• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.15-30
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• 1999

The purpose of this study was to evaluate the effect of mixed extracts of aralia cortex and phellodendron cortex (P55A) on activities of human gingival fibroblasts and periodontal ligament cells in vitro. First experiment was done to evaluate the effect of P55A in normal condition. In control group, the cells($4.5{\times}10^4$ cells/ml) were cultured with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum. In experimental groups, P55A was added to the above culture condition at the final concentrations of 0.1 ${\mu}g/ml$(Test group 1), 1 ${\mu}g/ml$(Test group 2) and 10 ${\mu}g/ml$(Test group 3). Then each group was tested for the cell proliferation rate at $\frac{1}{2}$, 2, 5 days, protein levels at 2, 5 days, and alkaline phosphatase activity at 2, 5 days. Second experiment was done to evaluate the effect of P55A in high glucose condition. 200 mg/dl glucose was added to the same culture condition of all groups in first experiment. Then each group was tested for the cell proliferation rate at $\frac{1}{2}$ , 2, 5 days, protein levels at 2, 5 days, and alkaline phoaphatase activity at 2, 5 days. The results were as follows ; 1. First experiment 1) As P55A concentration increased, cell proliferation rate increased significantly in test group 2 at 2 days, and test group 2 and 3 at 5 days in human gingival fibroblasts and periodontal ligament cells(P<0.05). 2) In human gingival fibroblasts, all test groups showed significantly increased protein levels as compared to control group at 5 days. In periodontal ligament cells, test group 2 and 3 showed significantly increased protein levels as compared to control group at 2, 5 days(P<0.05). 3) Alkaline phosphatase activity of human periodontal ligament cells increased as P55A concentration increased. The test group 2 and 3 showed significant increase as compared to control group at 5 days(P<0.05). 2. Second experiment 1) As P55A concentration increased, cell proliferation rate increased significantly in test group 2 at 2 days, and test group 2 and 3 at 5 days in human gingival fibroblasts and periodontal ligament cells(P<0.05). 2) In human gingival fibroblasts, test group 3 showed significantly increased protein levels as compared to control group at 2 days, and all test groups at 5 days. In periodontal ligament cells, test group 2 and 3 showed significantly increased protein levels as compared to control group at 2, 5 days(P<0.05). 3) Alkaline phosphatase activity of human periodontal ligament cells increased as P55A concentration increased. The test group 2 and 3 showed significant increase as compared to control group at 2 days, and all test groups at 5 days(P<0.05). From the above results, mixed extracts of aralia cortex and phellodendron cortex appeared to enhance cellular activities including cell proliferation rate, protein levels and alkaline phosphatase activity of human gingival fibroblasts and periodontal ligament cells in normal and high glucose condition. This study suggests that mixed extracts of aralia cortex and phellodendron cortex seem to be able to subside the inflammation of periodontal tissue and regenerate the destructed periodontal tissue.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.446-460
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• 2000

All-ceramic restorations have had a more limited life expectancy than metal ceramic crowns be-cause of their lower strength. The relatively lower strength has limited the use of all-ceramic crowns to the areas where occlusal loads are lower Therefore many researches have been done to increase the strength of all-ceramic crowns. IPS Empress 2 is a new type of lithium disilicate glass-ceramic with enhanced physical characteristics which has been in use clinically since 1998. Previous researches reported that the flexural strength of all-ceramic material was greater than 300 MPa, and all-ceramic crowns can be used in staining or layering technique. The objective of this study was to investigate the influence of the thickness of IPS Empress 2 ceramic on fracture strength. Both staining technique and layering technique was investigated. Vita VMK was used as control. For all three groups, five specimens each of 0.8mm, 1.0mm, 1.4mm, 1.8mm, and 2.2mm thick-ness (a total of 75 specimens) were prepared. Control group : Vita VMK Porcelain specimens were prepared with dentine ceramic and liquid glazing was done. Group I : IPS Empress 2 were prepared with staining technique and stained twice and glazed once. Group II : IPS Empress 2 were prepared with layering technique and glazed after wash firing. The thickness and diameter of the specimen were measured and controlled after specimen preparation. Biaxial Flexure Test (ASTM Standard F394-78) was adopted as this test method produces results least affected by the edge condition of the specimens. Fracture strength was measured with Instron Universal Testing Machine. Conclusions are as follow : 1. The fracture strength was increase in order of control group, test group I, test group II. 2. Fracture strength of the group I (Empress 2 Staining) was 65.54 N in 0.8mm, 155.2 N in 1.0mm, 233.5 N in 1.4mm, 434.5 N in 1.8mm, and 600.1 N in 2.2mm. 3. Fracture strength of the group II (Empress 2 Layering) was 190.0 N in 0.8mm, 283.5 N in 1.0mm. 437.2 N in 1.4mm, 732.0 N in 1.8mm, and 1115.0 N in 2.2mm. 4. No statistical difference was found in flexural strengths according to thickness in a specified group(p>0.05).

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.175-180
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• 2001

Purpose : Recently in Korea since 1998, 2TU has been used instead of 5TU, which caused a confusion in interpreting tuberculin skin tests. We compared the tuberculin skin reaction to PPD(purified protein derivatives) 1TU, 2TU and 5TU. Methods : We studied tuberculin skin reaction to PPD 1TU, 2TU and 5TU on 92 infants who were vaccinated with percutaneous multiple puncture BCG vaccine(Tokyo 172 strain, Japan BCG Laboratory Co.) in neonatal period. Diameters of indurations were measured in millimeters 48~72 hours after the intradermal injection of PPD 1TU, 2TU and 5TU. Results : Among 92 infants(male : 56, female : 36), 1TU was used on 31 infants, 2TU on 31 infants and 5TU on 30 infants for tuberculin skin test. The mean diameter of induration for PPD 1TU, 2TU and 5TU were $5.7{\pm}4.2mm$, $7.1{\pm}3.7mm$, and $9.2{\pm}4.2mm$, respectively. There was no statistical difference in mean diameter of induration between 1TU and 2TU. However, when tested with 5TU, the diameter of induration was significantly larger than those of PPD 1TU and 2TU(P<0.05). Six subjects(19.4%) tested with 1TU, 9 subjects(29%) tested with 2TU and 16 subjects(53.3%) tested with 5TU had diameter of 10 mm or more. There was no statistical difference between 1TU and 2TU but for 5TU, number of subjects with diameter of 10 mm or more was significantly higher than PPD 1TU and 2TU(P<0.05). Number of subjects with induration diameter of 5 mm or more for 1TU, 2TU and 5TU was 19(61.3%), 22(71.0%) and 26(86.7%), respectively. However, there was no statistical difference. Conclusion : A new standard criteria for interpreting the tuberculin skin test with PPD 2TU should be established for clinical diagnosis of tuberculosis.

• Korean Journal of Animal Reproduction
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• v.8 no.1
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• pp.22-28
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• 1984

This experiment was carried out to investigate effects of DMSO or ethylene glycol as a cryopotectant and of freezing methods on survival rate of forozen-thawed rat 2-cell embryos by morphological observation. 2-cell embryos were recovered from oviducts of Sprague Dawley females mated with males of same strain on day 2 of pregnancy after inducing superovulation by intrapertioneal injection of PMSG and HCG. In slow freezing and thawing groups, embryos were frozen to -79$^{\circ}C$ or -196$^{\circ}C$ in a glass test tube containing 0.2ml PBI with 1.5M DMSO or 1.2M ethylene glycol at a rate of 0.3-1.0C/min. and thawed slowly. When samples were frozen to -79$^{\circ}C$, higher survival rate was obtained in the medium containing DMSO (43.9%) than ethylene glycol (41%). And similar result was obtained (32.5% in DMSO vs. 31.4% in ethylene glycol) when samples were frozen. In rapid freezing and thawing groups, embryos were frozen to -79 or -196$^{\circ}C$ in a glass test tube containing 0.2ml of PBI with 1.5M DMSO or 1.2M ethylene glycol by rapid cooling, and thawed rapidly. When samples were frozen to -79$^{\circ}C$, 1.5M DMSO (13.2%) was more effective than 1.2M ethylene glycol (6.1%). When the storage temperature was -196$^{\circ}C$, survival rates were 9.8% in 1.5M and 5.4% in 1.2M ethylene glycol.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.2
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• pp.82-94
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• 1988

The purpose of this study is to introduce the Double Punch test method which is an indirect testing method of tensile strength of concrete, and to compare with the tensile strength of concrete as determined by the split-cylinder test, a practical method for performing the Double Punch test to obtain the tensile strength of concrete is proposed and recommended for general use. In this study, the dimensions of cylindrical specimens used in the Double-Punch test were 15X30cm, 15X15cm, 10${\times}$(20cm, and 5${\times}$l0cm, and in the split-cylinder test were 15${\times}$(30cm, 15${\times}$(15cm, and 10${\times}$(20cm. And the diameters of loading punches used in the Double-Punch test were 1.5cm, 2.5cm, and 3.5 cm. The results obtained from tests are summarized as follows ; 1. In the split-cylinder test, the tensile strength of concrete by the linear elasticity theory is similar to that of plasticity theory. 2. Both split-cylinder test and Double-Punch test, tensile strength of concrete is increased with decreasing specimen size. This tendency is identical when the ratio of specimen diameter to height is 1: 2, but that tendency is quite different when the ratio is 1: 3. In the Double-Punch test, if specimen size is constant, by increasing the punch size, tensile strength of concrete is increased, too. 4. Using a 15 ${\times}$( 15 cm cylinder specimen and 3.5 cm diameter punch in the Double Punch test would give the most uniform and consistent result in tensile strength, and the result showed a gQod correlation with splitting tensile strength from 15 x 30cm specimen. 5. In order to obtain satisfactory results and to nuninuze variability, it is proposed that specimens of 15 cm in diameter and 15 cm in height with two 3.5 cm diameter punches should be used. It seems, therefore, reasonable tt) take f't=0.0024 P(kg / cm$^2$) as a working formula for computing the tensile strength in the Double Punch test for concrete.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.3
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• pp.140-148
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• 1992

The effect of mechanical, properties in the plastic zone near the crack-tip was investigated, under various controlled loading conditions, i.e., ${\Delta}K$ increasing, ${\Delta}K$ decreasing, and single overload test. For both ${\Delta}K$ decreasing test and ${\Delta}K$ increasing test with constant stress ratio, it is found that the ratio of material constant m'( ${\Delta}K$ decreasing test) to material constant m( ${\Delta}K$ increasing test) is larger than 1 for n<0.1, and it is equal to 1 for 0.10.2. A modified crack growth rate equation based on Forman's equation which applied stable region of fatigue crack propagation in ${\Delta}K$ decreasing test is proposed. Within the limit of this single overload test, an empirical relation between among the retardation ratio (Nd/ $N^{*}$), the strain hardening exponent (n) and the percent peak load (%PL) has been established.established.

• The Journal of the Korean dental association
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• v.16 no.12 s.115
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• pp.941-944
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• 1978

The author studied skin reactions and their incidences among 100 dental students and dental nurses to 2% Lidocaine HC1, 3% H₂O₂, Euginol, 5% Sodium Hypochlorite, Dycal and Adhesive plaster by means of Patch test. Following are the results of the study. 1. Eighty six cases out of 100 revealed slight response to 1 or 2 allergens. 2. 2% Lidocaine HC1 showed 1 case, 3% H₂O₂cases, Euginol 2 cases, 5% Sodium Hypochlorite 74 cases, Dycal 1 case Adhesive plaster 8 cases. 3. 5% Sodium Hypochlorite was the most influential to skin. 32 cases showed grade 1+, 20 cases showed grade 2++, 16 cases showed grade 3+++, 6 cases showed grade 4++++,

• Journal of Biosystems Engineering
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• v.31 no.4 s.117
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• pp.349-354
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• 2006

This study was performed to evaluate the performances for a concurrent flow rice dryer of pilot scale with devices for circulating rice. The pilot scale dryer with the capacity of 700 kg was developed to obtain design informations for the development of actual scale dryer of holding capacity of 10 tons. Three drying tests were conducted at two temperature levels of $100^{\circ}C\;and\;120^{\circ}C$, and two air flow rates levels of $28.5cmm/m^2\;and\;57.1cmm/m^2$. Drying conditions for Test-1, Test-2 and Test-3 were $100^{\circ}C\;-28.5cmm/m^2,\;120^{\circ}C-28.5cmm/m^2\;and\;120^{\circ}-57.1cmm/m^2}$ respectively. Drying rates were 0.73%(w.b./h) for Test-1, 0.90%(w.b./h) for Test-2 and 1.46%(w.b./h) for Test-3. The crack ratios of brown rice after drying ranged from 2.4% to 8.4%, and increased with the increase of drying rate and airflow rate. The energy consumptions were from 6,225 kJ/kg to 6,993 kJ/kg which was higher than that of conventional cross-flow rice circulating type dryer used in Korea. This results were due to the lower ambient air temperatures of $4.5^{\circ}C\;to\;13.4^{\circ}C$ during drying tests.

• Journal of Pharmacopuncture
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• v.5 no.1 s.8
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• pp.27-42
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• 2002

Objective: The purpose of this study was to investigate the acute and subacute toxicity and sarcoma- 180 anti-cancer effects of Herbal acupuncture with Triglii Semen in mice and rats. Method: Balble mice were injected intraperitoneally with Triglii semen Herbal acupuncture for $LD_{50}$ and acute toxicity test. Sprague Dawley rats were injected intraperitoneally with Triglii semen Herbal acupuncture for subacute toxicity test. The Triglii semen Herbal acupuncture was injected on Chung-wan(CV12) of mice with S-180 cancer cell line. Results: 1. In acute toxicity test, the $LD_{50}$ value was $7.49{\times}10^3$ml, 0.30ml/kg.2. The body weights of mice treated with Triglii semen Herbal acupuncture increased during the acute toxicity test. 3. In acute toxicity test of serum biochenrical values of mice, total protein was decreased in treatment groups I, 2 and 3, albunrin was decreased in treatment groups 2 and 3 compared to the control group. GOT was increased in treatment group I and Alk. Phosphatase was increased in treatment groups 1,2 and 3 compared to the normal group(p<0.05). 4.ln subacute toxicity test, severe tissue injury was found in lung and liver. 5. In subacute toxicity test, the body weight was decreased in treatment groups I and 2 compared to the normal group and the weight of liver. lung and kidney were increased in treatment groups 1, 2 and 3 compared to the normal group.(p<0.05) 6. In subacute toxicity test, RBC, HGB and HCT were decreased in treatment groups 1 and 2 compared to the normal group. MCV was increased in treatment group1 compared to the normal group, MCH was increased in treatment groups 1 and 2 compared to the control group in complete blood count test.(p<0.05) 7. In subacute toxicity test, total protein was decreased in treatment groups 1 and 2 compared to the nonnal group, BUN was increased in treatment groups 1 and 2 compared to the nonnal group, creatinine and uric acid were decreased in treatment groups 1 and 2 compared to the normal group, glucose was increased in treatment group 2 compared to the nonnal group, triglycelide was decreased in treatment groups I and 2 compared to the normal group, total cholesterol was increased in treatment groups 1 and 2 compared to the control group. GOT was decreased in treatment group 2 compared to the normal and control group, AIk. Phosphatase was increased in treatment group 1 compared to the normal and control group.(p<0.05) 8. Median survival time was 17days in treatment group 2 for S- 180 cancer cell treated with Triglii semen Herbal acupuncture. 9. Natural killer cell activity was insignificant for S-180 cell treated with Triglii semen Herbal acupuncture.(p<0.05) 10. lnterieukin-2 productivity was decreased for S-180 cell treated with Triglii semen Herbal acupuncture compared to the normal and control group.(p<0.05) Conclusion: According to the results, we can conclude Herbal-acupuncture with Triglii semen caused toxicity, and caused no effects in S-180 cancer cell.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.337-343
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• 1993

To determine the test conditions to enhance the use of hamster test in dogs, semen were collected from four dogs which had been proven to be fertile in the past and then preserved in BWW (Biggers, Whitten, Whittingham) medium for about 20 hours. The semen were given each different treatment according to the experimental design and coincubated with zona-free hamster ova for 5 hours. The ova were stained by lacmoid and examined under phase contrast microscope to investigate the rates of ova bound with sperm(sperm binding) and ova penetrated by sperm (penetration), and also numbers of both bound and penetrated sperm per ovum. In comparison of different concentrations of canine sperm, the rate of sperm binding was higher in $1.5{\times}10^8$, $1{\times}10^8$, and $5{\times}10^7$ sperm concentrations than $5{\times}10^5$ concentration(p<0.01), and also than $5{\times}10^6$ concentration(p<0.05), respectively. The number of bound sperm per ovum was considerably higher in $1.5{\times}10^8$ sperm concentration than $5{\times}10^7$, $1.5{\times}10^6$, and $5{\times}10^5$ concentrations(p<0.01). The rate of penetration was considerably higher in $1.5{\times}10^8$ and $1{\times}10^8$ sperm concentrations than $5{\times}10^5$ concentration,(p<0.01), and also the higher result of penetration was shown in $5{\times}10^7$ than $5{\times}10^5$ (p<0.05). The number of penetrated sperm per ovum was considerably higher in $1.5{\times}10^8$ sperm concentrations than $5{\times}10^5$(p<0.01), and also the higher number was shown in $1{\times}10^8$ than $5{\times}10^5$ (p<0.05). In comparison of the different preincubation period of canine spermatozoa, no difference was obtained in the results of hamster test among the preincubation periods of 4 hours, 18~24 hours and 48 hours. The canine spermatozoa in BWW medium with $Ca^{2+}$(1.3mM) and without FCS(fetal calf serum), with both $Ca^{2+}$(1.3mM) and FCS, with $Ca^{2+}$(2.6mM) and without FCS, and with both $Ca^{2+}$(2.6mM) and FCS showed no difference in the results of hamster test.These results indicated that the appropriate concentration of sperm should be given in hamster test for dog sperm.