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• pp.55-57
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• 2005

In this study, modeling of the CD stud welding system was conducted considering mechanical and electrical components. The electrical components such as arc resistance, cable resistance, capacitance, internal resistance and cable inductance were found to affect the output waveform significantly. The calculated results showed food agreements with the experiment results within 20% error. The main defect of CD stud welding with 1010 steel stud and SS400 steel plate was the void trapped between stud and base metal. The effect of the spring force and stud tip size on void formation was investigated.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.3
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• pp.331-335
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• 2013

This study investigated the relationship between drinking and health factors including vaso-aging degree, stress index, stress resistance, fatigue and activity of autonomic nerve system etc. The subjects were 20,925 persons who had received health examination by Korean Medicine and submitted questionnaires about drinking history, for 8 months from March to November. The vaso-aging degree were measured by APG (Accelerated Photoplethysmograph). The stress index and resistance, fatigue and activity of autonomic nerve system were measured by HRV (Heart Rate Variability). We analyzed the relationship between drinking and various variables by chi-square test with SPSS ver. 19.0. Regarding the relationship between drinking and vaso-aging degree, there was significant differences(p<0.05). But regarding the relationship between drinking and the other factors, there were no statistically differences. This study suggests that the vaso-aging degree is affected by drinking alcohol.

• Journal of Korea Foundry Society
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• v.27 no.2
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• pp.72-76
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• 2007

Contact materials are widely used as electrical parts. Ag-Cd alloy has a good wear resistance and stable contact resistance. But the Cd exists as coarse oxide in alloy so it have an effect on mechanical properties badly. Moreover, the Cd is an injury material to environment. Nowadays, the use of Cd is strictly restricted. Because of these disadvantage, Ag-Sn-In alloy has been developed. In Ag-Sn-In alloy, the Sn : In ratio affects the internal oxidation properties, such as the formation of the oxide layer on the surface. In this work, we changed and optimized the Sn : In ratio variety for good internal oxidation properties. We have shown that a internal oxidation process did not fully completed when the Sn : In ratio is over 4 : 1 because of the Sn oxide layer at surface. The increase of In decelerates the formation of Sn oxide layer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7139-7142
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• 2015

Background: Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer related death overall. The role of insulin resistance in the development of HCC associated with chronic HCV infection has not been established. Resistin is a polypeptide hormone belonging to the adipokine family which could contribute to tumorigenesis and angiogenesis. Our aim was to study serum resistin and insulin resistance as risk factors for HCC in HCV cirrhotic patients. Materials and Methods: This prospective case controlled study included 100 patients with HCV related liver cirrhosis and HCC, 100 patients with HCV related liver cirrhosis without HCC and 50 apparently healthy participants as controls. For all subjects, liver profile, serologic markers for viral hepatitis, lipid profile, alpha-fetoprotein level (AFP), homeostasis model assessment (HOMA) were examined along with resistin. Results: HCC patients had higher mean values of HOMA-IR and resistin than cirrhotic patients and the control subjects (p<0.01). HOMA and resistin were considered independent risk factors in development of HCC, those patients with resistin > 12 ng/ml and HOMA > 4 being 1.6 times more likely to have HCC. Conclusions: HOMA and serum resistin allow for early identification of patients with cirrhosiswho are at substantially increased risk of HCC. Recommendation: HOMA and serum resistin could represent novel markers to identify HCV cirrhotic patients at greater risk of development of HCC.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1584-1589
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• 2008

Although resistance of Helicobacter pylori to clarithromycin is a major cause of failure of eradication therapies, little information is available regarding gene mutations of clarithromycin-resistant primary and secondary H. pylori isolates in Korea. In the present study, we examined gene mutations of H. pylori 238 rRNA responsible for resistance to clarithromycin. DNA sequences of the 238 rRNA gene in 21 primary clarithromycin-resistant and 64 secondary clarithromycin-resistant strains were determined by PCR amplification and nucleotide sequence analyses. Two mutations of the 238 rRNA gene, A2143G and T2182C, were observed in primary clarithromycin-resistant isolates. In secondary isolates, dual mutation of A2143G+T2182C was frequently observed. In addition, A2143G+T2182C+ T2190C, A2143G+T2182C+C2195T, and A2143G+T2182C+A2223G were observed in secondary isolates. Furthermore, macrolide binding was tested on purified ribosomes isolated from T2182C or A2143C mutant strains with $[^{14}C]$erythromycin. Erythromycin binding increased in a dose-dependent manner for the susceptible strain but not for the mutant strains. These results indicate that secondary isolates show a greater variety of 238 rRNA gene mutation types than primary isolates, and triple mutations of secondary isolates are associated with A2143G+T2182C in H. pylori isolated from Korean patients.

• Tuberculosis and Respiratory Diseases
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• v.81 no.3
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• pp.241-246
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• 2018

Background: The "Tuberculosis Relief Belt Supporting Project (Tuberculosis Patient Management Project for Poverty Groups)" is a national program for socioeconomically vulnerable tuberculosis (TB) patients. We sought to evaluate the clinical and socioeconomic characteristics of poverty-stricken TB patients, and determined the need for relief. Methods: We examined in-patients with TB, who were supported by this project at the National Medical Center from 2014 to 2015. We retrospectively investigated the patients' socioeconomic status, clinical characteristics, and project expenditures. Results: Fifty-eight patients were enrolled. Among 55 patients with known income status, 24 (43.6%) had no income. Most patients (80%) lived alone. A total of 48 patients (82.8%) had more than one underlying disease. More than half of the enrolled patients (30 patients, 51.7%) had smear-positive TB. Cavitary disease was found in 38 patients (65.5%). Among the 38 patients with known resistance status, 19 (50%) had drug-resistant TB. In terms of disease severity, 96.6% of the cases had moderate-to-severe disease. A total of 14 patients (26.4%) died during treatment. Nursing expenses were supported for 12 patients (20.7%), with patient transportation costs reimbursed for 35 patients (60%). In terms of treatment expenses for 31 people (53.4%), 93.5% of them were supported by uninsured benefits. Conclusion: Underlying disease, infectivity, drug resistance, severity, and death occurred frequently in socioeconomically vulnerable patients with TB. Many uninsured treatment costs were not supported by the current government TB programs, and the "Tuberculosis Relief Belt Supporting Project" compensated for these limitations.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.14-21
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• 1996

Objectives: Although outbreak of MDR Tb has been a recent problem in western countries, it has been a longstanding problem in Korea. The poor outcome of MDR Tb is mainly due to poor compliance, high rate of side reaction of secondary drugs, and limitation in number of available drugs. Thus, to improve the outcome of MDR Tb, it is crucial to make individualized adequate prescription based on the knowledge of the patterns of resistance to each drugs in the community as well as the natural history. The purpose of present study is to evaluate the clinical features of Korean MDR Tb patients including patterns of drug resistance and success rate of treatment which was prescribed according to the sensitivity tests. Methods: Retroscpective analysis of 71 Korean patients with MDR Tb was made. All strains isolated from patients showed resistence to at least two first line drugs. Patients profile, previous treatment history, patterns of drug resistance, outcome of treatment was analysed. Initial treatment regimen was selected according to the previous treatment history and was modified according to the sensitivity reports. The regimen was composed to include at least 4 sensitive drugs when possible. Results: The patients showed resistance to 4.1 drugs on average. 90% of them were resistant to INH and RFP. Among 71 patients, 35 patients(49%) had cavitary lesions in CXR. Treatment outcome was analysed in 55 patients. 35 patients(67%) were improved after treatment and 18 patients(33%) showed treatment failure. 5 patients showed primary resistance. Treatment outcome could be evaluated in 4 of them and all showed improvement after treatment. 14 patients(20%) had to change their regimens due to drug side effects. The most frequent side effect was elevation of liver enzymes(6 patients). Others included dizziness, hyperuricemia, tinnitus, skin rash, GI troubles. More than 50% of side effects developed within 3 months. In repeated drug sensitivity test, the concordance rate of resistance to INH was 100% and RFP 98%. EMB, PZA showed 80% concordance rate. But in the other drugs, the concordances were less than 50%. Operation was done in 5 patient - 1 patients as a adjunctive means of chemotherapy -. In that case, negative conversion of sputum AFB was done. Conclusion: 2/3 patients of multidrug-resistant tuberculosis were improved by appropriate prescription and regular medication suggesting that more aggressive management and monitoring is indicated in multidrug-resistant tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.79 no.4
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• pp.248-256
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• 2016

Somatic mutations that lead to hyperactivation of epidermal growth factor receptor (EGFR) signaling are detected in approximately 50% of lung adenocarcinoma in people from the Far East population and tyrosine kinase inhibitors are now the standard first line treatment for advanced disease. They have led to a doubling of progression-free survival and an increase in overall survival by more than 2 years. However, emergence of resistant clones has become the primary cause for treatment failure, and has created a new challenge in the daily management of patients with EGFR mutations. Identification of mechanisms leading to inhibitor resistance has led to new therapeutic modalities, some of which have now been adapted for patients with unsuccessful tyrosine kinase inhibitor treatment. In this review, we describe mechanisms of tyrosine kinase inhibitor resistance and the available strategies to overcoming resistance.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.416-418
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• 2008

Dye-sensitized solar cell using transparent conducting oxide as electrode has large resistance such as surface resistance, charge transportation impedance in counter electrode and electrolyte, impedance between each interface. Among that resistances, surface resistance of transparent conducting oxide is relatively large. So the change of transparency has a large effect on internal resistance of dye-sensitized solar cell. Consequently, that change cause to increase or decrease the conversion efficiency. We tried to reduce the surface resistance by laser-scribing. The active area is seperated from total transparent conducting oxide by Nd:YAG laser-scribing. As a result, we achieved the improvement of efficiency about 7% and 11% in case of $0.25cm^2$ and $1.00cm^2$ dye-sensitized solar cells.

• Tuberculosis and Respiratory Diseases
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• v.75 no.5
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• pp.188-198
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• 2013

Over the past decade, several kinase inhibitors have been approved based on their clinical benefit in cancer patients. Unfortunately, in many cases, patients develop resistance to these agents via secondary mutations and alternative mechanisms. To date, several major mechanisms of acquired resistance, such as secondary mutation of the epidermal growth factor receptor (EGFR) gene, amplification of the MET gene and overexpression of hepatocyte growth factor, have been reported. This review describes the recent findings on the mechanisms of primary and acquired resistance to EGFR tyrosine kinase inhibitors and acquired resistance to anaplastic lymphoma kinase inhibitors, primarily focusing on non-small cell lung carcinoma.