• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.122-132
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• 2023

The external morphological characters of six taxa of the genus Melampyrum in Korea (M. roseum, M. roseum var. japonicum, M. roseum var. ovalifolium, M. setaceum, M. setaceum var. nakaianum, and M. koreanum) were observed to identify the taxonomic entity. The taxonomically useful characters, confirmed in this study, were as follows; the shape of leaf and bract, the number and location of the setose teeth at bract margin, the shape of cross-section and distribution of hair on the stem, the shape of bract base, the shape and protuberance type of calyx lobes, the color and length of the corolla, and the shape of the capsule. Based on these results, a key to the Korean Melampyrum taxa is provided.

• Journal of Korean society of Dental Hygiene
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• v.22 no.6
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• pp.467-475
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• 2022

Objectives: This study aimed to understand the definitions, types, and principles of computer-aided design/computer-aided manufacturing (CAD/CAM) and scanners due to the introduction of digital workflows. Methods: This study was based on information from the government's law and articles published in academic journals. Results: CAD/CAM is a technology that measures the shape three-dimensionally, saves it as data, designs it into the desired shape, and processes the product. Scanners, which are classified as intraoral and extraoral scanners, measure teeth and the intraoral environment three-dimensionally and convert them into three-dimensional (3D). A 3D printer is a machine that creates a 3D object by layering materials based on a 3D drawing. It can be classified into four types according to the method: extrusion, powder bonding, lamination, and photopolymerization methods. The most used 3D printer methods in dentistry are stereolithograhpy and digital light processing, and they are widely used in prosthetic, surgical, and orthodontic fields. Conclusions: As the dental system is digitized, it is expected that the government will classify the dental hygienist scope of work and the universities will reflect the curriculum; it is necessary to develop excellent dental hygienists, diversify the educational pathways, and establish policies to meet the needs of the increasing number of patients.

• Tribology and Lubricants
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• v.34 no.1
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• pp.23-32
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• 2018

Coupling is a mechanical component that transmits rotational force by connecting two shafts. Curvic coupling is widely used in high-performance systems because of its excellent power transmission efficiency and easy machining. However, coupling applications change dynamic behavior by reducing the stiffness of an entire system. Contact surface stiffness is an important parameter that determines the dynamic behavior of a system. In addition, the roughness profile of a contact surface is the most important parameter for obtaining contact stiffness. In this study, we theoretically establish the process of contact and bending stiffness analysis by considering the rough surface contact at Curvic coupling. Surface roughness parameters are obtained from Nayak's random process, and the normal contact stiffness of a contact surface is calculated using the Greenwood and Williamson model in the elastic region and the Jackson and Green model in the elastic-plastic region. The shape of the Curvic coupling contact surface is obtained by modeling a machined shape through an actual machining tool. Based on this modeling, we find the maximum number of gear teeth that can be machined according to the contact angle. Curvic coupling stiffness is calculated by considering the contact angle, and the calculation process is divided into stick and slip conditions. Based on this process, we investigate the stiffness characteristics according to the contact angle.

• Korean Journal of Veterinary Research
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• v.49 no.1
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• pp.67-71
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• 2009

A 10-year old female Yorkshire terrier with nasal discharge and swelling was referred to the local animal hospital. Abnormal mass of right nasal cavity was detected in physical examination and radiography. According to the radiographs of the head, there was an evidence of bony destruction in right nose. Oronasal fistula was detected in right maxillary canine teeth. After surgical excision, the sample of nasal mass was refereed to Pathology Department of Veterinary Medicine in Jeju National University. Grossly, the enlarged mass was soft and 3 ${\times}$ 3 cm in size. Histopathologically, the neoplastic mass was composed of tubular to tubulopapillary structures which were lined by single to 6~7 layers of cuboidal to ciliated columnar cells. These neoplastic cells showed invasive tendency to adjacent normal parenchyma. They had uniform, round to oval nuclei, cytoplasm with small vacuoles and indistinct cellular margin. The number of mitotic figures was varied in different areas, ranged from 0 to 4 per high power field. Necrotic foci and infiltration of inflammatory cells including neutrophils, lymphocytes, and plasma cells also presented in the mass. Immunohistochemically, the neoplastic cells demonstrated strong positive reaction for cytokeratin (CK) 18 but were negative for CK 7 and 8. Based on the gross, histopathology and immunohistochemistry, this mass was diagnosed as nasal adenocarcinoma originated from respiratory epithelium.

• Journal of Periodontal and Implant Science
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• v.40 no.6
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• pp.257-264
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• 2010

Purpose: Connective tissue reattachment to periodontally damaged root surfaces is one of the most important goals of periodontal therapy. The aim of this study was to develop a root conditioning agent that can demineralize and detoxify the infected root surface. Methods: Dentin slices obtained from human teeth were treated with a novel root planing agent for 2 minutes and then washed with phosphate-buffered saline. Smear layer removal and type I collagen exposure were observed by scanning electron microscopy (SEM) and type I collagen immunostaining, respectively. Cell attachment and lipopolysaccharides (LPS) removal demonstrated the efficiency of the root conditioning agent. Results: SEM revealed that the smear layer was entirely removed and the dentinal tubules were opened by the experimental gel. Type I collagen was exposed on the surfaces of the dentin slices treated by the experimental gel, which were compared with dentin treated with other root planing agents. Dentin slices treated with the experimental gel showed the highest number of attached fibroblasts and flattened cell morphology. The agar diffusion assay demonstrated that the experimental gel also has effective antimicrobial activity. Escherichia coli LPS were effectively removed from well plates by the experimental gel. Conclusions: These results demonstrated that this experimental gel is a useful tool for root conditioning of infected root surfaces and can also be applied for detoxification of ailing implant surface threads.

• Journal of Korean society of Dental Hygiene
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• v.14 no.2
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• pp.231-240
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• 2014

Objectives : The purpose of this study was to examine the oral health programs for children of the low income classes in order to prevent oral health problems and to provide the effective oral health programs in community children's centers. Methods : The subjects were 464 teachers in community children's centers in Seoul, Incheon, Gyeonggi-do, Chungcheongbuk-do, and Jeollabuk-do. Results : There were differences between the regions(p<0.05) in oral health guidance among teachers in municipal and provincial community children's centers. The oral health education was considered as the most important thing in those who had more than 6 years career(71.8%), and followed by those having less than five years career(61.3%) and those having two years career(53.8%)(p<0.05). Although many children registered the program and newsletter was sent to the children's homes, but 70% of the children did not brush their teeth regularly(p<0.05). Regardless of region, gender, teaching career, and number of enrolled children, 90 percent or more people found that it necessary for community children's centers to collaborate with dental clinics. There were gender differences between the male and female(p<0.05). Male accounted for 42.4% response rate and female accounted for 36.4%. Approximately About 48.5% of male and 61.6% of female thought that the oral health program is the most important thing(p<0.05). Conclusions : The development of the customized oral health program is the most critical factor to the oral health behavior change in the children in the community children's centers and public dental clinics.

• Research in Community and Public Health Nursing
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• v.12 no.1
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• pp.168-174
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• 2001

This study was conducted to investigate the disease preventive behavior and health promoting behavior of a community residents. The subjects were selected by convenient sampling and the total number was 300(Female, 170, Male, 130). The data were collected by face to face interviews during the period of Sep. 15-30, 1999. The measurement tool for this study was the rating score for disease preventive behavior and health promoting behavior. The instrument was developed by the researcher based on the tool of Korea Institute for Health and Social Affairs. The data were analyzed by percentage, mean, t-test, ANOVA. $x^2-test$ by Windows SPSS/PC program(v7.5). The results were as follows: 1. In the comparison of disease preventive behavior rates between male and female, there was a statistically significant difference in physical examination, measuring the blood pressure and vaccination for B type hepatitis. In the comparison of disease preventive behavior rates among the age, there was a statistically significant difference in physical examination, measuring the blood pressure. 2. The rating score for the health promoting behavior of the men subjects was lower than that of the women subjects. In the comparison of health promoting behavior scores between male and female, there was a statistically significant difference in smoking, drinking, regular exercise, breakfast eating, vegetable consumption and teeth brushing. In the comparison of promoting Behavior scores among the age, there were significant difference, there was a statistically significant difference in smoking, sleeping, seat belt use, breakfast eating and salty eating.

• Journal of Korean society of Dental Hygiene
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• v.22 no.5
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• pp.333-340
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• 2022

Objectives: This study aimed to confirm the association between cognitive function and oral health status in the elderly. Methods: In this study, 5,794 respondents, aged 55 or older, who had participated in the 7th aging research panel survey were used. Statistical analyses were performed using a complex samples cross-tabulation analysis, complex samples general linear model, and a complex sample multinomial logistic regression analysis. Results: After analyzing the cognitive function of the elderly according to their oral health conditions, it was found that suspicions of dementia (19.6%) and cognitive function decline (25.9%) were more common for those who wore dentures than for those who did not wear dentures (p<0.001). Compared to those who did not wear dentures, those who wore dentures were linked to a 1.665 times higher suspicion of dementia (p<0.001). In comparison, cognitive decline was 0.964 times lower when the number of natural teeth increased by 1, and it was 0.941 times lower when the oral health evaluation index for the elderly increased by 1 point (p<0.001). Conclusions: As a result of this study, it was confirmed that cognitive function and oral health status are related in the elderly. Therefore, systematic measures for oral health management and oral health promotion should be prepared in tandem with awareness of possible cognitive decline in the elderly.

• Journal of the Korean Society of Safety
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• v.23 no.4
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• pp.13-18
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• 2008

This study deals with finish roll forming by forced displacement can be conceived as a method of eliminating errors in conventional form rolling under constant loads. This method produces a high-precision tooth profile by low-speed form rolling when a high rigid screw or cam is used at the pressurized section. Tooth profile is decided in the beginning of roll forming and ${\delta}_{max}$ mainly increases if the number of roll forming process is increased. Gear class is improved by one or two class after roll forming if the gear has convex type error and pressure angle error in KS 4 class. If the gear have concave type error and pressure angle error and pressure angle error, gear class is not improved in theory, but improved a little in practice. In the finishing roll forming, it inevitably yields both the concaving of tooth profile and plastic deflection of addendum of teeth. Experiments show that the concaving and the plastic deflection are successfully reduced, the accuracy of tooth profile reaches to KS 0 class.

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.111-121
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• 2005

Coronary heart disease is the leading cause of mortality in adult population. Whereas the association between periodontal disease and coronary heart disease (CHD) are controversial, recent studies reported the association between periodontal disease and acute myocardial infarction or prognosis of CHD. This study was aimed to investigate the relationship between periodontal disease and angiographically defined CHD, and acute myocardial infarction, and the prognosis of treated CHD. Patients under the age of 60 who had undergone the diagnostic coronary angiography were enrolled in this study, Subjects were classified as positive CHD (+CHD, n=37) with coronary artery stenosis more than 50% in at least one of major epicardial arteries, and negative CHD (-CHD, n=20) without stenosis. After recording the number of missing teeth, periodontal disease status was measured by means of plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL), Positive CHD subjects were classified into acute myocardial infarction group (AMI), and non-AMI with angina pectoris and old myocardial infarction. Six months postoperatively, positive CHD subjects were followed and had undergone the coronary angiography again. Even though there was no significant difference in the periodontal parameters and status between positive CHD and negative CHD, some periodontal parameters, such as mean probing depth and proportion of sites with probing depth greater than 4mm or 6mm were significantly different between AMI and Non-AMI(p<0.05). There was no significant difference in the periodontal parameters according to in angiographically follow-up status. These results indicate that periodontal disease may be associated with the occurrence of acute myocardial infarction.