• Restorative Dentistry and Endodontics
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• v.14 no.1
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• pp.85-96
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• 1989

In the Infected root canals, the majority of the isolated bacteria are either strict anaerobes or microaerophilic organisms. Among thease, Black-pigmented Bacteroides species are the most important and have relation with clinical symptoms. The purpose of this study were to investigate on the 7 different types of bacteria which include Black-pigmented Bacteroides - Black--pigmented Bacteroides, Actinobacillus actinomycetemcomitans, Streptococcus, Capnocytophaga, Eiknella corrodens, Fusobacterium, Actinomyces - and the interrelationship between these 7 bacterical species, and to compare Black-pigmented Bacteroides with the clinical symptoms in infected root canals. The canal contents of 15 necrotized teeth with 8 clinical symptoms were sampled and cultured aerobically and anaerobically for growth in 7 selective agar plates for 7 bacterial species. Black-pigmented Bacteroides and Streptococcus subspecies were identified by biochemical tests. The results were as follows; 1. 70.51% of the bacteria isolated were anaerobes and 29.49% were aerobes. 2. B. loescheii, B. intermedius, B. denticola were isolated in 8 cases, Streptococcus was isolated in 8 cases, Fusobacterium was isolated in 6 cases, Actinomyces was isolated in 5 cases and Eiknella corrodens, Actinobacillus actinomycetemcomitans, Capnocytophaga were not isolated. 3. There were mutual inhibition of growth between Black-pigmented Bacteroides and Streptococcus. (P<0.01) But Actinomyces and Fusobacterium showed mutual aids for growth. (P<0.05) 4. Black-Pigmented Bacteroides was found to be related both to sinus tract formation and to apical sensitivity to palpation.(P < 0.05).

• Journal of the Korean Society for Heat Treatment
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• v.16 no.3
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• pp.134-140
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• 2003

Effects of cryogenic treatment and tempering temperature on the amount of retained austenite, hardness and wear properties has been investigated using alloy tool steel, STD 11. Cryogenic treatments were performed at the temperatures of $-100^{\circ}C$, $-150^{\circ}C$ and $-196^{\circ}C$, and tempering were performed at $200^{\circ}C$ and $530^{\circ}C$. It was shown that lower hardness value was obtained on high temperature ($530^{\circ}C$) tempering even after cryogenic treatment. And retained austenite was not entirely transformed to martensite after cryogenic treatment even at $-196^{\circ}C$, which was not consistent with the belief that $-80^{\circ}C$ was sufficient to entirely transform any austenite retained in the quenched microstructure. Austenite retained in cryogenic treated condition was completely transformed to martensite only after tempering at $530^{\circ}C$. As far as wear test conditions in this investigation, it was found that cryogenic treatments improved the sliding wear resistance, but improvement of wear resistance was not directly related with retained austenite contents. And it was found that predominent wear mechanisms of STD 11 steel were oxidation wear and adhesive wear In sliding wear conditions.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.241-243
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• 1998

The chemical composition of rice germ, a by product of rice milling, was analyzed and its oil stability was evaluated by acid value and Rancimat method during storage. The predominent components of the germ were carbohydrate (36.5%). crude lipid (21.6%) and crude protein (18.7%). The time taken to double the acid value was 2 days for common rice germ, while it took 31 days to increase 1.15 times for rice germ dried at $80^{\circ}C$ for 6 hours. Induction periods of the lipid oxidation from common or dry germ stored at different temperature were not significantly different.

• Journal of Korean Academy of Nursing
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• v.23 no.3
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• pp.453-466
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• 1993

Quantitative methodology has been the predominent methodology utilized in research in nursing. However since the 1970s qualitative methodology has also emerged as a useful methodology and has been utilized by many researchers. But in the use of this methodology, the philosophical, epistemelogical, and theoretical backgrounds have been neglected by many researchers. This paper reports a review of the literature on methodologies, quanitative and qualitative, used in nursing, and makes suggestions for future research directions. It explains why qualitative methodology has emerged as as effective methodology in nursing and discusses how the qualitative methodology differs from the quanitative one. A comparison of the two is made based on perspectives of humane being and human behavior as well as the development of nursing science. This paper also presents several views on change in nursing science, since viewpoint not only influences the determination of the current stage of nursing science but also the shaping of the future directions of nursing science and research. Scientific revolution by Kuhn, the evolutionary perspective by Toulmin, the transition of research tradition by Laudan. and convolutionary processes are presented. However, this paper indicates that it is too early to adopt these points of view, because the history of nursing science is too short. It suggests that nursing needs pluralism in philosophy, paradigms and theory, as well as in methodology. Although we experience paradoxes in adopting different perspectives in nursing, it is wise for us to continue to include a variety of viewpoints including those to which we are not accustomed, such as qualitative methodology, since we are not yet able to decide what is best for the development of nursing science.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.15 no.1
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• pp.67-74
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• 1985

The incidence and associated dental abnormalities of taurodontism were studied radiographically (panoramic view) in 1895 patients of deciduous dentition and 2167 patients of permanent dentition who had visited to the Department of Oral Radiology, Kyung Hee University in Korea. The obtained results were as follows: 1. The prevalence of taurodontism was 3.59% in the deciduous dentition group, and 1.8% in the permanent dentition group. 2. There was no definite sex difference in the deciduous dentition, and the permanent dentition group. The type of mesotaurodontism was predominent in the deciduous dentition group, and hypotaurodontism in the permanent dentition group. 4. The vast majority of this abnormalities had occurred in the mandibular 1st deciduous molar in the deciduous dentition group, and mandibular 2nd permanent molar in the permanent dentition group. 5. Of the cases with taurodontism, the deciduous dentition group revealed 95.6% bilaterally, and 82% bilaterally in the permanent dentition group. 6. Multiple teeth occurance, not single tooth only, were involved in 98.5% of the cases in the deciduous dentition group, and 82% in the permanent dentition group.

• Journal of the Korean Ceramic Society
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• v.30 no.11
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• pp.881-890
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• 1993

MAS system has narrow sintering temp. range due to the liquid phae sintering and thereby densify rapidly. And especially, its poor mechanical properties limitedthe industrial application. In this study, the improvement of mechanical properties and densification is suggested by the consideration of the toughening mechanisms and isolated pore generation mechanism which is derived by the liquid phase sintering theory in 3Y-TZP added composites. After Pressureless sintering up to 140$0^{\circ}C$ for 5hr, the dihedral angle and contact angle are analyzed by the observation of microstructure. As a result of microstructure analysis, the sintering stage of the specimen sintered for 5hr is analyzed as solid-skeleton stage. And the isolated pore generation mechanisms are considered as (1) The swelling of the liquid phase is predominent due to the facts that dihedral angle is larger than 60$^{\circ}$, contact angle is large and that liquid volume fraction is smaller than 10%. (2) The porous characteristics of the MAS system is also suggested as: the SiO2-rich liquid film is firstly formed at the srface and therefore this reduces the contiguity of the pore, which induces the isolated pore. The strength and fracture toughness increased with the addition of 3Y-TZP and the main fracture toughness improvement mechanisms are analyzed as the crack deflection.

• The Journal of Pediatrics of Korean Medicine
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• v.18 no.1
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• pp.179-191
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• 2004

Objective: The aim of this study was to investigate enuretic children attending oriental hospital and classify subtypes and evaluate possible factors that enhance or hamper of continence. Methods: Children attending kyeongju dongguk oriental hospital pediatrics between January 2000 and December 2003 with chief complaint of nocturnal enuresis were enrolled. The data of present symptoms and improvement progress was collected via telephone interviews with their parents. Results: The total number of children was 61. 32 of them were male and 29 female. Sex ratio was 1.1:1. Patient under 6 years of age was 68.8%. Using acupuncture, acupressure or chimsband with herb medicine, treatment frequency was increased. Patients with nocturnal enuresis(NE) was 48, and primary nocturnal enuresis(PNE) 39, secondary (SNE) 9. 13 was impossible to diagnose. The ratio of male to female was 1:1.09. PNE was 4 times as many as SNE. Male was predominent in PNE, and female in SNE. In the progress of PNE, male and female were similiar. but SNE, male was all cured, female remained 50%. And elapsed time of male to improve was longer than that of female. In the progress of improvement, many parents mentioned that their child was improved spontaneously regardless of subtype. Conclusion: We consider age, sex distinction, subtype, bladder symptoms, frequency, time of progress as influencing factor of prognosis, but failed to verify significance. To develop guideline of NE and find influencing factor of prognosis, more prospective study through taking history carefully and using questionnaire is needed.

• The Korean Journal of Cytopathology
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• v.8 no.2
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• pp.135-142
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• 1997

Mucoepidermoid carcinoma is the most common malignant neoplasm of the salivary gland, compring between 30 and 40%. Fine needle apsiration cytology was performed in five patients with mucoepidermoid carcinoma. The patients consisted of three males aged of 42, 48, and 60 years, and two females aged 36, and 56 years. The primary tumor sites were the parotid gland in four patients and the submandibular gland in the rest one. The histologic grades were low in one patient, intermediate in two patients and high in other two. In our experience, the common cytologic findings of low grade subtype were predominent mucous cells with some intermediate cells in an abundant mucinous background. The cytologic findings of intermediate grade subtype were predominant clusters of intermediate cells with or without mucous cells in an abundant mucinous background. And the cytologic findings of high grade subtype were predominant clusters of epidermoid cells with intermediate cells in a bloody background. Cytologic pleomorphism and atypia were more severe in high grade than low and intermediate grade, and nucleoli were more frequently noted in epidermoid cells. In low grade, it is very difficult to decide the benignancy or malignancy of the tumor. In fact, the presence of mucous cells in a mucinous background should rule out any other type of well differentiated carcinoma.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.261-270
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• 2004

The purpose of this experiment was to examine the histological changes and the pattern of expression of type I, II collagen in the elongated area by distraction osteogenesis in the rabbit mandible. Sixteen rabbits weighing 2.5kg-3kg were used for this experiment. Experimental group was distracted at the rate of 0.7mm, twice/day for 7days, and control group was only osteotomized. After 5 days latency, osteotomic site is distracted for 7days. Consolidation period is 28days. The animal was sacrificed at the 3rd, 7th, 14th, 28th day after the operation. The distracted bone was examined by histological analysis and RT-PCR analysis. The results were summarized as follows: 1. Experimental group was observed that the gaps between the distracted bone edges were occupied by new bone. 2. Expression of Type I collagen were detected throughout the experiment in both groups and Expression of Type I collagen were markedly increased during distraction and consolidation period in experimental group than control group. 3. Expression of Type II collagen were detected throughout the experiment in both groups and expression of Type II collagen were maintained at high level during distraction and consolidation period in experimental group than control group. From these results, in contrast to type II collagen, type I collagen seemed to be more expressed by mechanical stimuli during distraction and consolidation period. The predominent mechanism of new bone formation in the distraction gap was intramembranous bone formation, but some of the regenerated bone was formed by endochondral ossification.

• Journal of the Korean Geographical Society
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• v.28 no.3
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• pp.193-199
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• 1993

The interannual fluctuation, trends and perio-dicties in summer rainfall of South Korea were analyzed primarily by using Mann-Kendall rank method and Power Spectrum analysis for the period from 1920 to 1985. Their relations to Indian summer monsoon rainfall have also been examined. Increasing or decreasing rainfall tendencies are not found in South Korea. In Power Spectrum alalysis, 2.5 years periods are predominent at the 95 per cent confidence level in south Korea as a whole and Pusan. Also the period of 11.0 years is found in Seou. There are another prominent spectral peaks at 2.4, 3.1, 6.2 and 7.3 years period, which are significant at 90 per cent confidence level.