• Journal of radiological science and technology
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• v.32 no.1
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• pp.101-106
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• 2009

Purpose of this study is to compare the signal intensity (SI) and CNR with T1 weighted image using FLASH at 3T abdominal MRI by varying flip angle (FA). Totally 20 patients (male : 12, female : 8, Age : $28{\sim}63$ years with mean : 51) were examined by 3 Tesla MR scanner (Magnetom Tim Trio, SIEMENS, Germany) with 8 channel body array coil between september and October 2008. Imaging parameters were as follows : FLASH sequence, TR : 120 ms, TE : minimum, FOV (field of view) : $360{\times}300\;mm$, Matrix : $256{\times}224$, slice : 6 mm, scan time : 15 sec and Breath-hold technique. Abdominal image, with a 50 ml syringe filled with water placed in the FOV measuring the water signal, were acquired with varying FA through $10^{\circ}$ to $90^{\circ}$ with $10^{\circ}$ interval. SI's were measured three times at liver parenchyme, water, spleen and background and averaged. The CNR's were measured between the ROIs (region of interest). Statistic analysis was performed with ANOVA test using SPSS software (version 17.0). Less than FA $30^{\circ}$, abdominal images were severely inhomogeneity. Especially, T1 effect of water signal was weak. As the flip angle increased, the signal intensity decreased at all the regions. Especially, flip angle of the highest signal intensity was observed with $40^{\circ}$ at the liver parenchyme, $20^{\circ}$ at water, $30^{\circ}$ at the spleen, respectively. The CNR between liver and water was -60.92 at FA $10^{\circ}$ and 15.16 at FA $80^{\circ}$. The CNR between liver and spleen was -3.18 at FA $10^{\circ}$ and 9.65 at $80^{\circ}$. In conclusion, FA $80^{\circ}$ is optimal for T1 weighted effect using FLASH pulse sequence at 3.0 T abdominal MRI.

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.195-207
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• 2002

Numerous studies have revealed the similarities and discrepancies in two divisions of class II malocclusion, since these malocclusion groups have been postulated to be disparate criterion, much as classified under one diagnostic umbrella. This study was undertaken to describe the craniofacial configurations of class II division 1 and 2, and consequently to discriminate the morphologic differences between the two malocclusion groups in Korean sample. Lateral headfilms of 34 class H division 1 and 29 division 2 were employed, while those of 142 adults of normal occlusion served as a control. The landmarks were digitized and 26 variables were statistically analyzed for one way ANOVA. 1. There manifested no statistically significant difference in maxillary position anteroposteriorly. Normal occlusion group exhibited most anteriorly positioned mandible, whereas class II division 1 showed the most retroposition. Class II division 1 disclosed clockwise rotation tendency of mandible, which resulted in position of the chin Posteriorly. 2. Class II division 1 showed greater in SN to MP, SN to PP significantly than other groups. 3. Class II division 2 showed smaller genial angle and larger mandibular body length than other groups. 4. Class II division 1 revealed greater anterior lower face height than other groups, whereas division 2 dictated significantly greater posterior face height. 5. Class II division 2 expressed the most retroclined lower incisor, while division 1 manifested the most proclination. The largest interincisal angle resided in Class II division 2 group. There were no significant differences in upper molar position anteroposteriorly.

• Journal of dental hygiene science
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• v.6 no.4
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• pp.271-276
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• 2006

This study set out to analyze the relationships between the senior citizens' dental health activities and dental health conditions, to provide basic data to develop a program for their better dental health, and finally to search for the ways to improve their life quality through dental health care. The subjects were 142 senior citizens(58 were male and 84 were female) who were 65 years old or older and visited a dental hospital or clinic in the Seoul metropolitan area from April 17 to April 28, 2006. With the cooperation from the dentists, the investigators examined their dental conditions and conducted one-on-one interviews to collect the information about their demographic characteristics, dental health activities, and subjective dental health conditions. The collected data were analyzed with T-test, ANOVA and Pearson's correlation coefficient using the SPSS WIN 11.5 program. The analysis results were summarized as follows: First, 58 men(40.8%) and 84 women(59.2%) consisted of the subject group, where percentage of the female participants was bigger Those who were aged from 65 to 69 made the biggest age group in the subjects, accounting for 58.5% with 83. Second, those who had three dental caries or less and then didn't treat them or treated them(F) accounted for the biggest percentage with 117(82.4%) and 72(50.7%) respectively. As for the remaining teeth, the biggest number of them(40 subjects, 28.2%) had three or less remaining. Third, it turned out the female subjects had a higher level of dental health activities than their male counterparts(P = 0.00). As for living expenses, those who were paid salary or earned income themselves carried out their dental health activities in a higher level than those who lived on the benefit from the government(p = 0.02). Fourth, the subjects' subjective dental health conditions had negative correlations with their dental caries not treated. And there were positive correlations between their dental caries not treated and dental caries lost and between their dental caries treated and remaining teeth. Fifth, those subjects who earned their living expenses themselves had the most dental caries treated at 5.4(p = 0.02), and there was statistically significant difference with the numbers. Sixth, those subjects who brushed their teeth in their own manner had 11.8 teeth lost(p = 0.05), which was more than the number of those who brushed their teeth in other methods. And there was statistically significant difference among them. The remaining teeth were found most at 17.3(p = 0.00) among those who brushed their upper and lower teeth separately. In addition, those who visited the public health center often had significantly more teeth treated(4.3) than others(p = 0.00).

• Research in Community and Public Health Nursing
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• v.1 no.1
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• pp.465-502
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• 1989

The purpose of this study was to find out the general characteristics of school health teachers, the status of school health resources and the degrees of self-confident performance for the 124 school health teachers in Pusan City. Data was collected by means of questionaires from Aug. 1986 to Mar. 1987. The data were analyzed by use of percentage, mean, standard deviation, t-test, ANOVA and Pearson-correlation coefficient. The results of this study were as follows: 1 . General Characteristics of School Health Teachers (SHT) 1) The average of age of the SHT was 32.8 years old and 39.5% of them were from 30 to 34 years old. 2) The average for school nursing experience of the SHT was 7.9 years and 37.9% of them were from 5 to 9 years. 3) The 45.2% of them have not the clinical experience. 4) The 74.2% of them were graduated from the 3 years college of nursing. 2. Status of school health resources and nursing activities. 1) The average of student number was 2497.3 and class number was 45.2. 2) The average of school health budget was 1039000 won and 27.7% of school health budget expended on examination cost. 3) Only 29.0% of all schools have organization for school health. 4) The 84.7% of all schools have health clinic separately and 69.1% of schools have less than $33m^2$ sized. 5) The average of clinic visitor number was 2111.8 for 1 year. 6) Major problem was on digestive system. And other problems were skin, respiratory, musculo-skeletal system and dental problem. 7) The number of literal message was 14.4 times for 1 year. 3. The degree of the school health teachers' self-confidence. The school health teachers' self-confidence was deviced into 6 and the maximum degree was 4. 1) Program planning & evaluation; 2.8 2) Clinic management; 2.9 3) Health education, 3.0 4) Management of school environment; 2.7 5) Health care services; 2.7 6) Operating of school health organization; 2.4 4. Significances to the degree of self-confidence on school health nursing activities. 1) There was significant difference between clinical management and Religion (t=2.15 p<.05) 2) There was significant difference between Operating of school health organization and level of school (F=3.588 p<.05) 3) Program planning & evaluation: expending time for clinical management (r=-0.184 p<.05) expending time for health care services (r=0.273 p<.01) 4) Clinical management: use of separate health clinic (r=0.151 p<.05) 5) Health education: use of separate health clinic (r=0.170 p<0.5) 6) Health care services: No. of student (r=-0.144 p<0.5) No. of class (r=-0.160 p<.05) 5. The degree of the school health teachers' self-discipline. The school health teachers' self-discipline was devided into 2 and the maximum degree was 2. 1) Program planning & evaluation:1.8 2) Clinic management: 1.9 3) Health education: 1.9 4) Management of school environment: 1.7 5) Health care services: 1.8 6) Operating of school health organization.: 1.3 6. Significances to the degree of self-discipline on school health nursing activities 1) Program planning & evaluation; Level of nursing education (F=4.309 p<.01) 2) Clinical management: Level of nursing education (F=3.587 p<.05) 3) Operating of school health organization: School health organization (t=-2.68 p<.01) 4) Health care services: School health organization (t=2,58 p<.05) 5) School health performance: School health organization (t=2.32 p<.05) 6) Program planning & evaluation: School health experience (r=0.239 p<.01) Expending time for program planning & evaluation (r=-0.172 p<.05) 7) Clinic management: School health experience (r=0.249 p<.01) Expending time for dinic management (r=0.181 p<.05) No. of student (r=-0.158 p<.05) Expending time of program planning & evaluation (r=-0.199 p<0.5) 8) Health education: School health experience (r=0.234 p<0.1) Expending time of program planning & evaluation (r=-0.193 p<.05) 9) Management of school environment: Age of school health teacher (r=0.142 p<.05) School health experience (r=0.255 p<.01) 10) Operating of school health organization: Medicine Purchase (r=-0.163 p<.05) 11) Health care services: School health experience (r=0.148 p<.05) Medicine purchase (r=-0.229 p<.01) 12) Total school health performance: School health experience (r=0.200 p<.05) Medicine purchase(r=-0.168 p<.05) Based on the above results, the suggestions are as follows: 1) As the SHT take charge of the reasonable number of student, the students will have benefit of the good health service in quality. 2) It is recommended to use the health clinic separately and to arrange adequate place for good school health service. 3) It is necessary that the SHT participate budget for school health. 4) It is required to enhance self-confidence on school health nursing activities through continuous educational programs.

• Culinary science and hospitality research
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• v.8 no.1
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• pp.55-69
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• 2002

Sedum Sarmentosum Bunge has been used as medical material and food in Korea. To upgrade it's value as a materials of beverage, I research and analysed nutritive substance and taste. Inorganic components content was included in the order of Ca, mg, P, K, Na, in line, and there were little Fe, Cu, Zn. It appeared much Ascorbic acid contents in May sample for March sample, but it was included less than other Green Vegetables. Chlorophyll contents decreased about 37.8% and 37.6% to the first each contents after seven days resulting measuring May sample and March sample in room temperature. There was much difference in appearance. Sedum Sarmentosum Bunge included a little polyphenol contents. Polyphenol contents decreased a little in five days in May sample and March sample. I measured phenol compounds of garlic acid, vani11ic acid, caffeic acid, p-coumaric acid, ferulic acid, most of consisted in corrected forms. Fragrance components were confirmed 9 kinds in March sample, 11 kind in May sample the common components in May sample and March sample were 7-octen-4-o1.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.8-15
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• 2011

Purpose: This study evaluated the bonding strength of direct relining resin to Co-Cr denture base material according to surface treatment and immersion time. Materials and methods: In this study, Co-Cr alloy was used in hexagon shape. Each specimen was cut in flat surface, and sandblasted with $110\;{\mu}m$ $Al_2O_3$ for 1 minute. 54 specimens were divided into 3 groups; group A-control group, group B-applied with surface primer A, group C-applied with surface primer B. Self curing direct resin was used for this study. Each group was subdivided into another 3 groups according to the immersion time. After the wetting storage, shear bond strength of the specimens were measured with universal testing machine. The data were analyzed using two-way analysis of variance and Tukey post hoc method. Results: In experiment of sandblasting specimens, surface roughness of the alloy was the highest after 1 minute sandblasting. In experiment of testing shear bond strength, bonding strength was lowered on group B, C, A. There were significant differences between 3 groups. According to period, Bonding strength was the highest on 0 week storage group, and the weakest on 2 week storage group. But there were no significant differences between 3 periods. According to group and period, bonding strength of all group were lowered according to immersion time but there were no significant differences on group B and group C, but there was significant difference according to immersion time on group A. Conclusion: It is useful to sandblast and adopt metal primers when relining Co-Cr metal base dentures in chair-side.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.82-89
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• 2014

Purpose: The purpose of this study was to observe the change of viscoelastic properties of dental resin cements during polymerization. Materials and methods: Six commercially available resin cement materials (Clearfil SA luting, Panavia F 2.0, Zirconite, Variolink N, RelyX Unicem clicker, RelyX U200) were investigated in this study. A dynamic oscillation-time sweep test was performed with AR1500 stress controlled rheometer at $32^{\circ}C$. The changes in shear storage modulus (G'), shear loss modulus (G"), loss tangent (tan ${\delta}$) and displacement were measured for twenty minutes and repeated three times for each material. The data were analyzed using one-way ANOVA and Tukey's post hoc test (${\alpha}$=0.05). Results: After mixing, all materials demonstrated an increase in G' with time, reaching the plateau in the end. RelyX U200 demonstrated the highest G' value, while RelyX Unicem (clicker type) and Variolink N demonstrated the lowest G' value at the end of experimental time. Tan ${\delta}$was maintained at some level and reached the zero at the starting point where G' began to increase. The tan ${\delta}$and displacement of the tested materials showed similar pattern in the graph within change of time. The displacement of all 6 materials approached to zero within 6 minutes. Conclusion: Compared to other resin cements used in this study, RelyX U200 maintained plastic property for a longer period of time. When it completed the curing process, RelyX U200 had the highest stiffness. It is convenient for clinicians to cement multiple units of dental prostheses simultaneously.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.190-198
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• 2013

Purpose: The purposes of this study were to investigate osseointegration around zirconia implants which had machined or alumina sandblasted surface, and to compare the results with titanium implants. Materials and methods: The study was performed on the tibia of 6 pigs. Three types of implants were investigated: group T-titanium implant, group Z-machined zirconia implant, group ZS-alumina sandblasting treated zirconia implant. Zirconia implants were manufactured from yttria-stabilized tetragonal zirconia polycrystalline (Acucera Inc., Pocheon, Korea). A total of 36 implants were installed in pigs' tibias. After 1, 4 and 12 weeks of healing period, the periotest and the histomorphometric analysis were performed. The data were analyzed using one-way ANOVA and significance was assessed by the Scheffe test (${\alpha}=.05$). Results: In the measurement of surface roughness, highest Ra value was measured in group T with significant difference. No significant differences were found among groups regarding Periotest values. After 1 week, in comparison of bone to implant contact (BIC), group Z showed higher value with significant difference. In comparison of bone area (BA), group T and group Z showed higher value with significant difference than group ZS. After 4 weeks, in comparison of BIC, group T showed higher value with significant difference. Comparison of BA showed no significant difference among each implant. After 12 weeks, the highest mean BIC values were found in group T with significant difference. Group ZS showed higher BIC value with significant difference than group Z. In comparison of BA, group T and group ZS showed higher value with significant difference than group Z. Conclusion: Zirconia implant showed low levels of osseointegration in this experiment. Modification of surface structure should be taken into consideration in designing zirconia implants to improve the success rate.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.54-60
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• 2003

This study evaluated the influence of chemomechanical caries removal agent $Carisolv^{TM}$(MediTeam, Sweden) for composite resin adhesion to sound human permanent and primary dentin. The buccal/labial surfaces of 80 permanent molars and 80 primary incisors were used. Four types of adhesives and one composite resin were used; AQ Bond(Sun Medical, Japan), Clearfil SE Bond(Kuraray, Japan), Single Bond(3M, USA), Scotchbond Multi-Purpose(3M, USA) and Z100(3M, USA). One drop of $Carisolv^{TM}$(MediTeam, Sweden) was pretreated on the dentin for 0 second(control) and 60 seconds. The specimens were thermocycled for 1,000 times in baths kept 5 degrees C and 55 degrees C with a 30 seconds dwell time. Shear bond strengths were tested and the data was statistically analyzed using one-way ANOVA with subsequent post hoc Scheffe test at p<0.05. $Carisolv^{TM}$ treatment significantly decreased the shear bond strength. Shear bond strength of permanent dentin was significantly higher than that of primary dentin. Clearfil SE Bond treatment groups showed the highest shear bond strength and AQ Bond treatment groups showed the lowest shear bond strength.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.1
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• pp.72-78
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• 2009

Purpose: Bone mineral density (BMD) measurements need to be precise enough to be capable of detecting small changes in bone mass of rats. Using a regular dual-energy X-ray absorptiometry (DXA), we measured many BMD of various skeletal sites in rats to examine precision of DXA in relation to the repositioning on the bones of rats. Materials and Methods: Using DXA and small animal software, scans were performed 4 times in all 12 male rats without repositioning (Group 1a). Another four scans for 6 of 12 rats were done with repositioning between scans (Group 2). Customized regions of interest (ROIs), encapsulate the right hind limb, L1-4, skull and pelvic bones were drawn at each measurement. The precision of the measurements was evaluated by measuring the coefficient of variation (CV) of four measurements of BMD at each skeletal site of all rats with or without repositioning. Significance of differences between group 1b (six rats out of group 1a, which were come under group 2) and group2 were evaluated with Wilcoxon Signed Rank Sum Test. Results: CVs obtained at different skeletal sites of all measurements in Group 1b and 2. It was $3.51{\pm}1.20$, $ 2.62{\pm}1.20$ for the hindlimb (p=0.173), $3.83{\pm}2.02$, $4.59{\pm}2.02$ for L1-4 (p=0.600), $3.73{\pm}1.87$, $1.53{\pm}0.89$ for skull (p=0.046), and $2.92{\pm}0.60$, $1.45{\pm}0.60$ for pelvic bones (p=0.075). Conclusion: Our study demonstrates that the DXA technique has the precision necessary when used to assess BMD for various skeletal sites in rats regardless of repositioning.