• The Journal of Korean Academy of Prosthodontics
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• v.45 no.6
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• pp.753-759
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• 2007

Statement of problem. In distal extension removable partial denture, the preservation of health of abutment teeth is very important, but abutment teeth are subjected to unfavorable stress under unilateral loading specially. Purpose. The purpose of this study was to investigate the biomechanical effects of mandibular removable partial dentures with various prosthetic designs under unilateral loading, using strain gauge analysis. Material and methods. Artificial teeth of both canines were anchored bilaterally in a mandibular edentulous model made of resin. Bilateral distal extension removable partial dentures with splinted and unsplinted abutments were fabricated. Group 1: Clasp-retained mandibular removable partial denture with unsplinted abutments Group 2: Clasp-retained mandibular removable partial denture with splinted abutments by 6-unit bridge. Group 3: Bar-retained mandibular removable partial denture Strain gauges were bonded on the labial plate of the mandibular resin model, approximately 2 mm dose to the abutments. Two unilateral vertical experimental loadings (30N and 100N) were applied subsequently via miniature load cell that were placed at mandibular left first molar region. Strain measurements were performed and simultaneously monitored from a computer connected to data acquisition system. For within-group evaluations, t-test was used to compare the strain values and for between-group comparisons, a one-way analysis of variance (ANOVA) was used and Tukey test was used as post hoc comparisons. Results. The strain values of group 1 and 2 were tensile under loadings. In contrast, strain values of group 3 were compressive in nature. Strain values increased as the applied load in increased from 30N to 100N (p<.05) except for right side in group 1. Under 30N loading, in left side, group 1 showed higher strain values than groups 2 and 3 in absolute quantity (p<.05). And group 2 showed higher strain values than group 1 (p<.05). In right side, group 1 and 2 showed higher strain values than group 3 in absolute quantity (p<.05). Under 100N loading in left side, group 1 showed higher strain values than groups 2 and 3 in absolute quantity (p<.05). And group 2 showed higher strain values than group 1 (p<.05). In right side, group 1 and 2 showed higher strain values than group 3 in absolute quantity (p<.05). Under 30N loading, group 2 and 3 showed higher strain values in right side than in left side. Under 100N loading, right side strain values were higher than left side ones for all groups. Conclusion. Splinting of two isolated abutments by bridge reduced the peri-abutment strain in comparison with unsplinted abutments under unilateral loading. Bar-retained removable partial denture showed the lowest strain of three groups, and compressive nature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1551-1558
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• 2009

The management of skeletal health in the twenties is the number one priority for preventing fracture or osteoporosis occurrence in later life cycle. Therefore, the factors influencing bone mineral density were examined by anthropometric measurements, food intakes, bone mineral density and biochemical nutritional indexes in blood among college students. Among the students who received health examinations from May to December, 2007, 532 male and 507 female students who agreed to participate in the study were selected. Nutritional intakes were estimated with 3-day 24-hour recall method. Bone mineral density was measured by ultrasonic attenuation passing through right calcaneus bone and expressed as broadband ultrasound attenuation and t-score was calculated by WHO criteria. Red blood cell count, hemoglobin, hematocrit values were measured by whole blood analysis, and alkaline phosphatase, serum calcium and serum iron were used as indexes for biochemical nutritional status. Data analysis was conducted using SPSS 14.0 program, and protecting and risk factors on bone health status were analyzed by logistic regression analysis between normal bone health group (t-score$\underline{\geq}$ -1.0) and osteopenia group (t-score<-1.0). The results showed that more people belong to the normal bone health group probably because this study was conducted among those with their peak bone density. Biochemical nutritional status and nutrition intakes of both groups for normal and osteopenia did not show statistically significant difference except MCHC, animal protein and animal iron intakes in female. According to the results of logistic regression analyses, dietary intakes of animal protein, animal iron and zinc showed protecting effects against osteopenia. Therefore, dietary nutritional intakes of micronutrients, especially iron and zinc are important for bone health of young people.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.93-101
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• 2014

Asymmetric 1,2-distearoyl-3-oleoyl-rac-glycerol (SSO) triacylglycerol (TAG) is used as a cocoa butter replacer (CBR). In this study, it was produced by lipase-catalyzed interesterification of fully hydrogenated soybean oil (FHSBO) and oleic ethyl ester (OEE) in a batch type reactor at $75^{\circ}C$, 250 rpm. Different molar ratios (FHSBO : OEE=1:1, 1:2 and 1:3, w/w) and various reaction times (1, 2, 3, 4, and 5 hr) were also tested. The optimized condition for SSO was a FHSBO : OEE molar ratio of =1:1 at reaction times of 2, 3, 4, and 5 hr. Enzymatic synthesis generated SSO/SOS, as well as the other TAGs (e.g., PSO/POS, SOO/OSO, SSS), ethyl esters, monoacylglycerol (MAG), and diacylglycerol (DAG). After scale-up, fractionation by solvent (methanol and acetone) fractionation and column chromatography was applied. To reduce ethyl esters, high-melting TAGs (e.g., SSS), and SOO/OSO in reactants, solvent fractionation was applied. Using a silica gel column (sample : silica gel=2:1, wt%), MAG and DAG were removed at $25^{\circ}C$. The major fatty acid composition of the final products (with a high SSO/SOS content) was palmitic acid (C16:0, 10.9~12.9 area%), stearic acid (C18:0, 52.2~54.9 area%), and oleic acid (C18:1, 34.2~35.5 area%). In reversed-phase HPLC analysis, the major TAG species of the final product (FHSBO : OEE=1:1, 2 hr) were SSO/SOS (82.31 area%) and PSO/POS (14.51 area%). Based on the $[SS]^+$ : $[SO]^+$ ratio obtained by RP-HPLC/APCI-MS, the final product had a higher SSO (AAB type TAG) content than cocoa butter (CB). The solid fat index (SFI) of CB and the final product obtained were similar with a narrow melting point range around ~32 to $35^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.600-607
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• 2017

The total acidity (TA) of Makgeolli was affected by suspended solids and $CO_2$ produced during the fermentation process. Nine Makgeollis (four sterilized and five unsterilized Makgeollis) were collected in the market, and their TAs were compared before and after filtration and $CO_2$ removal. TAs of sterilized Makgeollis were 0.379~0.477%, which significantly decreased to 0.167~0.225% after filtration and 0.132~0.170% after $CO_2$ removal (P<0.05). TAs of unsterilized Makgeollis were 0.412~0.467% and decreased to 0.157~0.365% after filtration and 0.143~0.280% after $CO_2$ removal (P<0.05). TAs of Makgeollis were compared by three methods using different indicators. The TAs of sterilized and unsterilized Makgeollis were 0.105~0.123% and 0.105~0.200%, respectively, by bromthymol blue+neutral red (light green), 0.129~0.154% and 0.130~0.255%, respectively, by phenolphthalein (faint pink), and 0.120~0.146% and 0.130~0.232%, respectively, by bromthymol (blue). Nowadays, Makgeolli is commercialized with various distinct colors, and thus it is important to select appropriate indicators for proper titration endpoint identification for TA measurement. The compositions of organic acids profiles varied depending on sterilized or unsterilized Makgeollis, in which oxalic acid (0.108~0.329 mg/mL), malic acid (ND to 0.134 mg/mL), lactic acid (0.127~0.776 mg/mL), and citric acid (ND to 1.159 mg/mL) were found, and lactic acid was in unsterilized more than sterilized Makgeollis.

• Journal of Gastric Cancer
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• v.5 no.1
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• pp.40-46
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• 2005

Purpose: Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms of the gastrointestinal tract. GISTs are positive for the expression of c-Kit protein at immunohistochemistry, and their clinical presentations vary. This retrospective study was performed to evaluate the clincopathologic characteristics of GISTs and to define the prognostic factors. Materials and Methods: 40 patients who underwent a complete resection of a GIST during the period $1996\~2003$ at the Department of Surgery, Korea University College of Medicine, were studied. We divided them into low- and high-risk. groups by using tumor size and mitotic count: 23 cases were low risk, and 17 were high risk. Clinicopathologic features, immunohistochemical findings, and prognoses were compared between the low- and the high-risk groups. Results: The mean age of the 40 patients was $61.3\pm11.1$years, and the male-to-female ratio was 1：1.1. There was no significant difference in age and sex between the groups. A comparative analysis revealed tumor size, mitotic count, clinical symptoms, preoperative pathologic diagnosis, ulceration, and necrosis to be variables that had statistically significant differences between the high- and the low-risk groups. In the univariate analysis, tumor size, mitotic count, ulceration, necrosis, and abnormal endoscopic ultrasound findings were associated with disease-free survival, but in the multivariate analysis, mitotic activity was the only independent factor associated with disease-free survival. 8 patients had recurrences during the follow-up period, and four of them were treated with STI-571 (imatinib mesylate, $Gleevec^{(R)}$). The treated patients have survived until now; however, two of non-treated patients died from disease progression. Conclusion: Based on this study, tumor size, ulceration, and necrosis are significant factors affecting survival, and mitotic activity may be a useful prognostic marker. STI-571 may be used in an adjuvant setting because the drug has shown anticancer activity in patients with recurrence or metastasis.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.174-179
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• 2005

Purpose: The 5-year survival rate is the most useful parameter for evaluating the effect of management on most malignant tumors. Recurrence after a curative resection for gastric cancer occurs mostly within 3 years of the operation, which caused us to evaluate whether a 3-year disease-free survival (3DFS) can be substituted for a 5-year overall survival (5OS). Materials and Methods: We reviewed the medical records of 656 consecutive patients who had undergone a curative resection for gastric cancer To assess whether 3DFS represents 5OS, we used a simple linear regression with survival probability calculated by using the survival function. Results: Recurrence was found in 175 cases during the follow-up periods. The accumulative frequencies of recurrence at postoperative 1 year, 3 years, and 5 years were 46% (81 cases), 89% (156 cases), and 97% (170 cases), respectively. The correlation coefficient (r) and the coefficient of determination $(r^2)$ between 3DFS and 5OS were 0.87 and 0.76, respectively, and the regression equation was $5OS=0.18+(0.80{\times}3DFS)$. The r and $R^2$ according to the type of recurrence were 0.89 and 0.80 in peritoneal seeding, 0.88 and 0.78 in hematogeneous metastasis, and 0.86 and 0.73 in local recurrence, respectively. The r (0.77) and $r^2$ (0.60) were relatively lower in low stages (stage I and II) compared to r (0.88) and $r^2(0.77)$ in high stages (stage III and IV). Conclusion: The 3DFS is an excellent predictor of 5OS. Therefore, if we use the former as the treatment evaluating method, 2-year time reduction in assessing and reporting treatment results is expected.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.200-205
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• 2005

Purpose: KLF4, a member of the KLF family, is a zinc finger tumor suppressor protein that is critical for gastric epithelial homeostasis. Our aim was to determine whether the altered expression of KLF4 might be associated with gastric cancer development and, if so, to determine to which pathologic parameter it is linked. Materials and Methods: For the construction of the gastric cancer tissue microarray, 84 paraffin-embedded tissues containing gastric cancer areas were cored 3 times and transferred to the recipient master block. The expression pattern of KLF4 was examined on tissue microarray slides by using immunohistochemistry and was compared with pathologic parameters, including histologic type, depth of invasion, lymph node metastasis, and peritoneal dissemination. Results: The KLF4 protein was expressed in cytoplasm and nucleus of superficial and foveolar epithelial cells in the normal gastric mucosa. We found markedly reduced or loss of KLF4 expression in 43 (51.2%) of the 84 gastric cancer tissues. There was no significant correlation between KLF4 expression and pathologic parameters, including histologic type, depth of invasion, lymph node metastasis and peritoneal dissemination. Conclusion: Our findings suggest that altered expression of KLF4 may contribute to abnormal regulation of gastrointestinal epithelial cell growth and differentiation and to the development of Korean gastric cancer, as an early event.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.478-485
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• 2013

"GukMinSoHakDokBon", published in 1895, is the first national textbook designated by the Education Institute. Ten of the 41 chapters consist of scientific contents. In this thesis, some the contents are reviewed in detail and studied to see what significance it has in view of science education. The scientific contents described in "GukMinSoHakDokBon" include Plants Change, Clock, Camels, Wind, Hive, Respiration, Crocodiles, Nature of Animals, and Chemical Elements. For that kind of diversity, it was told that "GukMinSoHakDokBon" was not considered for normal students, and there were many ambiguities due to in sufficient explanations. Some of the contents were even technically wrong. So it has been noted that the scientific contents of "GukMinSoHakDokBon" have more significance in providing new information at that time but not in understanding newly-organized scientific knowledge. However, it is obvious that the early science education in Korea is composed of the methods of reading "GukMinSoHakDokBon". This is a common figure, which can be found in "Willson's Reader", the elementary reading textbook in the U.S. in the 1860's or "小學讀本" by the Ministry of Education in Japan. One thing remarkable is "GukMinSoHakDokBon" induced students' interests through the use of storytelling method for introducing some unfamiliar scientific knowledge. There is no doubt that "GukMinSoHakDokBon" has a very positive role in increasing students interest and intelligence. These advantages are being actively applied in the present model of storytelling education these days. Therefore, "GukMinSoHakDokBon" can be regarded as both a language textbook and an early figure in science education, and it can be also considered that "GukMinSoHakDokBon" has a significance not only in approaching scientific substances theoretically but in using storytelling methods to deliver unfamiliar and strange knowledges to students.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.4
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• pp.235-249
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• 2002

This study was accompolished to analyze and compare the number and area of the occlusal contact points in healthy volunteers and athletes with normal occlusion. Before the study, 89 athletes(sports career:8.6 years, average age 20) at Kyung Hee University were selected, and survey was accomplished for athlete's recognition about sports dentistry. For this study, 15 athletes(13 amles and 2 females with average age 20) and 21 healthy volunteers(14 mles and 7 females with average age 20.09) at Kyung Hee University were selected. The visual display acquired by scanning of occlusal record in maximal intercuspation was converted into 16 gray value image. Then, using computer program(J & Lee Occlusal Analyser), the pixel which was in definite range of the gray value was recognized, and the numbers of recognized pixel were calculated to area. The results were as follows : (1) On the survey about sports dentistry, 28% of 89 athletes didn't agree that human occlusion may be important, and 30% didn't have any idea of the influence of human occlusion during their sports activities. (2) The average numbers of total occlusal contact points were 31.05 in control group, and 34.67 in athlete group. The average area of total occlusal contacts was $100.25mm^2$ in control group, and $127.78mm^2$ in athlete group. (3) In control group, the average numbers of occlusal contact points were revealed in order as follows; the first molar(8.48), the second molar(8.24), the second premolar(4.71), the lateral incisor(2.90), the first premor(2.43), the central incisor(2.19), and the canine(2.1). The least average in canine(2.1) was similar to the average(2.19) in central incisor and (2.09) in lateral incisor. In athlete group, the average numbers of occlusal contact points were revealed in order as follows; the first molar(8.87), the second molar(8.47), the second premolar(5.60), the canine(3.80), the lateral incisor(3.33), the first premolar(2.67), and the central incisor(1.93). (4) In control group, the average areas of occlusal contact surface were revealed in order as follows; the first molar($39.47mm^3$), the second molar($37.54mm^3$), the second premolar($9.54mm^3$) the first premolar($6.18mm^3$), canine($3.49mm^3$), the central incisor($2.76mm^3$), and the lateral incisor($1.28mm^3$). In athlete group, the average areas of occlusal contact surface were revealed in order as follows; the first molar($44.11mm^3$), the second molar($40.69mm^3$), the second premolar($16.50mm^3$), the first premolar($9.39mm^3$), the canine($5.08mm^3$), the lateral incisor($3.7mm^3$), and the central incisor($2.25mm^3$). (5). With aging in both control and athlete group, there was a decreasing tendancy in average number of occlusal contact point, and was an increasing tendancy in average area of occlusal contact surface. In comparison at each age, both the numbers and area of occlusal contact were greater in athlete group than in control group. It was not significant in the numbers of occlusal contact points beween athlete and control group(p>0.1), but significant in the area of occlusal contact surface(p<0.05). (6) In comparision as to the kind of sports(Gymnastics:2, Rugby:3, Soccor:5, Ice hocky:5), the numbers of occlusal contact points were the most in ice hocky, and the area of occlusal contact surface was the greatest in gymnastics. With increasing a career in athlete group, there was a decreasing tendancy in average numbers of occlusal contact points, and was an increasing tendancy in average area of occlusal contact surface.

• Sleep Medicine and Psychophysiology
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• v.8 no.2
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• pp.121-128
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• 2001

Objectives: In narcoleptic patients diagnosed with ICSD (international classification of sleep disorders, 1990) criteria, nocturnal polysomnography, and MSLT (multiple sleep latency test), we tried to find characteristic features of quantitative electroencephalography (QEEG) in a wakeful state. Methods: We compared eight drug-free narcoleptic patients with sex- and age-matched normal controls, using computerized electroencephalographic mapping technique and spectral analysis. Absolute power, relative power, interhemispheric asymmetry, interhemispheric and intrahemispheric coherence, and mean frequency in each frequency band (delta, theta, alpha and beta) were measured and analyzed. Results: Compared with normal controls, narcoleptic patients showed decrease in monopolar interhemispheric coherence of alpha frequency bands in occipital ($O_1/O_2$), parietal ($P_3/P_4$), and temporal ($T_5/T_6$) areas and beta frequency band in the occipital ($O_1/O_2$) area. Monopolar intrahemispheric coherences of alpha frequency bands in left hemispheric areas ($T_3/T_5$, $C_3/P_3$ & $F_3/O_1$) decreased. Decrease of monopolar interhemispheric asymmetry of delta frequency band in the occipital ($O_1/O_2$) area was also noted. The monopolar absolute powers of beta frequency bands decreased in occipital ($O_2,\;O_z$) areas. Conclusion: Decreases in coherences of narcoleptic patients compared with normal controls may indicate fewer posterior neocortical interhemispheric neuronal connections, and fewer left intrahemispheric neuronal connections than normal controls in a wakeful state. Therefore, we suggest that abnormal neurophysiological sites of narcolepsy may involve complex areas such as neocortex and subcortex as well as the brainstem.