• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.640-658
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• 1996

The purpose of this study was to examine the mechanism of improving acid resistance of Nd-YAG laser irradiated tooth enamel and determine the most effective energy density for improving acid resistance. The bovine tooth enamel were lased with a pulsed Nd-YAG laser. The energy densities of exposed laser beam were varied from 10 to $70\;J/cm^2$. To investigate the degree of improving acid resistance by irradiation, all the samples were submerged to demineralize in 0.5 N $HClO_4$ solution for 1 minute. After 1 minute, 0.05 % $LaCl_3$ was added to the solution for interrupting the demineralization reaction. The amounts of dissolved calcium and phosphate in the solution were measured by using an atomic absorption spectrophotometer and the UV/VIS spectrophotometer, respectively. To examine the mechanism of improving acid resistance, X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy were taken. The X-ray diffraction pattern of the samples were obtained in the $10^{\circ}{\sim}80^{\circ}2{\theta}$ range with $Cu-K{\alpha}$ radiation using M18HF(Mac Science Co.) with X-ray diffractometer operating at 40 KV and 300 mA. The infra-red spectra of the ground samples in 300 mg KBr pellets 10 mm diameter were obtained in the $4000cm^{-1}\;to\;400cm^{-1}$ range using JASCO 300E spectrophotometer. The scanning electron microscopy was carried out using JSM6400(JEOL Co.) with $500{\sim}2000$ times magnification. The results were as follow 1. The concentration of calcium dissolved from laser irradiated enamel with $50J/cm^2$ was significantly lesser than that of unlased control group (p<0.05) 2. From the result of the X-ray diffraction analysis, $\beta$-TCP, which increases acid solubility, was identified in lased enamel but the diffraction peaks of (002) and (004) became sharp with increasing energy density of laser irradiation. This means that the crystals in lased samples were grown through the c-axis and subsequently, the acid solubility of enamel decreased. 3. The a-axis parameter was slightly increased by laser irradiation, whereas the c-axis parameter was almost constant except for a little decrease at $50J/cm^2$. 4. In the infra-red spectra of lased enamels, phosphate bands ($600{\sim}500cm^{-1}$), B-carbonate bands (870, $1415{\sim}1455cm^{-1}$), and A-carbonate band ($1545cm^{-1}$) were observed. The amounts of phosphate bands and the B-carbonate bands were reduced, on the other hand, the amount of the A-carbonate band was increased by increase the energy density. 5. The SEM experiments reveal that the surface melting and recrystallization were appeared at $30J/cm^2$ and the cracks were observed at $70J/cm^2$. From above results, It may be suggested that the most effective energy density for improving acid resistance of tooth enamel with the irradiation of Nd-YAG laser was $50J/cm^2$. The mechanism of improving acid resistance were reduction of permeability due to surface melting and recrystallization of lased enamel and reduction of acid solubility of enamel due to decrease of carbonate content and growth of crystal.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.566-572
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• 1992

Proximate composition and the contents of free sugars, minerals, fatty acids, amino acids and in vitro digestibility of mixed pollen load were analyzed. The protein in pollen load per 100g was 25.2g, lipid 5.4g, non-fibrous carbohydrate 50.0g and fiber 10.4. Free sugars in pollen load, as dry basis g per 100g, was fructose 26.6g, glucose 13.1g, sucrose 0.2g, maltose 1.3g, melezitose 0.02g and F/G ratio was 2.0. The content of mineral in pollen load was in the order K > P > Mg > Ca > Fe > Na > Mn > Zn > Cu. Unsaturated fatty acid of pollen load was about 69.1% and polyunsalturated fatty acid being about 50.3%. The ratios of SFA : MUFA : PUFA and PUFA : SFA were 0.61 : 0.37 : 1.00 and 1.63 respectively. The total amino acid contained in pollen load 22,337.5mg/100g and total essential amino acid was 39.2% of the total amino acid. proline was the most abundant amino acid (2,824.7 mg/100g),followed by Glu, Leu, Asp, Val, Phe, Ile, Ala and Thr. E/T ratio of protein in pollen load was 2.03 ; protein score, 65.2(Lys) : A/E ratio(egg), 61.7(Lys) : amino acid score, 51.7% after 1hr and on non-fibrous carbohydrate was 80.6%. But that of protein was 67.3% after 1hr, 75.5% after 2hr.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.133-147
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• 2004

Environmental quality(water and sediment) was analyzed in the tidal flat of Saemangum of Jeonbuk Province, the west coast of Korea, using the 101 sediment samples and 69 water samples collected in September 4~13, 2001. Major water quality parameters with the means of 69 surface water samples are as follows; $25.51{\pm}0.68^{\circ}C$ for water temperature, $29.88{\pm}5.01$ for salinity, $1.40{\pm}0.78mg/L$ for COD, $0.352{\pm}0.417mg/L$ for DIN, and $0.027{\pm}0.023mg/L$ for phosphate, respectively. Higher values were found at the subestuary of Dongjin and Mangyung River, and lower values at the Saemangum embayment and Gomso Bay. There was a significant negative correlation between salinity and the other water quality parameters(p<0.0001) such as COD, nutrients, SS and N/P. This correlation suggested that the major pollution sources be from terrestrial inputs through tributaries in this area. Principal component analysis clearly revealed a spatial variation of water quality; stations with higher values of nutrients and COD located subestuary of tributaries. 14 sediment quality parameters including 8 trace metals were measured using the 101 surface sediment samples. Average values for the parameters are as follows; Al $2.28{\pm}0.92%$, Cd $0.61{\pm}0.27ppm$, Cu $8.95{\pm}4.06ppm$, Fe $1.19{\pm}0.37%$, Mn $182.31{\pm}77.45ppm$, Ni $10.83{\pm}4.97ppm$, Pb $15.20{\pm}4.35ppm$, Zn $41.34{\pm}34.62ppm$, COD $2.68{\pm}1.85mg/g\;dry$, AVS $0.04{\pm}0.08mg/g\;dry$, IL $1.29{\pm}1.08%$, water content $24.11{\pm}4.49%$, TN $0.02{\pm}0.02%$, TC $0.22{\pm}0.30%$. Spatial variations of sediment quality were not clear as water quality. Some higher values were found at the subestuary of Gum River and lower values at the other area. There was a significant positive correlation between the heavy metal concentrations and organic materials within the sediment(p<0.05). Enrichment factors showed the ranges of 1~2 for most of the metals in the sediment except zinc(1~6), indicating no serious exogenous input of heavy metals in the study area. Also, the heavy metal concentrations in the sediment were within the ranges found at the natural marine environments.

• Journal of Preventive Medicine and Public Health
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• v.26 no.1 s.41
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• pp.110-125
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• 1993

This study was designed to determine whether non-violent criminal and normal control on the basis of concentration of levels of trace mineral and toxic metal by analysis of human scalp hair. The subjects were selected 87 nonviolent criminal from a prison population and 120 normal control from periodic health checks for study. Hair samples were taken from the napes and Minnesota Multiple Personality Inventory (MMPI) was performed also. Five trace mineral (Zn, Cu, Mg, Fe, Na) and two toxic metal (lead, cadmium) contents were determined by an atomic absorption spectrometer. The contents of zinc and magnesium in hair of non-violent criminal were significantly lower than the control group (p<0.01). In the case of lead and cadimum, mean value of criminal group was significantly higher than control group. Significantly higher T-score of MMPI was seen in non-violent criminal group fur psychopathic deviate (Pd), paranoia scale (Pa), and Mania scale (Ma) than control group, but T-score of depression scale (D) was significantly higher in the control group. In the non-violent criminal group, the content of copper inversely proportion to T-score of Hs, D, Hy, Pd, Mf, Pa, Pt, Sc, Si except Ma, also Zinc inversely proportion to T-score of Hy, Mf, Pa, Pt. These results suggest that difference of some hair mineral contents exist between criminal and normal control group. Thus further studies are necessary to determine whether violent and nonviolent criminal group attributed biochemical imbalance with carefully constructed and controlled studies.

• Journal of Preventive Medicine and Public Health
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• v.27 no.1 s.45
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• pp.25-43
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• 1994

To estimate the factors to the inclination of the criminal violence, the content of trace minerals and toxic metals in the scalp hair were measured during the period from May 1992 to October 1992. One hundred eleven violent and 89 nonviolent criminal inmates of Taegu Correctional Institute were selected. The inmates of violent criminals were imprisoned by murder, robber, rape, injury and violent acts. Those of nonviolent criminals were swindle, larceny, and adultery and had no history of institutional violence. The contents of two toxic metals (cadmium, lead) and five trace minerals (Cu, Fe, Zn, Mg, Na) were determined by an atomic absorption spectrophotometer (IL. 551). The contents of cadmium and lead in hair of violent criminals were significantly higher as $0.56{\pm}0.14ppm,\;11.53{\pm}3.32ppm$, respectively, than $0.42{\pm}0.20ppm,\;9.63{\pm}4.31ppm$ of nonviolent group (p<0.01). But the level of copper was significantly lower than nonviolent group (p<0.05). The factors that had a significant correlation with the inclination of violence in multiple logistic regression analysis were cadmium (odds ratio=98.09), unmarried (odds ratio=0.39), many times of criminal history(odds ratio=1.57) and residence of rural area (odds ratio=0.44). The results suggest that the sub-toxic contents of cadmium and lead in the hair may be of potential effect on behavior, and the mineral analysis may be an important adjunctive diagnostic procedure. Further studies into this problem are necessary.

• Journal of Life Science
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• v.20 no.11
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• pp.1625-1633
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• 2010

This study was carried out to investigate the physicochemical compositions and antioxidative effects of Eriobotrya japonoca Lindl (Loquat). The proximate compositions of the loquat leaf on a dry matter basis were 8.78% moisture content, 6.74% crude protein, 7.87% crude fat, 6.99% crude ash, 43.61% dietary fiber and 26.01% carbohydrate. In analysis of free amino acids, 16 kinds total amino acid components, 17 kinds of components were isolated from loquat. The essential amino acids contained in loquat leaf accounted for 50.15% of total amino acids, while the non-essential amino acids accounted for 49.85%. In analysis of total fatty acids, only 5 kinds of acid were detected: lauric acid, myristic acid, pentadecanoic acid, stearic acid and oleic acid. The contents of vitamin A, vitamin E and vitamin C were 0.039 mg%, 0.096 mg% and 0.575 mg%, respectively. The mineral contents of loquat leaf were greater in order of Zn

• Food Science and Preservation
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• v.8 no.4
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• pp.419-426
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• 2001

This study was carried out to develope a convenient instant spiced Toha-jeot. Toha-jeot was manufactured by five samples; 8%, 10%, 13% 23% sodium chloride and a conventional type soy sauce. The Toha-jeot was refrigerated at 4$\pm$1$\^{C}$ for 3 months and then boiled glutinous rice, red pepper powder, chopped garlic and ginger were added, and the spiced Toha-jeot was fermented at 4$\pm$1$\^{C}$ for 2 months, was freeze-dried at a condition of 40$\^{C}$, vacuum 100∼200 millitor millitorr and then packed in vacuum. It is called freeze-dried instant spiced Toha-jeot (FIST). Changes in the components and quality of refrigerated spiced Toha-jeot (RST) and FIST were investigated for 30day. The moisture content of RST was 53.79∼58.91%. Among the mineral constituents of RST, Na and Ca were dominantly occupying. Water activity of FIST was 0.28-0.39 while that of RST was 0.87-0.92. TBA value of FIST was lower than that of RST. Acidity, VBN (volatile basic nitrogen) and TBA(thiobarbituric acid) of the FIST and RST increased slightly, whereas pH decreased. The major components of fatty acids in FIST and RST were analysed into a feater amount of linoleic acid (Cl8:2), palmitic acid (Cl6:1), oleic acid (Cl8:1), linolenic acid (Cl8:3), EPA (C2O:5) and stearic acid(Cl8:0). In sensory evaluation, the RST had higher scores in color and taste and the FIST in chewiness and flavor. The qualitative characteristics and sensory evaluation of FIST and RST were similar.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.4
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• pp.497-505
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• 2012

The nutritional, physicochemical and sensory quality characteristics of chilled loins of Jeju Black Cattle, Hanwoo and imported Australian beef were compared. For nutritional properties, moisture and crude protein contents of Jeju Black Cattle beef were 65.91% and 17.39% respectively, the lowest among the comparison groups. On the other hand, their crude fat and crude ash contents were 15.89% and 0.79%, respectively, the highest among the comparison groups. There was a significant difference in crude ash content, but there was no significant difference in the other properties. The Fe and Zn contents of Jeju Black Cattle beef were 29.85 and 48.13 ppm, respectively, lower than those of Hanwoo beef, although the difference was not significant. These values were higher than those of Australian beef (p<0.05). There was no significant difference among the samples in contents of Ca, P, Na and Cu. The total amino acid and essential amino acid contents of Jeju Black Cattle beef were 16.81% and 9.08%, respectively, the lowest among the samples, although the difference was not significant. The ratio of essential amino acids to total amino acids of Jeju Black Cattle beef was 54.01%, the highest among the samples. The saturated fatty acid (43.25%), stearic acid (13.51%), linoleic acid (2.39%) and essential fatty acid (2.47%) contents of Jeju Black Cattle beef were the lowest. However, their unsaturated fatty acid (56.69%), oleic acid (47.80%) and MUFA/SFA ratios were the highest, and there were significant differences compared with Australian beef. There was no significant difference in the PUFA/SFA ratio. Among physicochemical properties, redness ($a^*$) of Jeju Black Cattle beef was the highest while melting point was the lowest (p<0.05). There were no significant differences in lightness ($L^*$), yellowness ($b^*$), pH, water holding capacity, cooking loss or shear force value. For sensory properties, raw meat aroma, cooked meat aroma and palatability of Jeju Black Cattle beef were superior compared to other comparison groups, with significant differences in comparison with Australian beef (p<0.05). However, there were no significant differences in taste, juiciness, or tenderness of cooked meat.

• Korean journal of food and cookery science
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• v.24 no.1
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• pp.68-75
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• 2008

The aim of this study was to evaluate the quality characteristics and antioxidant activity of yogurt containing spirulina. Yogurt base was prepared from skim milk added with $0.25{\sim}1%(w/v)$ spirulina powder and fermented with lactic acid bacteria (S. thermophilus : L. bulgaricus = 1 : 1) at $40^{\circ}C$ for 12 hr. Kiwi puree and oligosaccharides were then added. The addition of 1% spirulina powder stimulated the growth of lactic acid bacteria, which showed the highest viable cell count ($3.4{\times}10^9$ CFU/mL), and increased the titratable acidity (1.10%). The viscosity range of the yogurt was 6,000 to 9,000 cP, and the sugar content of the yogurt was around 18 $^{\circ}Brix$. The antioxidant activities were determined using the DPPH method, and the hydroxyl radical scavenging activity of the yogurt containing spirulina was higher than that of the control. The sensory evaluation scores for appearance, odor, taste, overall acceptability and buying intention were higher in the yogurt containing 0.25% spirulina than in the other groups. The amount of macronutrients in the yogurt containing spirulina was higher than that in the control. In addition, the amounts of micronutrients in the yogurt containing spirulina was significantly increased. According to these results, the optimum concentration of spirulina powder is around 0.25%.

• The Journal of Korean Academy of Prosthodontics
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• v.19 no.1
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• pp.17-27
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• 1981

This study was conducted to determine the chemical composition and the mechanical properties of four commercially available low gold-based crown and bridge alloy produced in Korea. Four dental casting gold-silver-palladium alloys, i.e., A, B, C and D (code of alloys) were selected for the evaluation of chemical composition, ultimate tensile strength, elongation. values and Vickers hardness. The chemical composition of test specimens was analyzed by both emission spectrography and wet gravitation method with a 1.5gm of low gold ingot. The tensile properties and Vickers hardness was determined with cast specimens treated in following three conditions; as-cast, softening heat treatment and hardening heat treatment. The tensile testing bars were cast in accordance with the model designed by Gettleman and Harrison (1969) which was modified from the A. D. A. Specification No. 14 for dental chromium-cobalt casting alloy. Nine tensile test specimens were made from a split silicone mold for each of the test alloys to the size of 2.5mm in diameter and a gauge length of 10mm. All four alloys were handled in accordance with conventional methods used in Type III gold alloys. Ultimate tensile strength and elongation were measured on an Instron Universal Tensile Testing Machine (Model 1125, Japan) operated at a crosshead rate of 0.1cm/min. Elongation values were measured using Digital Measuring Microscope (MS-152, FUSOH, Japan). Vickers hardness was determined with a Vickers Hardness Tester (Model VKH-l, Japan) at a 1.0kg load on a mounted tensile test specimen. The following results were obtained from this study; 1. All tested alloys were composed of Au, Ag, Pd, Cu, Zn and Fe in common. The composition rate of gold for all four alloys was found in the range of $42{\sim}47$ weight % as shown below. Alloy A; Au 45%, Ag 40.2%, Pd 5.76%, others 9.04%. Alloy B; Au 47.1%, Ag 29.03%, Pd 6.98%, others 16.92%. Alloy C; Au 45%, .Ag 26.9%, Pd 6.83%, others 21.07%. Alloy D; Au 41.8%, Ag 34.4%, Pd 6.95%, others 16.85%. 3. The ultimate tensile strength of the four alloys was in the range of $31{\sim}82kg/mm^2$. The test results were shown in the below order from the highest value; As-cast condition; D, B, C, A. Softening heat treament; B, C, D, A. Hardening heat treatment; D, B, C, A. 4. The test :results of the elongation rate for each alloy were in the range of $0.5{\sim}18%$. The test results were shown in the below order from the highest value; As-cast condition; A, D, B, C. Softening heat treatment; A, C, D, B. Hardening heat treatment; C, D, B, A. 5. Vickers hardness for each of the four alloys was in the range of $120{\sim}230$. The test results were shown in the below order from the highest value; As-cast condition; C, B, D, A Softening heat treatment; D, B, C, A. Hardening heat treatment; D, A, C, B. 6. There were no differences in the physical properties between as-cast condition and softening heat treatment.