• Journal of Dental Rehabilitation and Applied Science
• /
• v.22 no.1
• /
• pp.101-110
• /
• 2006

This study was performed to investigate the surface properties and in vitro biocompatibility of electrochemically oxidized Ti-6Al-7Nb alloy by anodic spark discharge technique. Discs of Ti-6Al-7Nb alloy of 20 mm in diameter and 2 mm in thickness were polished sequentially from #300 to 1000 SiC paper, ultrasonically washed with acetone and distilled water for 5 min, and dried in an oven at $50^{\circ}C$ for 24 hours. Anodizing was performed using a regulated DC power supply. The applied voltages were given at 240, 280, 320, and 360 V and current density of $30mA/cm^2$. Hydrothermal treatment was conducted by high pressure steam at $300^{\circ}C$ for 2 hours using a autoclave. Samples were soaked in the Hanks' solution with pH 7.4 at $36.5^{\circ}C$ during 30 days. The results obtained were summarized as follows; 1. The oxide films were porous with pore size of $1{\sim}5{\mu}m$. The size of micropores increased with increasing the spark forming voltage. 2. The main crystal structure of the anodic oxide film was anatase type as analyzed with thin-film X-ray diffractometery. 3. Needle-like hydroxyapatie (HA) crystals were observed on anodic oxide films after hydrothermal treatment at $300^{\circ}C$ for 2 hours. The precipitation of HA crystals was accelerated with increasing the spark forming voltage. 4. The precipitation of the fine asperity-like HA crystals were observed after being immersed in Hanks' solution at $37^{\circ}C$. The precipitation of HA crystals was accelerated with increasing the spark forming voltage and the time of immersion in Hanks' solution. 5. The Ca/P ration of the precipitated HA layer was equivalent to that of HA crystal as increasing the spark forming voltage and the time of immersion in Hanks' solution.

• Applied Biological Chemistry
• /
• v.23 no.4
• /
• pp.246-250
• /
• 1980

The effects of two Cytozyme complexes, Crop Plus and Seed Plus, applied to rice (variety: Jinheung) were evaluated during the 1980 rice growing season. Primary objectives were directed to determine the effects of rates, timing and method of application of the products on the yield of rice. For the Seed Plus test, seed was soaked in the diluted Seed Plus solution(1 : 100) for 24 hours just prior to sowing. The Crop Plus was diluted to 1 : 12 for seedling treatment. Seedling roots were immersed in the diluted solution for 3 hours before transplanting. Crop Plus spray applied at the rates of 450ml/ha or 900ml/ha when rice plants were in the panicle initiation, heading or tillering stage respectively to compare the effects of rates and timing of application. The weather was not favorable for rice growth during the growing season except the tillering stage. The foliar spray at the tillering stage was more effective than the spray at the panicle initiation, and the rates of 900ml/ha showed better results than 450ml/ha. Combination of seed treatment and foliar spray increased grain yield by 16% over untreated control plots.

• Korean Journal of Veterinary Research
• /
• v.44 no.4
• /
• pp.663-668
• /
• 2004

This study was conducted to investigate the effect of hyaluronic acid (HA) on prevention of abdominal adhesions depending on various concentrations thereof by inducing an abrasion experimentally in the cecum of rats. Each group was consisted of 10 rats, and 40 rats were divided into 4 groups comprising the saline treatment group, HA 0.4% treated group, 0.6% treated group, and 0.8% treated group. And abrasion was caused in the cecum by using dry gauze and thereby, adhesion was induced. On 7 days after the operation, adhesions of each region were evaluated into the range of 0-4. Significant difference was found in the adhesion score between the control group and each experimental group (P<0.05). Also, HA 0.4% treatment group showed the lowest adhesion score (P<0.05). In the light of the above results, HA 0.4% solution was more effective on prevention of adhesion than HA 0.6% and 0.8% solution.

• Korean Journal of Agricultural Science
• /
• v.46 no.4
• /
• pp.857-868
• /
• 2019

A flooded rice field is one of the significant sources of anthropogenic methane (CH₄) with the intensity of the emissions dependent on management practices. Incorporation of rice straw, which is one of the organic amendments, induces the increase of methane emissions during the flooding season. In this study, we measured of methane emission according to applications of rice straw in different soil textures during a cultivation period in 2017 and 2018. The fallow treatments were non application of rice straw (NA), spring plowing after spring spreading of rice straw (SPSA), spring plowing after previous autumn spreading of rice straw (SPAA), and autumn plowing after previous autumn spreading of rice straw (APAA). The SPSA treatment emitted the highest total methane from loam soil in both 2017 (596.7 CH₄ kg ha^-1) and 2018 (795.4 CH₄ kg ha^-1). The same trend was observed in silt clay loam soil; the SPSA treatment still emitted the highest amount of methane in both 2017 (845.9 CH₄ kg ha^-1) and 2018 (1,071.7 CH₄ kg ha^-1). The lowest emission among the rice straw incorporated plots came from the APAA treatment for both soil texture types in all the seasons. The conversion factors of the SPAA were 0.79 and 0.65 from the loam and silt clay loam soils, respectively. Relatedly, the conversion factors of the APAA were 0.71 and 0.43 from the loam and silt clay loam soils, respectively. The above observations mean therefore that incorporation of rice straw early in the fallow reduces methane emissions in the main rice growing season.

• Korean journal of applied entomology
• /
• v.41 no.2
• /
• pp.137-143
• /
• 2002

Grape phylloxera, Daktulosphaira vitifoliae(Fitch), is a destructive grape insect pest because it forms root galls and kills the plant by directly destroying root system. The effects of insecticide treatments were examined to establish the chemical control system of phylloxera, and the damage by this insect was investigated in grapevine yards. The treatments of 40kg carbofuran 3GR per ha and carbosulfan 20WP of 10$\ell$ (1,000$\times$) per tree successfully reduced phylloxera densities. After the insecticide treatments in early season, the phylloxera population rebuilt up again at harvest season. In a grapevine yard where two times of carbofuran treatment (mid-May and post-harvest treatment) were applied a year from 1998 to 2000, total yield per ha in 2000 showed an increase of 30% over that of 1998. But the yield in 2000 was low 20% compared to the average standard yield of Korean grapevine yards. In a grapevine yard without chemical treatment during the same years, total yield per ha in 2000 showed 53% reduction compared to that of 1998. Also, damaged vines by phylloxera abruptly increased from 3% in 1998 to 50% in 2000.

• Archives of Plastic Surgery
• /
• v.37 no.4
• /
• pp.340-345
• /
• 2010

Purpose: Recently, bioceramics have become popular as a substitute graft material for reconstruction of bony defect after trauma or tumor surgery. Among the bioceramic materials, hydroxyapatite (HA) is favored due to its biocompatibility. HA scaffold is composed of the interconnected reticular framework, macropores and micropores. Macropores play an important role in cell migration, nutrients supply and vascular ingrowth. On the other hand, a number of micropores less than $10{\mu}m$ form an irregular surface on HA scaffolds, which prevents the osteoblast from adhering and proliferating on the surface of HA scaffold. Methods: In this study, three different groups were designed for comparison. In the first group (group A), conventional method was used, in which HA pellet was applied without surface pretreatment. The second group (group B) was given a HA pellet that has been coated with crystalline HA solution prior to application. In the third group (group C), the same method was used as the second group, where the pretreated HA pellet was heated ($1250^{\circ}C$, 1 hour) before application. Osteoblast-like cells ($2{\times}10^4$/mL) were scattered onto every pellet, then they were incubated in 5% $CO_2$ incubator at $37^{\circ}C$ for twelve days. During the first three days, osteoblast cells were counted using the hemocytometer daily. ALP activity was measured on the 3, 6, 9 and 12 culture days using the spectrophotometer. Results: Under SEM, group A showed a surface with numerous micropores, and group B revealed more rough crystal surface. Group C revealed a fused crystal appearance and flattened smooth surface. In proliferation and ALP activity of osteoblast cells, group C showed better results compared to group B. Group A which lacks pretreatment of the surface showed less osteoblast proliferation and ALP activity than group C, but showed better results than group B. Conclusion: We found that crystallized HA with heat treatment method enhances the osteoblasts proliferation and differentiation on the surface of HA pellets.

• 한국초전도학회:학술대회논문집
• /
• 2007.07a
• /
• pp.73-73
• /
• 2007

• 한국초전도학회:학술대회논문집
• /
• v.15
• /
• pp.74-74
• /
• 2005

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.12 no.1
• /
• pp.180-186
• /
• 1990

This is a case report of first branchial cleft cyst in 56 year old male patient, which was tentatively diagnosed as acute right submandibular abscess resulted from the periapical lesion of the lower right second molar. The results are as follows, 1. The accompanying ipsilateral inflammatory swelling resulted from the periapical lesion of lower right second molar tooth makes the diagnosis difficult. 2. The onset of this case was very late in comparison to the mean discovering age of branchial cleft cysts. 3. The plain radiography using contrast media is helpful for the diagnosis of cystic lesions within soft tissues. 4. This case in a first branchial cleft cyst(Type I) which occurs less than 1% of all branchial cleft anomalies.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.12 no.2
• /
• pp.95-101
• /
• 1990

This is a case report of polyostotic fibrous dysplasia developed in the craniofacial region of 21 year old male patient, who had complained the buccolingual expansion of left mandibular body area, malocclusion and facial asymmetry. We could achieve satisfactory results by radical resection of the relatively well defined small lesion of mandible and by cosmetic bone shaving procedure on the widely dispersed and poorly defined lesions of cranium. But the persistent growth and recurrence of the lesions may produce loss of hearing, visual difficulties, facial paralysis and anosmia, and as it is a polyostotic type occured in the craniofacial region of male patient, the possibility of malignant degeneration should not be excluded completely and periodic recall and check up will be necessary.