• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.497-503
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• 2010

Purpose: The purpose of this study is to induce artificial arthritis on rabbit TMJ by injecting collagenase. Materials and Methods: An experimental animal model of arthritis induced by surgical method or intraarticular injection of chemical agent like LDH, papain, ketorolac. Surgical method is complex and needs a long time in inducing arthritis. Intra-articular injection of chemical agent like LDH, papain, ketorolac is simple. But chemical agent like LDH, papain, ketololac needs multiple injections to induce arthritis and mechanism inducing arthritis was known. Collagenase destroys helical domain of type II collagen in extracellular matrix produced by chondrocyte and then induces arthritis. We injected collagenase (0.5, 1.0, 2.0 mg) into the temporomandibular joint of rabbit. In the control group saline was intra-articularly injected. The condylar cartilage, disk and synovia were histologically examined at 1, 2, 4, 6 weeks after the initiation of collagenase injections. Results: Four weeks after injection of 2.0 mg collagenase, we could see histologic change like arthritis. In other groups, we couldn't see arthritis-like change. Conclusion: In our study, we produce arthritis on temporomandibular joint of rabbit by using injection of collagenase in temporomandibular joint of rabbit. And this experimental osteoarthritis is a useful animal model.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.476-485
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• 1992

M1 plants which were produced from seed soaking in chemical mutagen, EMS or NaN$_3$, appeared wide morphorogical variations such as dwarf, albino, twisted leaf, white streaked leaf, and purpled stem. In mutants of reproductive organs, there were monoecious plants such as female-flower plant and male-flower plant, multiple spikes, and steriled plants among M1 plants. Also, barren stalk was increased significantly in M1 plants. Ear bagging at ear initiation stage prevented seed set on cob in normal plants. In spite of ear bagging, M1 plants which had cobs with seed set was 3.9-11.2% of stalks developed from seeds soaking with mutagens, but only three or four kernels could be matured on a cob. Ear bagging after mutagen injection into initiating ear produced 5.1-10% in cobs with seed set, but only 1.7-6.3 kernels could be matured. Cobs removed silk at four hours after artificial pollination increased the rate of cobs with seed set to 27%. Microscopic observation confirmed that ontogeny of kernels matured from ear bagging and mutagen treatment would be both adventitious and diplosporous apomictic reproduction. Chromosome set of M2 seedling was found to be diploid type in chromosomal counting of root tip. As M$_2$ plants showed an uniform appearence within each lines and their CV of plant height were ranged 4-6% in each lines, we concluded that they were apomictic progeny. But we could not find any marker traits combined with apomixis.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.42-46
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• 2004

Deep Ocean Water (DOW) is formed within restricted area including polar sea (high latitude) by cooling of surface seawater and globally circulating in the state of isolation from surface seawater. Although it is not as obvious as estuaries mixing, brine ground water is mixture of recirculated seawater and ground water. Seawater having high osmotic pressure infiltrates into an aquifer which is connected to the sea. In order to clarify the characteristics of deep ocean water and brine ground water, we investigated their origins, chemical compositions, water qualities and resources stabilities. While concentrations of stable isotopes (/sup 18/O and ²H) in seawater is 0‰, those in brine ground water is on meteoric water line or shifted toward oxygen line. It means that origin of brine ground water is different than that of deep ocean water. The ions dissolved in seawater (Na, Ca, Mg, K) are present in constant proportions to each other and to the total salt content of seawater. However deviations in ion proportions have been observed in some brine ground water. Some causes of these exception to the rule of constant proportions are due to many chemical reactions between periphery soil and ground water. While DOW has a large quantity of functional trace metals and biological affinity relative to brine ground water, DOW has relatively small amount of harmful bacteria and artificial pollutants.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.723-730
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• 2011

In this experiment, persulfate, a strong oxidant for ISCO (In-Situ Chemical Oxidation) was used to degraded RDX in artificial ground water at ambient temperature. Results of RDX degradation by persulfate in a batch reactor showed that the oxidation reaction was pseudo first order with estimated Ea (activation energy) of $1.14{\times}10^2kJ/mol$ and the rate was increased with the increase of reaction temperature. The oxidation of RDX by persulfate increased slightly with the increase of initial solution pH from 4 to 8. The RDX oxidation rate increased 13 times at pH 10 compared with that at pH 4, however, alkaline hydrolysis was found to be the main reaction of RDX degradation rather than oxidation. The study also showed that the oxidation rate of RDX by persulfate was linearly dependent upon the molar ratios of persulfate to RDX from 5 : 1 up to 100 : 1, with a proportion constant of $4{\times}10^{-4}$ ($min^{-1}$/molar ratio) at $70^{\circ}C$. While NOM (Natural Organic Matter) exerted negative effects on the oxidation rate of RDX by persulfate, with a proportion constant of $1.21{\times}10^{-4}$ ($min^{-1}{\cdot}L/mg-NOM$) at $70^{\circ}C$ and persulfate/NOM molar ratio of 10/1. The decrease in RDX oxidation rate was linearly dependent upon the added NOM concentration. However, the estimated activation energy in the presence of 20 mg-NOM/L was within 3.3% error compared to that without NOM, which implies the addition of NOM does not alter intrinsic oxidation reaction.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.285-291
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• 2015

Purpose: The hydrogel lenses have been functionalized with HA(Hyaluronic Acid) using two different methods: construction of an IPN(Interpenetrating Polymer Networks) and formation of CCB(Chemical Covalent Bonding). The lysozyme adsorption and physical properties such as optical transmittance and water content of the hydrogel lenses have been investigated in order to determine whether method is suitable for the application potentials in contact lens industry. Methods: HA have been added to the hydrogel lenses prepared in the Lab using the two different method, e.g. IPN and CCB. The optical transmittance was measured in the wavelength range of 300~800 nm. The water content was measured by the gravimetric method using 0.9% NaCl saline solution. The amounts of adsorbed lysozyme on the contact lenses was analyzed by HPLC after incubation for 12h in artificial tears. Results: The water content of the HA added hydrogel contact lenses was increased, and the lens made by IPN method showed higher water content than the lens made by CCB method. The optical transmittance was over 90% both before and after addition of HA. Comparing the lysozyme adsorption reduction ratio, contact lens manufactured by IPN method was 60.0%, and the lens made by CCB method was 40.4%. Conclusions: CCB method is appropriate to distribute the functional material evenly throughout the lens, whereas IPN method is effective for the case of giving the functionality on the lens surface without phase separation.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.301-308
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• 1987

The results of experiment to find out the optimum pasteurization condition by heating from $50^{\circ}C$ to $70^{\circ}C$ at intervals of $5^{\circ}C$ and to review chemical composition, microbiological aspects and keeping quality were summarized as follows: 1. The milk sample pasteurized at $50-70^{\circ}C$ showed the decreased pH value from 6.55 to 6.42 while the contents of protein, fat, lactose and ash did not have significant changes. 2. Non-casein nitrogen and filterable nitrogen decreased while casein nitrogen and non protein nitrogen increased as the heat treatment increased. 3. The content of calcium and vitamin C decreased and artificial digestibility for the pasteruized milk increased from 14.07% to 20.00% by the heat treatment. 4. Milk pasteurized at $65^{\circ}C$ had viable bacteria counts $1.3{\times}10^4/m{\ell}$, coliforms negative, psychrotrophic bacteria $9.5{\times}10^2/m{\ell}$ and 99.0% pasteurization effect. 5. Milk pasteurized at $65^{\circ}C$ did not show significant changes in chemical composition and microbiological aspects at $4^{\circ}C$ in refrigerator.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.562-572
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• 2005

Statement of problem : Titanium is widely used as an implant material lot artificial teeth. Also, studies on surface treatment to form a fine passive film on the surface of commercial titanium or its alloys and improving bioactivity with bone have been carried out. However, there is insufficient data about the biocompatibility of the implant materials in the body. Purpose: The purpose of this study was to examine whether the precipitation of apatite on titanium metal is affected by surface modification. Materials and methods: Specimens chemically washed for 2 minute in a 1:1:1.5 (in vol%) mixture of 48% HF 60% $HNO_3$ and distilled water. Specimens were then chemically treated with a solution containing 97% $H_2SO_4$ and 30% $H_2O_2$ at $40^{\circ}C$S for 1 hour, and subsequently heat-treated at $400^{\circ}C$ for 1 hour. All specimens were immersed in the HBSS with pH 7.4 at $36.5^{\circ}C$ for 15 days, and the surface were examined with TF-XRD, SEM, EDX and XPS. Also, commercial purity Ti specimens with and without surface treatment were implanted in the abdominal connective tissue of mice for 4 weeks. Conventional aluminium and stainless steel 316L were also implanted for comparison. Results and conclusions : The results obtained were summarized as follows. 1. An amorphous titania gel layer was formed on the titanium surface after the titanium specimen was treated with a $H_2SO_4$ and $H_2O_2$ solution. The average roughness was $2.175{\mu}m$ after chemical surface treatment. 2. The amorphous titania was subsequently transformed into anatase by heat treatment at $400^{\circ}C$ for 1 hour. 3. The average thickness of the fibrous capsule surrounding the specimens implanted in the connective tissue was $46.98{\mu}m$ in chemically-treated Ti, and 52.20, 168.65 and $100.95{\mu}m$ respectively in commercial pure Ti, aluminum and stainless steel 316L without any treatment.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.225-231
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• 2006

The objective of this study was to determine changes in serum hormone concentrations, blood chemical values and recovery rate of in vivo embryos during the estrous cycle following super-ovulation treatments in Jeju black cows. Superovulation was induced by subcutaneous administration of FSH twice a day for 4 days. Serum hormones were assayed by radioimmunoassay (RIA) and blood chemical values were analyzed by blood analyser system. Embryos were collected from all treated black cows using nonsurgical technique on day 7 after artificial insemination (AI). The results of this study were summarized as follows: 1. The progesterone concentrations were $7.2{\pm}3.8ng/ml$ at day -11 and $0.3{\pm}0.1ng/mL$ at day 0 (Day 0 is the first day of AI). The estradiol concentrations were $10.6{\pm}4.48pg/ml$ at day -11 and $15.0{\pm}2.2pg/ml$ at day 0. The lowest level of progesterone was measured at day 0. The highest levels of estradiol was measured at day 0. 2. The blood chemical values of treated black cows were no significant differences in normal cow values. 3. Sixty two embryos were collected in 12 black cows. Among the collected embryos, 37 embryos (59.7%) could be transferred into recipients. These results would be used as the basic informations for changing patterns of hormonal level and blood biochemistry in Jeju black cow with superovulation.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.99-106
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• 1999

Ultra-high molecular weight polyethylene (UHMWPE) was crosslinked in the melt state to enhance wear resistance, Dicumyl peroxide (DCP) and triallyl cyanurate (TAC) was used as a crosslinking agent and a promoter, respectively. With increasing amount of DCP and TAC used, gel content of crosslinked UHMWPE (XUMPE) increased, while the melting temperature, crystallizaiton temperature, crystallinity, and tensile properties decreased. The results of pin-on-disk wear test and ball-on-disk test with small applied load showed reduced wear volumes of XUMPE from that of the unmodified UHMWPE. As the wear mechanism effected in the experimental condition of this study was thought to be deformation rather than adhesion or fatigue, a new parameter, the ratio of maximum contact stress to yield stress, was proposed to correlate well with observed wear resistance. In ball-on-disk wear test with larger applied load, XUMPE showed higher wear volumes than that of the unmodified UHMWPE which were accompanied with increased friction coefficients and surface roughness of the wear tracks. When contact stress was well above yield stress, the failure of XUMPE, as well as deformation, was thought to be much accelerated.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.48-57
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• 2009

The characteristics of physico-chemical factors and the species compositions of phytoplankton were investigated to analyze the marine ecosystem at the depths during summer in the coast of Dokdo (stations DOK1$\sim$3). The mean values of conductivity (32 mS cm$^{-1}$), total dissolved solids (45 mg L$^{-1}$), salinity (35.5 psu), total suspended solids (39 mg L$^{-1}$) were the highest in DOK1. The biomass (chl-${\alpha}$) of phytoplankton was the highest in the surface of station DOK1 (3.1 ${\mu}g$ L$^{-1}$). By means of physico-chemical factors (salinity, turbidity, chl-${\alpha}$, T-N, T-P and Si), the coast of Dokdo was estimated to be more polluted than the previous results in 2000. A total of 72 species in Dokdo were composed of 54 species (76.1%) for Bacillariophyceae and 13 species (18.3%) for Dinophyceae, 3 species (4.2%) for Chrysophyceae and 1 species (1.4%) for Cyanophyceae. The standing crops of phytoplankton were the highest (8.5 $\times$ 10$^4$ cells L$^{-1}$) at 20 m of station DOK1, while they were the lowest (1.65 $\times$ 10$^4$ cells L$^{-1}$) at 30 m of station 1. The dominance index was maximum (0.73) at 10 m of station DOK1 and was minimum (0.4) at 30 m of station 1. The diversity index was the highest (2.92) in the surface of station 2, while it was the lowest at 20 m (1.58). The dominant species of phytoplankton were Chaetoceros affinis (3.3 $\times$ 10$^4$ cells L$^{-1}$) at 20 m, Climacosphenia moniligera (2.8 $\times$ 10$^4$ cells L$^{-1}$) at 40 m and Melosira juergensii (1.7 $\times$ 10$^4$ cells L$^{-1}$) at 10 m of station DOK1. At the surface of station DOK2, the dominant species were Bacillaria paxillifer and Richelia intracellularis (1.4 $\times$ 10$^4$ cells L$^{-1}$, respectively), while it was Paralia sulcata (1.6 $\times$ 10$^4$ cells L$^{-1}$) at the surface of station DOK3. The station DOKl, where affected by upwelling, turbulence and convection due to the East Korean Warm Current, was the most eutrophicated water body in three stations. The monitoring of marine ecosystem in the coast of Dokdo should be continued to show the alternatives for water and species conservation and to purify the eutrophicated water body due to artificial pollutants as well as physico-chemical factors by the global warming, the climatic change, CO$_2$ etc.