• Journal of Astronomy and Space Sciences
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• v.36 no.1
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• pp.21-33
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• 2019

This paper focuses on the interpretation of radiation fluxes from active galactic nuclei. The advantage of positron annihilation spectroscopy over other methods of spectral diagnostics of active galactic nuclei (therefore AGN) is demonstrated. A relationship between regular and random components in both bolometric and spectral composition of fluxes of quanta and particles generated in AGN is found. We consider their diffuse component separately and also detect radiative feedback after the passage of high-velocity cosmic rays and hard quanta through gas-and-dust aggregates surrounding massive black holes in AGN. The motion of relativistic positrons and electrons in such complex systems produces secondary radiation throughout the whole investigated region of active galactic nuclei in form of cylinder with radius R= 400-1000 pc and height H=200-400 pc, thus causing their visible luminescence across all spectral bands. We obtain radiation and electron energy distribution functions depending on the spatial distribution of the investigated bulk of matter in AGN. Radiation luminescence of the non-central part of AGN is a response to the effects of particles and quanta falling from its center created by atoms, molecules and dust of its diffuse component. The cross-sections for the single-photon annihilation of positrons of different energies with atoms in these active galactic nuclei are determined. For the first time we use the data on the change in chemical composition due to spallation reactions induced by high-energy particles. We establish or define more accurately how the energies of the incident positron, emitted ${\gamma}-quantum$ and recoiling nucleus correlate with the atomic number and weight of the target nucleus. For light elements, we provide detailed tables of all indicated parameters. A new criterion is proposed, based on the use of the ratio of the fluxes of ${\gamma}-quanta$ formed in one- and two-photon annihilation of positrons in a diffuse medium. It is concluded that, as is the case in young supernova remnants, the two-photon annihilation tends to occur in solid-state grains as a result of active loss of kinetic energy of positrons due to ionisation down to thermal energy of free electrons. The single-photon annihilation of positrons manifests itself in the gas component of active galactic nuclei. Such annihilation occurs as interaction between positrons and K-shell electrons; hence, it is suitable for identification of the chemical state of substances comprising the gas component of the investigated media. Specific physical media producing high fluxes of positrons are discussed; it allowed a significant reduction in the number of reaction channels generating positrons. We estimate the brightness distribution in the ${\gamma}-ray$ spectra of the gas-and-dust media through which positron fluxes travel with the energy range similar to that recorded by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) research module. Based on the results of our calculations, we analyse the reasons for such a high power of positrons to penetrate through gas-and-dust aggregates. The energy loss of positrons by ionisation is compared to the production of secondary positrons by high-energy cosmic rays in order to determine the depth of their penetration into gas-and-dust aggregations clustered in active galactic nuclei. The relationship between the energy of ${\gamma}-quanta$ emitted upon the single-photon annihilation and the energy of incident electrons is established. The obtained cross sections for positron interactions with bound electrons of the diffuse component of the non-central, peripheral AGN regions allowed us to obtain new spectroscopic characteristics of the atoms involved in single-photon annihilation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.271-281
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• 2004

Adenoid cystic carcinoma is malignant tumor in salivary gland, and its behavior is very invasive. Of all malignant tumor adenoid cystic carcinoma is occured in frequency of 4.4% in major salivary gland, and 1.29% in minor salivary gland. Histopathologically, adenoid cystic carcinoma is characterized by a cribriform appearance, and tubular form and solid nest type tumor can be seen. The tumor cell structure composed of modified myoepithelial cell, and basaloid cell. Extracellular matrix of this tumor cell contains variable ground substance with basement membrane component. Basement membrane matrix composed of collagen fibers, glycoproteins, proteoglycans, and its function is well known that it participate in differentiation, proliferation, and growth of tumor cell. Basement membrane molecule is essential for invasion of peripheral nerve, blood vessel, skeletal muscle in tumor cell of adenoid cystic carcinoma. In many studies, the tumor cell of adenoid cystic carcinoma containing modified myoepithelial cell participate in synthesis of proteoglycan. In this study, tissue sample of adenoid cystic carcinoma of human salivary gland were obtained from 15 surgical specimen, and all specimen were routinely fixed in 10% formalin and embedded. Serial $4-{\mu}m$ thick sections were cut from paraffin blocks. the histopathologic evaluation was done with light microscopy. And, the immunohistochemical staining, characteristics of glycosaminoglycan were observed. For biochemical analysis of glycosaminoglycan, isolation of crude glycosaminoglycan from tumor tissue and Western bolt analysis were carried out. With transmission electomicroscopy, tumor cell were observed. Biologic behavior of adenoid cystic carcinoma was observed with distribution and expression of basement membrane of glycosaminoglycan in tumor cells, The results obtained were as follows: 1. In immunohistochemical study, chondroitin sulfate is postively stained in tumor cell and interstitial space, dermatan sulfate is weakly stained in ductal cell. But keratan sulfate is negatively stained. 2. In immunohistochemical study, heparan sulfate is strong positive stained in tumor cell and basement membrane, especially in invasion area to peripheral nerve tissue. 3. In transmission electromicroscpic view, the tumor cells are composed modifed myoepithelial cells, and contains many microvilli and rough endoplasmic reticulum. 4. In Western blot analysis, the expression of glycosaminoglycan is expressed mostly in heparan sulfate. From the results obtained in this study, tumor cell of adenoid cystic carcinoma is composed modified myoepithelial cell, and glycosaminoglycan of basement membrane molecule of heparan sulfate and chondroitin sulfate mostly participate in the development and invasiveness of adenoid cystic carcinoma by immunohistochemical study and western blot analysis.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.89-99
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• 2008

Imaging assessment of prostate cancer is one of the most difficult sections of oncology imaging. Detecting, localizing and staging of the primary prostate cancer by preoperative imaging are still challenging for the radiologist. Magnetic resonance (MR) imaging provides excellent soft tissue contrast and is widely used for solid organ imaging, but results of preoperative imaging of the prostate gland with conventional MR imaging is unsatisfactory. Positron emission tomography and computed tomography (PET/CT) is the cornerstone in oncology imaging, but some limitations prohibit the assessment of primary prostate cancer with PET or PET/CT. Recent studies to overcome these insufficient accuracies of imaging evaluation of primary prostate cancers with advanced MR techniques and PET and PET/CT are reported. In this article, we review the imaging findings of prostate cancer on variable modalities, focused on MR imaging and PET/CT.

• Economic and Environmental Geology
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• v.25 no.4
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• pp.447-461
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• 1992

The Jurassic granitoids in the study area are divided into the "Gneissose granodiorite" and the "Daebo granodiorite" (1 : 250,000 Jeonju Geological map, 1973). The term of Geochang granodiorite was used in this study instead of "Daebo granodiorite". These granitoids were studied in terms of microscopic observation, petrochemistry, and zircon morphology. The granitoids are mostly granodiorite. Two kinds of progressive variation can also be recognized in the modal quartz~alkali feldspar~plagioclase triangular diagram; the Gneissose granodiorite is in accordance with the trondhjemitic (low k) trend, and the Geochang granodiorite with the granodioritic trend (medium k). The granitoids belong to the calc-alkaline series, and are classified into the I-type (magnetite series). Plagioclase ($An_{25.1}{\sim}An_{30.9}$) in the granitoids shows generally an oligoclase composition. Biotite has a wider range in (Si, Al) solution than in (Fe, Mg) solid solution. Hornblende occurs in a few thin sections of the Geochang granodiorite, and is plotted in the tschermakite field. The zircon prism shows a long variation between the {110} dominant type and the {100} dominant type in the Geochang granodiorite, but only the {110}={100} type in the Gneissose granodiorite. However, zircon crystals in the granitoids are mostly crystallized in a low-to-medium temperature magma. In the PPEF (Prism- Pyramid-Elongation-Flatness) diagram, the Gneissose granodiorite shows a closed scissors type, the Geochang granodiorite, a opened scissors type. It indicates that the Geochang granodiorite might originate from the mixed magma with crustal materials or pre-existed residual magma which had formed the Gneissose granodiorite.

• Education of Primary School Mathematics
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• v.16 no.1
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• pp.1-20
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• 2013

The aim of this study was to develop a gifted educational program in math-gifted class in elementary school using recently developed 4D-frame. This study identified how this program impacted on spatial sense and mathematical creativity for mathematically gifted students. The investigation attempted to contribute to the developments for the gifted educational program. To achieve the aim, the study analysed the 5 and 6th graders' figure learning contents from a revised version of the 2007 national curriculum. According to this analysis, twelve learning sections were developed on the basis of 4D-frame in the math-gifted educational program. The results of the study is as follows. First, a learning program using 4D-frame for spatial sense from mathematically gifted elementary school students was statistically significant. A sub-factor of spatial visualization called mental rotation and sub-factors of spatial orientations such as sense of distance and sense of spatial perception were statistically significant. Second, the learning program that uses 4D-frame for mathematical creativity was statistically significant. The sub-factors of mathematical creativity such as fluency, flexibility and originality were all statistically significant. Third, the manipulation properties of 4D-frame helped to understand the characteristics of various solid figures. Through the math discussions in the class, participants' error correction was promoted. The advantage of 4D-frame including easier manipulation helped participants' originality for their own sculpture. In summary, this found that the learning program using 4D-frame attributed to improve the spatial sense and mathematical creativity for mathematically gifted students in elementary school. These results indicated that the writers' learning program will help to develop the programs for the gifted education program in the future.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.241-248
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• 2001

The main factors of breakthrough are known to sampling time, flow rate, concentration of the sample, temperature, humidity, and the physical characteristics of the solid sorbent tube. However, no study has been reported the effect of temperature and sampling volume on the breakthrough of acharcoal tube during vinyl chloride monomer (VCM) sampling. The objective of this study is to suggest the optimal sampling condition during VCM sampling based on National Institute for Occupational Safety and Health (NIOSH) method. To evaluate adequate sampling volume for VCM without breakthrough, volume of 1, 2, 3, 4, and 5 L each from VCM of 1, 5, 10, 15, and 20ppm at flow rate of 0.05 L/min were sampled in $22^{\circ}C$ and $40^{\circ}C$. At $22^{\circ}C$, in the case of 1, 5, 10, and 15ppm, VCM was adsorbed completely in first section of charcoal tube regardless of sampling volume. But in 20ppm, detection rates are 99.56% in first section and 0.44% in second section. At $40^{\circ}C$ of 1ppm, VCM was adsorbed completely in first section. In 10, 15, and 20ppm, detection rates of second, third, and forth sections were decreased significantly by reduction of sampling volume. In determination of breakthrough based on NIOSH method, no breakthrough was occurred in 20ppm at $22^{\circ}C$. At $40^{\circ}C$, breakthrough was occurred in 10, 15, and 20ppm when sampling volume was 5L. Although no breakthrough was occurred when sampling volume was 3L. Finally, in environment of temperature around $22^{\circ}C$, breakthrough may not occurred up to 20ppm during sampling for VCM. During sampling for VCM in environment of temperature around $40^{\circ}C$, no breakthrough occurred in 1-5ppm and 10-20ppm when sampling volume is 5L and 3L respectively. This result suggests that the sampling volume should be considered when VCM sampling under hot conditions (> $22^{\circ}C$) by the NIOSH method No. 1007.

• Journal of Hospice and Palliative Care
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• v.14 no.4
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• pp.204-211
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• 2011

Purpose: This study used a nonequivalent control group pre-post test design to analyze how a death preparation education program helps middle-aged adults deal with life and death anxiety. Methods: We studied 83 adults at the age of 40 to 65 years. An experimental group of 38 people participated in the death preparation education, and a control group of 45 people did not. The death preparation program comprising four sections was given for four hours per week, and the program ran for 11 weeks. Data were analyzed by descriptive statistics, t-test, ${\chi}^2$ test, Fisher's exact test, and ANCOVA using SPSS version 17.0. Results: The death anxiety score of the experimental group was significantly lower than that of the control group (P<0.000). The quality of life did not show significant difference between the experimental and control groups (P=0.188). Conclusion: It was confirmed that the death preparation education program is effective in alleviating death anxiety. Although the program was confirmed as a necessity for the middle-aged adults, repeated observations with a wider range of experimental group is needed to collect objective and solid data. Death preparation education for middle-aged adults is expected to be more widely provided, starting from local health facilities.

• Journal of Service Research and Studies
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• v.11 no.3
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• pp.1-16
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• 2021

Recently, crowdfunding has been receiving increased attention due to the variety of novel ways it provides for connecting funders and fundraisers. Concurrently, however, it has been criticized on the grounds of information asymmetry. We are interested in whether information collected from an asymmetric information source significantly influences crowdfunding success. Through this study, we would like to establish a social field of convergence pursued by Serve Science and to conduct practical research and practice together. First, we investigated the importance of interaction between funders and fundraisers within the crowdfunding platform. In the "comments" section, communication between funders and fundraisers reduces the degree of asymmetric information. In the aspect of presumable funders, they should make the best of the "comments" section to collect more solid information without losing return on their investment. Second, we analyze sentiment-based optimistic and pessimistic information from the "story" (asymmetric source) and "comments" sections. In conclusion, it shows that the optimistic and pessimistic information of the "comments" section has a great impact on crowdfunding success and that the influence of the "story" section is limited to pessimistic information under certain conditions. The crowdfunding platform is an innovative and productive way for startups and entrepreneurs to start a business, and since information an important role in the success of crowdfunding, It can be seen that it is essential to focus on establishing the best communication methods.

• Journal of dental hygiene science
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• v.17 no.4
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• pp.283-289
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• 2017

The water discharged from dental unit waterlines (DUWLs) is heavily contaminated with bacteria. The development of efficient disinfectants is required to maintain good quality DUWL water. The purpose of this study was to establish a DUWL biofilm model using well-plates to confirm the effectiveness of disinfectants in the laboratory. Bacteria were obtained from the water discharged from DUWLs and incubated in R2A liquid medium for 10 days. The bacterial solution cultured for 10 days was made into stock and these stocks were incubated in R2A broth and batch mode for 5 days. Batch-cultured bacterial culture solution and polyurethane tubing sections were incubated in 12-well plates for 4 days. Biofilm accumulation was confirmed through plating on R2A solid medium. In addition, the thickness of the biofilm and the shape and distribution of the constituent bacteria were confirmed using confocal laser microscopy and scanning electron microscopy. The average accumulation of the cultured biofilm over 4 days amounted to $1.15{\times}10^7CFU/cm^2$. The biofilm was widely distributed on the inner surface of the polyurethane tubing and consisted of cocci, short-length rods and medium-length rods. The biofilm thickness ranged from $2{\mu}m$ to $7{\mu}m$. The DUWL biofilm model produced in this study can be used to develop disinfectants and study DUWL biofilm-forming bacteria.

• Journal of Life Science
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• v.18 no.1
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• pp.16-22
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• 2008

In this study to evaluate the involvement of EGFR, HER-2/neu and ALCAM (CD166) oncogene products in canine mammary neoplastic lesions, sections of archived paraffin-embedded samples of 49 mammary tumors were analyzed immunohistochemically using antibodies against human EGFR and HER-2/neu and ALCAM. These 49 tumors were divided into 2 groups: 22 benign (19 adenoma, 3 benign mixed tumors) and 27 malignant tumors (2 simple adenocarcinomas, 5 complex adenocarcinomas, 3 solid carcinoma, 5 sclerosing carcinoma, 8 malignant mixed tumors and 4 malignant myoepithelioma). As a result of immunostaining, 31.8% (7/22) of the benign tumors and 29.6% (8/27) of the malignant tumors expressed the HER-2/neu oncogene product, EGFR expression was detected in 27.3% (6/22) of benign tumors and in 22.2% (6/27) of the malignant tumors. ALCAM expression was detected in 40.9% (9/22) of benign tumors and in 7.4% (2/27) of the malignant tumors. These results suggest that some of the biological and morphological characteristics of the tumor are associated with canine mammary gland tumors, as also reported for human breast cancer, the possibility of using anti-HER-2/neu antibodies in the treatment of canine mammary tumors.