• Korean Journal of Metals and Materials
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• v.49 no.2
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• pp.128-136
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• 2011

Equal channel angular pressing (ECAP) with intermediate heat treatment was employed to optimize the strength of Cu-15 wt.%Ag. Changes in microstructure, electrical properties and mechanical properties were studied as a function of pressing methods and heat treatment. ECAPed Cu-15wt.%Ag exhibited ultrafine-grained microstructures with the shape and distribution of Ag-rich lamellae dependent on the processing routes. For route A in which the sample was pressed without rotation between each pass, the initial dendrites of Ag-rich phase were elongated along the shear direction and developed into elongated filaments. For route C in which the sample was rotated by 180 degree after each pass, the morphology of initial dendrites of Ag-rich phase was not much modified and the networked structure remained even after 8 passes of ECAP. For route Bc in which the sample was rotated by 90 degree after each pass, the initial dendrites became finer by fragmentation with no pronounced change of the shape and distribution of Ag-rich lamellae. The strength of Cu-15wt.%Ag ECAPed using route Bc was found to be greater than those ECAPed using route A, suggesting that the substructural strengthening is more effective in strengthening than the interface strengthening.

• Biomolecules & Therapeutics
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• v.30 no.1
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• pp.28-37
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• 2022

Treatment options for patients with chronic kidney disease (CKD) are currently limited; therefore, there has been significant interest in applying mesenchymal stem/stromal cell (MSC)-based therapy to treat CKD. However, MSCs harvested from CKD patients tend to show diminished viability and proliferation due to sustained exposure to uremic toxins in the CKD environment, which limits their utility for cell therapy. The application of melatonin has been demonstrated to improve the therapeutic efficacy of MSCs derived from and engrafted to tissues in patients suffering from CKD, although the underlying biological mechanism has not been elucidated. In this study, we observed overexpression of hexokinase-2 (HK2) in serum samples of CKD patients and MSCs harvested from an adenine-fed CKD mouse model (CKD-mMSCs). HK2 upregulation led to increased production levels of methylglyoxal (MG), a toxic metabolic intermediate of abnormal glycolytic processes. The overabundance of HK2 and MG was associated with impaired mitochondrial function and low cell proliferation in CKD-mMSCs. Melatonin treatment inhibited the increases in HK2 and MG levels, and further improved mitochondrial function, glycolytic metabolism, and cell proliferation. Our findings suggest that identifying and characterizing metabolic regulators such as HK2 in CKD may improve the efficacy of MSCs for treating CKD and other kidney disorders.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.590-597
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• 2003

Processing and smelting of copper containing sulphide concentrates result in the accumulation of impurities into various process streams. All primary copper smelters and refineries around the world produce significant amounts of slag, dust, sludge, residues and others, which contain copper and precious metals. The recovery of these valuable metals is essential to the overall economics of the smelting process. Physical, chemical and mineralogical characterization of particular slag and Cottrell dusts from primary smelters and $Dor\'{e}$ furnace (TBRC) slag and Pressure Leached Anode slimes from a copper refinery have been carried out to understand the basic behind the recovery processes. Various process options have been evaluated and adapted for the treatment of slag from different smelting furnaces and Cottrell dusts as well as the intermediate products from copper refineries. Besides the hydro- or pyro-metallurgical treatments, the above mentioned physical separation options such as magnetic, gravity separation, flotation and precipitation flotation processes have been successfully identified and adapted as the possible process options to produce a Cu-rich or precious metal-rich concentrates for in-house recycling and other valued by-product for further treatment. The results of laboratory, pilot plant and production operations are presented, and incorporation of several alternative flowsheet is discussed in this paper.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.156-162
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• 2023

The purpose of this study was to examine the effects of peer scaffolding on the writing fluency of English language learners. This study was intended to confirm that peer scaffolding in English as a foreign language (EFL) writing classes can improve students' English proficiency. An analysis of 20 EFL learners studying at a university in Gyeonggi Province was conducted based on the English Proficiency Test. In this study, 20 intermediate learners with similar proficiency levels were included in the sample. Randomly, 10 students were designated as members of the control group, and 10 students were designated as members of the experimental group. In the experimental group, students practiced essay writing, while a skilled student provided scaffolding for a less skilled student. A variety of tools were used to gather data, including tests, questionnaires, and interviews Statistical analyses of quantitative data were conducted using t-tests for independent samples, whereas analyses of qualitative data were conducted based on themes. Pre-test results indicated a significant value of sig. =0.87, which was higher than α = 0.05. According to the results of this study, the writing performance of both experimental and control groups of students was equal and homogeneous prior to treatment. However, there were significant differences between the writing of students in the two groups after the completion of the program. Due to the post-test analysis of the writing test, the test resulted in a sig. =0 .043, a value lower than α = 0.05. As a result, the experimental group participants showed a marked improvement in their writing abilities after treatment.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2003.10a
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• pp.22-34
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• 2003

Processing and smelting of copper containing sulphide concentrates result in the accumulation of impurities into various process streams. All primary copper smelters and refineries around the world produce significant amounts of slag, dust, sludge, residues and others, which contain copper and precious metals. The recovery of these valuable metals is essential to the overall economics of the smelting process. Physical, chemical and mineralogical characterization of particular slag and Cottrell dusts from primary smelters and Dore furnace (TBRC) slag and Pressure Leached Anode slimes from a copper refinery have been carried out to understand the basic behind the recovery processes. Various process options have been evaluated and adapted for the treatment of slag from different smelting furnaces and Cottrell dusts as well as the intermediate products from copper refineries. Besides the hydro- or pyre-metallurgical treatments, the above mentioned physical separation options such as magnetic, gravity separation, flotation and precipitation flotation processes have been successfully identified and adapted as the possible process options to produce a Cu-rich or precious metal-rich concentrates for in-house recycling and other valued by-product for further treatment. The results of laboratory, pilot plant and production operations are presented, and incorporation of several alternative flowsheet is discussed in this paper.

• Journal of Digestive Cancer Research
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• v.12 no.1
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• pp.23-30
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• 2024

Borderline resectable pancreatic cancer, an intermediate stage between a completely resectable state and an unresectable state, requires a multidisciplinary treatment approach. This study aimed to elucidate the main characteristics and recent research trends regarding borderline resectable pancreatic cancer to gain further insights into them. Data from published papers about borderline resectable pancreatic cancer were collected from Web of Science (2014-2023) for the analysis. This study included 355 papers; data on major countries, publishing organizations, and keywords were collected and analyzed. Furthermore, R studio and VOSviewer were used for the qualitative and quantitative analyses of keywords. Publication of papers on borderline resectable pancreatic cancer was observed to be increasing annually by 12.8%, with the United States and Japan being the main publishing countries. In 2014, keywords related to surgery and chemotherapy were dominant; however, a shift toward more integrative approaches, such as neoadjuvant therapy, was observed over time. This study demonstrates rapidly evolving trends and paradigm changes in the research and management of borderline resectable pancreatic cancer. Thus, the results of this study are expected to contribute to establishing future research strategies and improving patient treatment outcomes.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.131-140
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• 2008

The application of magnetic ion exchange resin($MIEX^{(R)}$) is effective for natural organic matter(NOM) removal and for control of the formation of disinfection byproducts(DBPs). NOM removal is also enhanced by adding $MIEX^{(R)}$ with coagulant such as polyaluminium chloride(PACl) in conventional drinking water treatment systems. In the application of $MIEX^{(R)}$, it is important to understand changes of NOM characteristics such as hydrophobicity and molecular weight distributions with $MIEX^{(R)}$ or $MIEX^{(R)}$+coagulant treatment.To observe characteristics of NOM by treatment with $MIEX^{(R)}$ or $MIEX^{(R)}$+coagulant, four major drinking water sources were employed. Results showed that the addition of $MIEX^{(R)}$ to coagulation significantly reduced the amount of coagulant required for the optimum removal of dissolved organic matter(DOC) and turbidity in the all four waters. The DOC removal was also increased approximately 20%, compared to coagulant treatment alone. The process with $MIEX^{(R)}$ and coagulant showed that complementary removal of hydrophobic and hydrophilic fraction of DOC. The combined processes preferentially removed the fractions of intermediate (3,000-10,000 Da) and low (< 500 Da) molecular weight. The microfiltration test showed that membrane cake resistance was decreased for waters with flocs from $MIEX^{(R)}$+coagulant. A porous layer was formed to $MIEX^{(R)}$ on the membrane surface and the layer consequently inhibited settling of coagulant flocs, which could act on a foulant.

• Clinical and Experimental Pediatrics
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• v.56 no.7
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• pp.291-297
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• 2013

Purpose: The aim of this study was to investigate prophylactic treatment effects in Korean patients with severe hemophilia A. Methods: A prospective study of 32 severe hemophilia A patients was conducted with the approval of the Institutional Review Board at the Eulji University Hospital. Two patients received primary prophylaxis; whereas, the other 30 patients were divided into 2 groups-secondary prophylaxis (n=15) and on-demand (n=15)-on the basis of their consent for secondary prophylaxis. A 20-25 IU/kg dose of factor VIII concentrate was administered to the primary and secondary prophylaxis group patients every 3 days for 1 year. The prophylactic effect was evaluated by observing changes in the Pettersson scores, annual number of total and joint bleeds, and factor VIII consumption for 1 year. Results: No moderate or severe bleeding was observed, and the Pettersson scores remained unchanged during the prophylaxis period in the patients who received primary prophylactic treatment. After the treatment was changed from on-demand to secondary prophylaxis, the annual number of total and joint bleeds in the secondary prophylaxis group decreased by $64.4%{\pm}13.0%$ and $70.0%{\pm}15.2%$, respectively. The average increase in Pettersson scores within 1 year was $0.5{\pm}0.8$ and $1.3{\pm}1.1$ in the secondary prophylaxis and on-demand groups, respectively. Prophylactic effects were also observed in patients >17 years who had nearly the same initial Pettersson scores. Conclusion: Intermediate-dose prophylactic treatment may delay hemarthropathy progression and prevent its occurrence in Korean severe hemophilia A patients.

• Tuberculosis and Respiratory Diseases
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• v.78 no.3
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• pp.227-231
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• 2015

Background: Diagnostic methods for pulmonary tuberculosis (TB) have recently advanced. The aim of this study was to evaluate the changes in TB diagnostic tests that prompted the initiation of anti-TB treatment over time in South Korea, an industrialized country with an intermediate TB burden. Methods: Patients diagnosed with pulmonary TB in the first halves of 2005 and 2013 at a tertiary referral hospital were included. Diagnostic methods that prompted the initiation of anti-TB treatment were compared between the 2 groups of patients. Results: A greater proportion of patients were diagnosed with pulmonary TB using bronchoscopy in 2013 than in 2005 (26.7% vs. 6.6%, respectively; p<0.001), while the proportion of patients clinically diagnosed with pulmonary TB was lower in 2013 than in 2005 (24.7% vs. 49.0%, respectively; p<0.001). Additionally, more patients started anti-TB treatment based on positive polymerase chain reaction (PCR) results for Mycobacterium tuberculosis DNA in 2013 than in 2005 (47.3% vs. 7.9%, respectively; p<0.001). Conclusion: The initiation of treatment for pulmonary TB in South Korea has become more frequently based on PCR and the use of bronchoscopic specimens.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7555-7559
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• 2015

Background: CML includes 30% of all leukemias, and occurs from childhood to old age. The present study was a retrospective analysis of chronic phase CML patients registered to a Hematology Clinic in Kermanshah, Iran, with checking of treatment options. Materials and Methods: Between 2002 and 2014, 85 CML patients referred to our hematology clinic were enrolled in our study. We surveyed age, sex, B-symptoms, splenomegaly, Sokal score, Hasford score, treatment and survival in all patients. Philadelphia chromosome analysis was conducted for each patient by conventional cytogenetics. We compared treatment in the patients with three drugs, imatinib, hydroxyurea (HU) and interferon alpha (IFN-${\alpha}$). Results: The mean age of the patients at diagnosis was $47.5{\pm}14.5years$ (range, 23-82 years), with 43 (50.6%) being male. Some 13 (15.3%) were referred to our clinic for the first time with B-symptoms and 44 patients (51.8%) had splenomegaly. The Sokal score for 77 (90.6%) was low, 4 (4.7%) was intermediate and 4(4.7%) was high, but Hasford (Euro) scores for all patients were low. The 5-year survival rate for treated patients with imatinib, imatinib plus HU and imatinib plus HU plus IFN-${\alpha}$ was 90.5%, 81.1% and 55.6%, respectively Conclusions: The results show that imatinib therapy alone provides better survival in CML patients compared to HU or IFN-${\alpha}$. Combinations of IFN-${\alpha}$ and/or HU with imatinib probably reduce survival.