• Journal of fish pathology
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• v.10 no.2
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• pp.165-176
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• 1997

Water samples collected from marine fish culture system in Korea were compared for their capability to reduce the infectivity titers of HRV (rhabdovirus olivaceus), FBV(flounder birnavirus) and RVS(retrovirus of salmonid). In addition, interaction between viruses and microorganisms present in the rearing seawater was examined. The titer of HRV and RVS were reduced at $15^{\circ}C$ to less than detectable limits within 3 to 5 days using untreated samples of seawater. No reduction of infectivity was noted in bacteria-free water treated by filtration or autoclaving. Bacteria (Pseudomonas and Vibrio sp.) isolated from the water collected from a flounder culture system showed the inactivation activity of HRV.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.112-118
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• 1988

The effect of gamma irradiation of microbiological and physicochemical properties of raw ingredients (thirteen kinds of protein sources) for the mixed feed were investigated. The total aerobic bacteria counts in the samples was ranged from $10^2$ to $10^7$cells/g. After 5 to 7 kGy irradiation, the total count was reduced by 3 to 4 log cycles. Coliforms were detected in seven samples and the range was from $10^4$ to $10^6$cells/g. Enteric pathogens were found only in fish meal and poultry byproduct as $10^2$ to $10^6$cells/g. They were sensitive to radiation and completely sterilized by 3 to 5 kGy irradiation. Total fungi count was ranged from $10^1$ to $10^4$cells/g in all samples. They were osmophiles such as Aspergillus, Penicillium, Cladosporium, Aureobasidium and Rhizopus and were destroyed by 3 to 7 kGy irradiation. Five species of potential mycotoxin producers including Aspergillus flavus were also identified. Physicochemical properties, such as total amino acid content, TBA value, POV and color difference showed that irradiation with optimum does was less detrimental than autoclaving.

• Journal of Chest Surgery
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• v.17 no.1
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• pp.157-166
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• 1984

These biologic test procedures are designed to test the suitability of P.V.C. made in Korea intended for parenteral preparation, which were based on the U.S. Pharmacopeia XIX "Biologic Test-Plastic Container", Official from July 1, 1975. Healthy adult human blood and rabbits weighing 2\ulcorner.2Kg were used for test materials. Sample P.V.C. were sampled from the medical equipments made in Korea randomly and Control P.V.C. were sampled from the standardized Cobe and Polystan P.V.C. tubes. P.V.C. extract was prepared from a homogeneous P.V.C. samples by incubating 60 square centimeters of the sample per 20 millimeters of sterile pyrogen-free saline at 70\ulcorner for 72 hours or autoclaving at 120\ulcorner for 1 hour. The Implantation Test was designed to evaluate the reaction of living tissue to the plastic by the method of the implantation of the Sample itself into animal tissue. The Systemic Injection Test, the Intracutaneous Test, and the remainders were designed to determine the biological response of animals to plastics by the single-dose injection of specific extracts prepared from a Sample. The results are as follows; 1.Implantation Test - No significant difference for reactions was noted between the Sample treated animal and the Control after 72 hours of implantation. 2.Systemic Toxicity Injection Test - No sign of toxicity and/or death immediately after injection and at 4, 24, 48 hours respectfully after injection. 3.Intracutaneous Test - None of the animals treated with the Sample showed a significantly greater reaction than the observed in the animals treated with Blank. 4.Pyrogen Assay-Only one animal treated with the Sample showed the maximal rise of rectal temperature about 0.2\ulcorner after 3 hours of injection, but remainders showed no change. 5.Hemolytic Index - The positive Control tube of distilled water exhibited complete hemolysis while the negative Control tube and P.V.C. extract were negative demonstrating no hemolysis. 6.Cell Morphology of Erythrocytes and Leukocytes on Stored, Heparinized Human Blood -- There was no significant difference in the morphology of either the Control or Sample extract. 7.Clotting Mechanism of Human Blood in vitro - After allowing to the P.V.C. extract at room temperature for 5 Hours and at 10\ulcorner for 24 hours, there was no appreciable difference in Prothrombin Time under these conditions. 8.Clotting Mechanism of Rabbit in vivo - At the termination of 5 days after intraperitoneal injection of the P.V.C. extract, no significant changes in Clotting Time were observed. According to the above results, it could be concluded that the P.V.C. made in Korea was acceptable for parenteral preparation, especially treated with physiologic saline and/or human blood.man blood.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.18-26
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• 1996

We investigated the effect of deep-freezed, boiled and autoclaved autogenous long bone graft on the incorporation of the radial diaphyseal reconstruction in 30 rabbits by radiogram and histology for 8 weeks. Immediate histologic changes of 1cm of resected long bone treated by deep freezing, boiling and autoclaving in each 2 rabbits were also observed as control. Resected, boiled ($95^{\circ}C$ for 5 min.) and reimplanted bone was compared with resected, autoclaved ($131^{\circ}C$ for 5 min.) and reimplanted bone, and resected, deep freezed with liquid nitrogen for 5 minutes and thawing in saline and reimplanted bone in the reconstruction of bilateral radial defects in each of 8, and in total 24 adult rabbits. The results were as follows : 1. Immediate histologic changes showed that intracortical osteocytes in lacunae were partially necrotized and the cortex were faintly stained with they Masson trichrome stain in both boiled and deep freezed groups, while they completely necrotized and their cortex stained more weakly with Masson trichrome stain in autoclaved group which means less amount of collagen and protein in cortex of long bone. 2. Radiographies at 8 weeks showed complete union with more marked incorporation and external callus formation in all boiled and freezed groups, whereas there was delayed union in four of sixteen (25%) in autoclaved group. Histologically, at 8 weeks after boiled and freezed, more intense incorporation with new bone formation and neovascularization were observed, whereas transverse clefts consisted with delayed union in 4 cases of autoclaved group (25%) were observed at osteotomy site. Through these studies, the boilod and deeply freezed bones acted as an osteoinductive material as well as osteoconductive, but the autoclaved bone only as osteoconductive. Though boilod and deeply freezed bone showed higher osteogenic potentials than autoclaved bone, the necrotizing effect on cortical and boiled bone was inferior to that of autoclaved. Thus the deeply freezed bone can be used for the treatment of aggressive benign or less malignant bone tumor not involving cortical bone, but the autoclaved bone supplemented with bone graft for the treatment of malignant bone tumor involving cortex of long bone.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.543-548
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• 2008

Solid hydrated by hydro-thermal synthesis reaction is cured two times, the first curing is the steam curing at atmospheric pressure and the second one is a high-pressure steam curing, that is autoclaving. Steam curing is to acquire the proper strength for the resistance of treatment in the first curing process, it was not evaluated properly so far. Because of ignorance about curing, some engineers even think that the dry curing is better than the steam curing. The relation between compressive strength of solid hydrated by hydrothermal synthesis reaction and curing condition are presented in this paper. In order to investigate the effect of curing on the strength properties of specimen, the hydration behavior of solid hydrated by hydro-thermal synthesis reaction has been studied over curing condition using XRD, DT-TGA and porosimeter, SEM analysis technique. The results show that the specimens which are cured with blended method of dry and steam curing appear to have better strength properties than that of dry curing and steam curing. Also, there are significant difference of hydration behavior among curing condition in the solid hydrated by hydro-thermal synthesis reaction.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.212-217
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• 2002

We purified polyphenols from persimmon leaf and tested their biological activity. The 60% acetone extract was lyophilized and applied to test enzyme inhibition of glucosyltransferase and tyrosinase. GTase was 82.4% inhibited at $1.8{\times}10^{-1}$ mg/ml and tyrosinase 21.7% inhibited at 0.8 mg/ml. The acetone extract was fractionated into F-1, 2, 3, 4, 5 by Sephadex Q-50 gel filtration and the fraction-1 and 2 showed higher enzyme inhibition activity than the other fractions. To the Proteinase K treatment and autoclaving of the two fractions had no effect on the enzyme activity, but these results suggested that active fraction was not protein but phenol ring completed compounds. By Sephadex LH-20, MCI-gel and Bondapak $C_{18}$ column chromatographies, compouds 1, 2, 3 and 4 from F-1 fraction, compounds 5 and 6 from F-2 fraction and compounds 7 , 8 from F-3 fraction were purified and re-crystallized. The purified compounds was assumed to be condensed tannins of frame flavan-3-ol frame on the basis of color reagent reaction and to be a mixture of monomer, dimer and trimer according to TLC analysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.158-163
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• 2000

As a part of investigation for utilizing of canned tuna processing by-products as a food resource, we examined the processing conditions and characteristics (extraction methods and ashing condition) of a calcium powder from skipjack tuna bone. Among ashing, autoclaving, and shaking methods for extraction of calcium powder from skipjack tuna bone, ashing method was superior to other methods on the aspect of fish odor, white index, and calcium recovery of calcium powder. Based on the results of white index and soluble calcium ratio, the optimal ashing temperature and time for preparation of a calcium powder from skipjack tuna bone was at $900{\circ}C for 15 min$. Cohesive ratio of calcium powder by shaking at pH 7.0 was increased up to 16 hrs, but after that almost unchanged. Cohesive ratio of calcium powder by shaking for 24 hrs was increased at neutral and alkaline conditions (pH 6-8 and pH 9-11), but almost unchanged at acidic conditions (pH 2-5). For the effective utilization of the calcium powder from skipjack tuna bone, a suitable treatment is needed for improvement of calcium solubility at neutral condition.

• Journal of the Korean Professional Engineers Association
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• v.34 no.2
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• pp.167-173
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• 2001

Through alkaline hydrothermal activation processes, Na-A type zeolite was synthesized as a single phase withfunnel-glass waste from a television tube factory. The autoclaving was performed in a closed teflon vessel in therange of 80~95"C. The silica-rich solution as a starting material was hydrothermally synthesized with quartz in INNaOH by heating 350"C under the pressure of 1,500 atm. NaA102 was made from NaOH and Al(OH)3 by heating95"c for 2~3 hours and the molar ratios of it were Na20/A1203=1.4 and H20Ha20=8. The equi-dimensional Atype zeolite (1 ~2 U) was formed by the simple mixing of'the silica-rich solution, glass waste and NaA102 for I~3hours-heating at 80"C. The characterization of the reaction product shows Na-A as a single phase. The synthesizedzeolite has cube-dodecahedral form and Ca2+ ion exchange capacity of the Na-A was in the range of 215~220mequivalent/100 g.20mequivalent/100 g.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.107-114
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• 2007

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms' activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

• The Journal of Advanced Prosthodontics
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• v.1 no.3
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• pp.113-117
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• 2009

STATEMENT OF PROBLEM. Recently Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) has been introduced due to superior flexural strength and fracture toughness compared to other dental ceramic systems. Although zirconia has outstanding mechanical properties, the phenomenon of decrease in the life-time of zirconia resulted from degradation in flexural strength after low temperature aging has been reported. PURPOSE. The objective of this study was to investigate degradation of flexural strength of Y-TZP ceramics after various low temperature aging treatments and to evaluate the phase stability and micro-structural change after aging by using X-ray diffraction analysis and a scanning electron microscope (SEM). MATERIAL AND METHODS. Y-TZP blocks of Vita In-Ceram YZ (Vita Zahnfabrik, Bad $S\ddot{a}ckingen$, Germany) were prepared in 40 mm (length) $\times$ 4 mm (width) $\times$ 3 mm (height) samples. Specimens were artificially aged in distilled water by heat-treatment at a temperature of 75, 100, 125, 150, 175, 200, and $225^{\circ}C$ for 10 hours, in order to induce the phase transformation at the surface. To measure the mechanical property, the specimens were subjected to a four-point bending test using a universal testing machine (Instron model 3365; Instron, Canton, Mass, USA). In addition, X-ray diffraction analysis (DMAX 2500; Rigaku, Tokyo, Japan) and SEM (Hitachi s4700; Jeol Ltd, Tokyo, Japan) were performed to estimate the phase transformation. The statistical analysis was done using SAS 9.1.3 (SAS institute, USA). The flexural strength data of the experimental groups were analyzed by one-way analysis of variance and to detect statistically significant differences ($\alpha$= .05). RESULTS. The mean flexural strength of sintered Vita In-Ceram YZ without autoclaving was 798 MPa. When applied aging temperature at below $125^{\circ}C$ for 10 hours, the flexural strength of Vita In-Ceram YZ increased up to 1,161 MPa. However, at above $150^{\circ}C$, the flexural strength started to decrease. Although low temperature aging caused the tetragonal-to-monoclinic phase transformation related to temperature, the minimum flexural strength was above 700 MPa. CONCLUSION. The monoclinic phase started to appear after aging treatment above $100^{\circ}C$. With the higher aging temperature, the fraction of monoclinic phase increased. The ratio of monoclinic/tetragonal + monoclinic phase reached a plateau value, circa 75% above $175^{\circ}C$. The point of monoclinic concentration at which the flexural strength begins to decrease was between 12% and 54%.