• 소성∙가공
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• 제13권1호
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• pp.72-77
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• 2004

An Fe-25Cr steel was oxidized in Ar atmosphere at 973K with and without applying external stress of 30∼35 MPa. A 0.1$\mu\textrm{m}$ thick $Cr_2O_3$ scales formed during pre-treatment in Ar atmosphere. Initiation of cracking on the oxide scales took place at grain boundaries during the end of second creep stage, in which cracks were found nearly perpendicular to the tensile directions. On the contrary, a scale developed in $N_2$-0.1%$SO_2$ displaced a poor adherence on the metal substrate. In this sample, a fast grown of scales was observed during creep deformation, and the strength of materials was much lower than in Ar. The creep strain rate of $1.5{\times}10^{-7}/s$ and $5.8{\times}10^{-7}/s$ was determined in Ar and in $N_2$-0.1%$SO_2$ under 30MPa, respectively.

• 셀메드
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• 제7권2호
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• pp.10.1-10.10
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• 2017

The Maasai community from Kenya is highly esteemed for their strong adherence to traditional cultures and ethno medicine. This is attributed to their age-old traditional mechanisms of passing down knowledge to the younger generation. Adoption to new socio-economic lifestyle and urbanization has been associated with development of diabetes, which has been reported among some indigenous pastoral communities in Kenya. Documentation of traditional methods of treatment and management of diabetes by the Maasai has not yet been reported, yet it is noteworthy. Thirty traditional healers from Narok County were purposively selected and interviewed about traditional knowledge of antidiabetic medicinal plants, parts used, preparation dosage and administration. A total of 14 antidiabetic plant species distributed within 13 genera and 12 families were identified and documented as herbal medicine used in the management of diabetes. The most highly cited plant species was Dovyalis abyssinica (20%), the plant family Flacourtiaceae and Rhamnaceae (2 plant species each) recorded the highest number of plant species while the most frequently used plant part was the roots (46%). Literature review revealed that some of the cited plants have known phytochemicals with antidiabetic activity; the study recommends further scientific investigation to validate their efficacy and safety.

• 한국가축번식학회지
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• 제14권2호
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• pp.115-124
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• 1990

These experiments were undertaken as a basic study to develop immunocontraceptive vaccine and to understand the role of zona pellucidae in early fertilization process by investigating the effect of monoclonal and polyclonal antibody to porcine zona pellucidae and polyclonal antibody to mouse zona pellucidae on the fertilization of porcine and mouse eggs in vitro. The results obtained in these experiments were summarized as follows : 1. Treatment of porcine and mouse eggs with undiluted anti-zona serum produced intense precipitation layer on the poricne and mouse zonae, respectively, thus resulting in the total inhibition of sperm adherence on surface of zona. 2. In vitro fertilization of eggs pre-treated with 0.3∼10% of various antibodies was examined, and resulting in that 5 and 10% of rabbit polyclonal antibodies to porcine zona inhibited completely both in vitro fertilization and polyspermy of porcine eggs while monoclonal to porcine zona and rabbit polyclonal antibody to mouse zona did not inhibit in vitro fertilization but monoclonal antibody reduced the rate of polyspermy compared to that of control group. Almost the same results were obtained in the study on the effect of anti-zona serum on in vitro fertilization of mouse eggs.

• Perspectives in Nursing Science
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• 제10권1호
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• pp.1-11
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• 2013

Purpose: Given the importance and impact of trust between nurse and pediatric patient on treatment adherence and nursing outcomes, this study was aimed to investigate how nurses perceive the trust between nurses themselves and children in a hospital setting using a qualitative research methodology. Methods: In depth interviews with 10 nurses working at pediatric units were conducted using semi-structured questionnaires, and data were analyzed using a thematic analysis. Results: Main themes were categorized as attributes of nurse-child trust and influencing factors. Attributes of trust can be divided into definition and characteristics of nurse-child trust. Nurses perceived nurse-child trust were not coercive, and changeable mutual relationship needing time and effort, and helpful for child's hospital adaptation and child's participation for care. There existed facilitating factors and interfering factors in developing nurse-child trust. Conclusion: The findings of this study would help nurses who are caring children in a hospital setting re-shape their points of views on 'trust between nurses and children' in day to day practice. It is also hoped that these results contribute to develop nursing guidelines on trust building with children in hospital in future.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 춘계학술발표회 초록집
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• pp.147-148
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• 2007

In this study, the technology to grow oriented nanotube thin film from dip-coated $TiO_2$ using hydrothermal method has been successfully developed. The effects of preparation parameters, such as reaction temperature, duration and post treatment conditions on the film morphologies and the adherence to the substrate, have been examined. A general formation mechanism of oriented titanate nanotube thin film is proposed in terms of the detailed observation of the products via two dimensional surface FESEM studies and HRTEM images. The overall formation of $TiO_2-based$ nanotube thin film can be summarized with three successive steps: (1) $TiO_2$ dissolving and amorphous $Na_2TiO_3$ deposition process; (2) layered $Na_2Ti_3O_7$ formation via spontaneous crystallization and rapid growth process; (3) formation of nanotube thin film via $Na_2Ti_3O_7$ splitting and multilayer scrolling process of (100) planes around the c axis of $Na_2Ti_3O_7$.

• 보건행정학회지
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• 제31권2호
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• pp.207-216
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• 2021

Background: Good patient experience is positively associated with adherence to treatment recommendations, better clinical effectiveness, and health outcomes. This study aims to find out the key factors affecting positive patient experience to improve the quality of care using nationally representative survey data. Methods: The data was collected from the 6th National Health Nutrition Survey in 2015. Four patient experience items were investigated for patients with visiting outpatient care over the past year. Positive patient experience was defined as a case of responding always or usually yes. The t-test, chi-square test, and multiple logistic regression were performed to determine the key factors affecting the outpatient experience. Results: More than 80% of the respondents reported their care experience as positive excluding doctor spending enough time during the consultation. Male, poor health status, and single/divorced, and the longer time interval between outpatient care visit and survey were found to be significantly correlated with negative care experiences in the multiple logistic regression. Patients who received outpatient care at the oriental medicine clinic had a positive experience compared to those received outpatient care at the general hospital. However, patient factors including age, income, job, and insurance type had no significant association with patient experience. Conclusion: Health care providers should prioritize patients who report negative patient experiences and implement management decisions to improve the patient experience.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.52.1-52.11
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• 2020

Objectives: Yttria-stabilized tetragonal phase zirconia has been used as a dental restorative material for over a decade. While it is still the strongest and toughest ceramic, its translucency remains as a significant drawback. To overcome this, stabilizing the translucency zirconia to a significant cubic crystalline phase by increasing the yttria content to more than 8 mol% (8YTZP). However, the biocompatibility of a high amount of yttria is still an important topic that needs to be investigated. Materials and Methods: Commercially available 8YTZP plates were used. To enhance cell adhesion, proliferation, and differentiation, the surface of the 8YTZP is sequentially polished with a SiC-coated abrasive paper and surface coating with type I collagen. Fibroblast-like cells L929 used for cell adherence and cell proliferation analysis, and mouse bone marrow-derived mesenchymal stem cells (BMSC) used for cell differentiation analysis. Results: The results revealed that all samples, regardless of the surface treatment, are hydrophilic and showed a strong affinity for water. Even the cell culture results indicate that simple surface polishing and coating can affect cellular behavior by enhancing cell adhesion and proliferation. Both L929 cells and BMSC were nicely adhered to and proliferated in all conditions. Conclusions: The results demonstrate the biocompatibility of the cubic phase zirconia with 8 mol% yttria and suggest that yttria with a higher zirconia content are not toxic to the cells, support a strong adhesion of cells on their surfaces, and promote cell proliferation and differentiation. All these confirm its potential use in tissue engineering.

• 대한의생명과학회지
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• 제29권4호
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• pp.280-286
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• 2023

In humic substances, fulvic acid (FA) is a subclass of diverse compounds known as humic substances, which are by-products of organic degradation from microorganisms. FA can suppress the proliferation of tumor cells. Despite numerous studies, the exact mechanism for the various effects of FA is not clearly understood. Based on results demonstrating anti-proliferation effects on human cancer, we investigated whether FA has similar effects on lung cancer in this study. Firstly, the anti-cancer effect of FA in pulmonary epithelial tumor cell lines (TC-1 cells) was examined by confirming its inhibitory effect on the cell proliferation of TC-1 cells. TC-1 cell proliferation was reduced by FA on a dose-dependent and time-dependent manner. After 24 hours of FA treatment, cell morphological changes such as cell volume decrease, non-adherence and increased number of apoptotic cells were clearly observed. In addition, FA induced a DNA ladder pattern by increased of DNA fragments in TC-1 cells. In the intracellular regulatory pathway by FA, we confirmed that FA induced the reduction of the anti-apoptotic protein, Bcl-2 protein levels. These results indicate that FA has anticancer effect by inducing intracellular apoptotic pathway. Further research on the mechanism of anticancer effects will be basic data for the development of potential anticancer drugs.

• 한국임상약학회지
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• 제26권1호
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• pp.24-32
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• 2016

Objective: The visually impaired have limited access to health care services and related information, and thus, they can have serious hurdles against properly taking medications. Despite that it is important to improve self-care ability of the visually impaired for correct medication use, there have been few studies investigating their needs for health care services in Korea, particularly focusing on proper medication usage. This study is to explore safety-related issues regarding mediation usage among the visually impaired based on in-depth interview. We particularly focus on any obstacles for safe use of medicines including experience on medication-related adverse effects in order to provide preliminary evidence for policy measures to improve proper medication use among the visually impaired. Methods: Study sample was visually impaired individuals who resided in Seoul area and were registered in the National Association of Visually Impaired. The association helped the process of recruiting the study participants. In-depth interview for each study participants was conducted. Each interview was recorded and later converted into a written script to extract core contents for the analysis. Results: The study participants comprised of three women (42.9%) and four men (57.1%). One was in his 20's, and there were four participants in 30's and two in 40's. Fully impaired participants were majority (5 out of 7). Limitation to physical access to health care providers and health information were the key factors to hamper safe medication utilization among the study participants. Difficulty reading medication information and may take the wrong medication or incorrect doses of medication, resulting in serious consequences, including overdose or inadequate treatment of health problems. Visually impaired patients report increased anxiety related to medication management and must rely on others to obtain necessary drug information. Pharmacists have a unique opportunity to pursue accurate medication adherence in this special population. This article reviews literature illustrating how severe medication mismanagement can occur in the visually impaired elderly and presents resources and solutions for pharmacists to take a larger role in adherence management in this population. Conclusion: The visually impaired had difficulties reading medication information and identifying medicines, and took incorrect doses of medications. Public support for safe medication use and medication management among the visually impaired is necessary.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.89-91
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• 2000

Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.