• Journal of Oral Medicine and Pain
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• v.33 no.3
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• pp.229-240
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• 2008

Animal mucins have structural characteristics similar to human salivary mucins. Animal mucins have been regarded as suitable substances for saliva substitutes. Since animal mucin molecules in saliva substitutes and host-derived antimicrobial salivary molecules exist simultaneously in whole saliva and the pellicles of patients with dry mouth, interactions may occur between these molecules. The purpose of this study was to investigate the influence of animal mucins on peroxidase activity in solution and on the surface of hydroxyapatite(HA) surfaces. The effects of animal mucins on peroxidase activity were examined by incubating porcine gastric mucin(PGM) or bovine submaxillary mucin (BSM) with either bovine lactoperoxidase(bLPO) or saliva samples. For solid-phase assays, immobilized animal mucins or peroxidase on three different HA surfaces(HA beads, HA disc, and bovine tooth) were used. Peroxidase activity was determined with an NbsSCN assay. The obtained results were as follows: 1. PGM enhanced the enzymatic activity of bLPO in solution phase. PGM did not affect the enzymatic activity of peroxidase in saliva sample(POS). 2. BSM did not affect the enzymatic activities of both bLPO and POS in solution phase. 3. HA-adsorbed PGM increased subsequent bLPO adsorption in all three HA phases. The activity of POS was increased on both the HA beads and bovine tooth. 4. The peroxidase activities on the HA beads and disc were increased when the HA surfaces were exposed to a mixture of bLPO and PGM. 5. The binding affinity of bLPO to PGM was greater than that of bLPO to BSM. Collectively, our results suggest that animal mucins affects the enzymatic activity of peroxidase on the HA surfaces as well as in solution. Saliva substitutes containing animal mucins may affect the function of antimicrobial components in natural saliva and saliva substitutes.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.1
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• pp.9-17
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• 2010

The LCC (Liquid Cadmium Cathode) structure to be developed for inhibiting the formation and growth of the uranium dendrite has been known as a key part in the electrowinning process for the simultaneous recovering of uranium and TRU (TRans Uranium) elements from spent fuels. A zinc-gallium (Zn-Ga) experimental system which is able to be functional in aqueous condition and normal temperature has been set up to observe the formation and growth phenomena of the metal dendrites on liquid cathode. The growth of the zinc dendrites on the gallium cathode and the performance of the existing stirrer type and pounder type cathode structure were observed. Although the mechanical strength of the dendrites appeared to be weak in the electrolyte and easily crashed by the various cathode structures, it was difficult to effectively submerge the dendrite into the bottom of the liquid cathode. Based on the results of the aqueous phase experiments, a lab-scale electrowinning experimental apparatus which are applicable to the development of LCC srtucture for the electrowinning process was established and the performance tests of the different types of LCC structure were conducted to prohibit the uranium dendrite growth on LCC surface. The experimental results of the stirrer type LCC structures have shown that they could not effectively remove the uranium dendrites growing at the inner side of the LCC crucible and the performances of the paddle and harrow type LCC structure were similar. Therefore a mesh type LCC structure was developed to push down the uranium dendrites to the bottom of the LCC crucible growing on the LCC surface and at the inner side of the crucible. From the experimental results for the performance test of the mesh type LCC structure, the uranium was recovered over 5 wt% in cadmium without the growth of uranium dendrites. After completion of the experiments, solid precipitates of the bottom of the LCC crucible were identified as an intermetallic compound (UCd11) by the chemical analysis.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.206-214
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• 2005

Heterogeneously-catalyzed oxidation of aqueous phase trichloroethylene (TCE) over supported metal oxides has been conducted to establish an approach to eliminate ppm levels of organic compounds in water. A continuous flow reactor system was designed to effect predominant reaction parameters in determining catalytic activity of the catalysts for wet TCE decomposition as a model reaction. 5 wt.% $CoO_x/TiO_2$ catalyst exhibited a transient period in activity vs. on-stream time behavior, suggesting that the surface structure of the $CoO_x$ might be altered with on-stream hours; regardless, it is probable to be the most promising catalyst. Not only could the bare support be inactive for the wet decomposition reaction at $36^{\circ}C$, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Very low TCE conversion appeared for $TiO_2$-supported $NiO_x$ and $CrO_x$ catalysts. Wet oxidation performance of supported Cu and Fe catalysts, obtained through an incipient wetness and ion exchange technique, was dependent primarily on the kinds of the metal oxides, in addition to the acidic solid supports and the preparation routes. 5 wt.% $FeO_x/TiO_2$ catalyst gave no activity in the oxidation reaction at $36^{\circ}C$, while 1.2 wt.% Fe-MFI was active for the wet decomposition depending on time on-stream. The noticeable difference in activity of the both catalysts suggests that the Fe oxidation states involved to catalytic redox cycle during the course of reaction play a significant role in catalyzing the wet decomposition as well as in maintaining the time on-stream activity. Based on the results of different $CoO_x$ loadings and reaction temperatures for the decomposition reaction at $36^{\circ}C$ with $CoO_x/TiO_2$, the catalyst possessed an optimal $CoO_x$ amount at which higher reaction temperatures facilitated the catalytic TCE conversion. Small amounts of the active ingredient could be dissolved by acidic leaching but such a process gave no appreciable activity loss of the $CoO_x$ catalyst.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.4
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• pp.316-323
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• 2011

Purpose: The purpose of this study was to investigate the effect of different thread designs on the marginal bone stresses around dental implant. Materials and methods: Standard ITI implant(ITI Dental Implant System; Straumann AG, Waldenburg, Switzerland), 4.1 mm in diameter and 10 mm in length, was selected as control. Test implants of four different thread patterns were created based on control implant, i.e. maintaining all geometrical design of control implant except thread pattern. Four thread designs used in test implants include (1) small V-shape screw (model A), (2) large V-shape screw (model B), (3) buttress screw (model C), and (4) trapezoid screw (model D). Surface area for unit length of implant was 14.4 $mm^2$ (control), 21.7 (small V-shape screw), 20.6 (large V-shape screw), 17.0 (buttress screw) and 28.7 $mm^2$ (trapezoid screw). Finite element models of implant/bone complex were created using an axisymmetric scheme with the use of NISA II/DISPLAY III (Engineering Mechanics Research Corporation, Troy, MI, USA). A load of 100 N applied to the central node on the crown top either in parallel direction or at 30 degree to the implant axis (in order to apply non-axial load to the implant NKTP type 34 element was employed). Quantification and comparison of the peak stress in the marginal bone of each implant model was made using a series of regression analyses based on the stress data calculated at the 5 reference points which were set at 0.2, 0.4, 0.6, 0.8 and 1.0 mm from implant wall on the marginal bone surface. Results: Results showed that although severe stress concentration on the marginal bone cannot be avoided a substantial reduction in the peak stress is achievable using different thread design. The peak marginal bone stresses under vertical loading condition were 7.84, 6.45, 5.96, 6.85, 5.39 MPa for control and model A, B, C and D, respectively. And 29.18, 26.45, 25.12, 27.37, 23.58 MPa when subject to inclined loading. Conclusion: It was concluded that the thread design is an important influential factor to the marginal bone stresses.

• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.7-17
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• 1985

Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.

• Applied Microscopy
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• v.30 no.4
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• pp.357-365
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• 2000

Paneth cells have been suggested to contribute to the elimination of excess metals into the intestinal lumen. The purpose of this study wat to investigate the changes of the zinc pools in rats subjected to functional loading with zinc salt by mean of both light and electron microscopical autometallography (AMG). Wistar rats 4 were administrated with zinc chloride (20 mg/kg body weight) intraperitoneally dissolved in 1 ml distilled water. The control group received 1 ml saline IP. After further one hour the animals were transcardially perfused with 0.4% sodium sulphide dissolved in 0.1 M PB fellowed by 3% glutaraldehyde solution for 10 minutes. Pieces of ileum were frozen with solid $CO_2$ and sectioned on a cryostat. The sections $(20{\mu}m)$ were autometallographically developed. Sections selected for EM were reembedded on top of a blank Epon block, from which ultrathin sections (100 nm) were cut. The ultrathin sections were double stained with uranyl acetate (30 min) and lead citrate (5 min), then examined under electron microscope. Studies of comparable sections from control and zinc loaded animals with the AMG selenium method gave quite different results. The control animals demonstrated a weakly positive staining in the cytoplasm of the Paneth cells. In the electron microscope the AMG silver grains were found to be located in the cytoplasm, while the electron dense secretary granules and other cell organelles were void of staining. Few AMG grains were located at the apical surface of the Paneth cells. In sections from zinc loaded rats, the AMG grains were seen in abundance in the lumen of the Lieberkuhn crypts at light microscopic levels. At EM levels the zinc revealing silver grains were located in the cytoplasm as in the controls, but much more AMG grains were shifted into the secretary granules. Furthermore, profound AMG grains were found in the lumen of the crypts and surrounding vessels. And a few grains were seen in the endothelium. The AMG technique demonstrated a pattern of AMG grains in the Paneth cells that strongly suggests a transport of zinc ions through these cells.

• Korean journal of food and cookery science
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• v.26 no.1
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• pp.62-71
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• 2010

The followings describes the result of making doenjang with added licorice (Glycyrrhiza uralensis) powder. and investigating its sensory characteristics and physicochemical quality. General preference was high at 20% salinity and 2% licorice (LD204), and 16% salinity and 2% licorice (LD162). The moisture content was unchanged in the control group, while it was reduced in LD204 and LD162 in the first week of fermentation, but showed little change after then. pHs were all in the range 5.90~5.97 on day 0, but decreased from 5.90 to 5.72 in the control group in the fifth week. LD204 changed from 5.95 on day 0to 5.42 in the first week, and then it gradually increased again and became 5.93 in the fifth week, which was similar to that of day 0. LD162 was 5.97 on day 0 and showed cyclic slight increases and decreases in the first week. It increased to 6.32 in the fifth week, which was higher than that of day 0 that is, its pH was higher than that of LD204. The acidity showed a difference right after it was made. In the control group, lactic acid content gradually increased from 0.16% on day 0 to the highest, 0.59%, in the fourth week. It slightly decreased in the fifth week. LD204 slowly increased from 0.25% on day 0 to a maximum, 0.50%, in the fourth week. It also slightly decreased in the fifth week, quite similarly to that of the control group. LD162, gradually increased from 0.22% on day 0 to the highest, 0.49, in the third week, and decreased after the fourth week. Salinity was 29.5%, 22.0%, and 18% in each of the control group, LD204, and LD162 on day 0 but increased to 34.0%, 29.0%, and 26.0% in the fifth week. Soluble solid was $32^{\circ}Brix$, $28^{\circ}Brix$, and $26^{\circ}Brix$ in each of the control group, LD204, and LD162 on day 0, but slightly increased to $40^{\circ}Brix$, $32^{\circ}Brix$, and $30^{\circ}Brix$ on the fifth day. It is thought that because of the sweetness of licorice, the higher-salinity doenjang earned a higher sensory test score than that of traditional doenjang. If its salinity is lowered a little, it could be used as a sauce, even possibly having medical effects as well.

• Progress in Medical Physics
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• v.21 no.1
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• pp.86-92
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• 2010

The purpose of this study was to measure curvature contour skin dose using radiochromic film and TLD for a conventional open field. We also attempted to quantify the degradation of skin sparing associated with use of immobilization devices for high energy photon beams and to calculate the skin dose with a help of Monte Carlo (MC) simulation. To simulate head-and-neck and shoulder treatment, a cylindrical solid water phantom 11 cm in diameter was irradiated with 6 MV x-rays using $40{\times}40\;cm^2$ field at 100 cm source axis distance (SAD) to the center of the phantom. Aquaplastic mesh mask was placed on the surface of the cylindrical phantom that mimicked relevant clinical situations. The skin dose profile was obtained by taking measurements from $0^{\circ}$ to $360^{\circ}$ around the circumference of the cylindrical phantom. The skin doses obtained from radiochromic film were found to be 47% of the maximum dose of $D_{max}$ at the $0^{\circ}$ beam entry position and 61% at the $90^{\circ}$ oblique beam position without the mask. Using the mask (1.5 mm), the skin dose received was 59% at $0^{\circ}$ incidence and 78% at $80^{\circ}$ incidence. Skin dose results were also gathered using thin thermoluminescent dosimeters (TLD). With the mask, the skin dose was 66% at $0^{\circ}$ incidence and 80% at $80^{\circ}$ incidence. This method with the mask revealed the similar pattern as film measurement. For the treatments of the head-and-neck and shoulder regions in which immobilization mask was used, skin doses at around tangential angle were nearly the same as the prescription dose. When a sloping skin contour is encountered, skin doses may be abated using thinner and more perforated immoblization devices which should still maintain immoblization.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.278-286
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• 2010

Veterinary antibiotics have been used to treat disease and to promote growth of livestock. However, the total amount of veterinary antibiotics in Korea was much greater than other developed countries, and there is a high potential to release residual of antibiotics to environment. Consequentially, released antibiotics into the environment produces antibiotic resistant bacteria and causes adverse effects on human health. The objective of this research was to monitor antibiotic concentration in the environment adjacent to facilities which compose chicken manure. Total of 10 antibiotics were selected based on the total amount of higher usage in Korea, and its residuals were measured from surface water, soil and sediment. The frequencies of detected antibiotics were ranged 31-92% from soil, 0-93% from water, and 33-93% from sediment. Generally, a higher frequency was observed in soil or sediment than water. Different ranges in concentration among 4 different antibiotic groups was found from not detected(N.D.) to 35.6 ${\mu}g/kg$ for soil, N.D. to 19.2 ${\mu}g/L$ for water and N.D. to 114.3 ${\mu}g/kg$ for sediment. Our findings suggest that solid phase such as soil and sediment is a critical component to be needed to conduct the environmental impact assessment of antibiotics.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.62-71
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• 2014

Three types of diffuser systems were manufactured and applied to investigate the effect of liquid fertilization of pig manure slurry by application of aeration processes. In the first type reactor, commonly used diffuser system, which diffuse air upward by diffusing aerator fixed at the bottom of the reactor is installed. In case of the second type, air diffuser is installed 10 cm above of the bottom of a reactor. In the third type reactor, the venturi-type air diffuser is installed at circulation pipe, which return pig slurry in the reactor(mixing-in-pipe process). The pig manure slurry separated to solid/liquid was flowed into the experimental reactor, and left as it for one week to precipitate solids. The concentration of organic matter, T-N, T-P and BOD in the raw pig manure slurry flowed into the reactor of bottom-fixed type aeration process were 1.82%, 4,400 mg/L, 360 mg/L and 13,542 mg/L, respectively. After aeration the concentration of organic matters, T-N, T-P and BOD in the slurry were 2.01%, 4,400 mg/L, 420 mg/L and 16,824 mg/L, respectively. The concentration of organic matter, T-N, T-P and BOD in the mixing-in-pipe type changed from 1.58%, 3,700 mg/L, 260 mg/L and 15,735 mg/L to 1.96%, 4,000 mg/L, 340 mg/L, and 18,098 mg/L, respectively. Changes of the concentration of organic matter, T-N, T-P and BOD of the pig manure slurry collected from the middle layers of two aeration reactors; bottom aeration process and the mixing-in-pipe process, were 10.4%, 0%, 16.7% and 24.2% and 24.0%, 8.1%, 30.8% and 15.0%, respectively. The thickness of foam layer generated on the surface of pig manure slurry in aeration tank was thinner in mixing-in-pipe reactor than bottom-fixed type aeration reactor.