• Applied Biological Chemistry
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• v.26 no.2
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• pp.132-136
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• 1983

The indole-3-acetic acid(IAA) oxidase activity of shoot and root tips of etiolated pea seedlings (Pisum sativum L. var. Sparkle) during and after chilling was determined. The IAA oxidase level of root tips was 4 to 15 times as high as that of shoot tips. During chilling the seedlings apical and subapical 5 mm shoot sections increased in IAA oxidase activity but apical and subapical 5 mm root sections decreased. When chilled plants were returned to $25^{\circ}C$ to recover, the enzyme activity had a tendency to restore to the activity level of controlled plants.

• Polymer(Korea)
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• v.33 no.1
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• pp.19-25
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• 2009

New polyelectrolytes derived from ionene-containing photocurable reactive oligomer (PIDM) were prepared for water-resistant humidity-sensitive membranes. The mixture of PIDM, hexamethylene dimethacrylate (HDM), pentaerythritol triacrylate dimer (SP1013), and photoinitiator was simultaneously coated on the sensor electrode with photoinitiated radical polymerization. The pretreatment of the substrates with vinyl-type silane-coupling reagent was performed for improving the water durability and stability of the sensors at high temperature and humidity. When the resistance dependences on the relative humidity of the crosslinked PIDMs were measured, it was found that the resistance varied three orders of magnitude between 20 and 90%RH, which was required for the humidity sensor operating at ambient humidity. Their hysteresis, temperature dependence, response time, water durability, and high temperature/humidity stabilities were measured and evaluated as a humidity-sensing membrane.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.244-250
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• 2021

Purpose: The purpose of this study was to examine effects of culture conditions on the growth and antibacterial activity of Streptococcus salivarius K12. Materials and Methods: S. salivarius K12 was cultivated in medium containing animal and plant protein or in medium of neutral and acidic conditions. The growth of S. salivarius K12 was measured every 2 hours by a spectrophotometer. The antimicrobial activity of S. salivarius K12 against Streptococcus mutans and Porphyromonas gingivalis was investigated by the susceptibility assay using the spent culture medium. Results: the growth of S. salivarius K12 showed faster in medium containing plant protein and neutral pH condition. The antimicrobial and antifungal activity of S. salivarius K12 appeared stronger in medium containing plant protein than animal proteins. Conclusion: For application of S. salivarius K12 to bacterial oral disease, co-substances may be needed for S. salivarius K12 to colonize in the oral cavity and enhance the antimicrobial activity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.33-38
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• 2022

Ultraviolet B (UVB) damages DNA residues in skin keratinocytes. In particular, the formation of cyclobutane pyrimidine dimers (CPD), a pyrimidine residue damage in DNA, is considered a representative indicator of skin photoaging. In this study, we confirmed defensive effect of Glycyrrhiza glabra (G. glabra) extract against UVB induced DNA damage. First of all, we confirmed UVB dependent amount of CPD formation in human keratinocyte cell line. UVB induced CPD was decreased by G. glabra extract by dose dependent manner. In addition, it was confirmed that the expression of mRNA of DNA damage recovery factors was increased by G. glabra extract. Consequently, through this study, it was possible to confirm the DNA protection effect of G. glabra extract in skin keratinocytes.

• Asian Journal of Turfgrass Science
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• v.19 no.1
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• pp.1-16
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• 2005

This study was conducted to effect a complex fertilizer treatment on a recovery of damaged turfgrass caused by competing with tree at area under trees, and to seek for effective management system on damaged areas under trees in golf courses. Available phosphorous and potassium were enough to grow up turfgrass in plots of East valley and Ji San Golf Club. But these plots were acid soil ranged from pH 5.3 to pH 5.5, so that lime fertilizer was required for improving the chemical of soil. The effect on complex fertilizer showed significant f3r the recovery of damaged turfgrass. Turfgrass recovery ratio by complex fertilizer was better in low-density(LD) section of fertilizer than in high-density(HD) section of control. As the result of surveying turfgrass characters according to dates, dry matters in HD sections of control plots were higher than these in LD sections of fertilizer plots in 6 Aug. before sprinkling a complex fertilizer. But dry matters in LD section of fertilizer were, on the contrary, higher than in 6 Sep. after sprinkling complex fertilizer. In view of the result so far conducted, a turfgrass recovery to LD sections of complex fertilizer was batter than that of HD sections of control. Sprinkling complex fertilizer on turfgrass damaged by competing with trees will maintain the turfgrass growth, even though happen to compete between trees and turfgrass.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.67-78
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• 2012

The purpose of this study was to determine whether there were differences in shear bond strength to human dentin using IDS technique compared with DDS. Forty freshly extracted human molars were and devided into 4 groups. The control group specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent and cemented with resin cement. The IDS/SE(immediate dentin sealing, Clearfil$^{TM}$ SE Bond) and IDS/SB (immediate dentin sealing, Adapter$^{TM}$ Single Bond 2) specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent(Clearfil$^{TM}$ SE Bond and Adapter$^{TM}$ Sing Bond 2, respectively), whereas DDS specimens were not treated with any dentin bonding agent. IDS/SE, IDS/SB and DDS specimens were thermocycled. Following that delay, specimens were cemented with resin cement. The dentin bonding agent was left unpolymerized until the application of porcelain restoration. Shear bond strengths were measured using a universal testing machine. Specimens also were evaluated for mode of fracture using an optical microscope. The mean shear bond strengths of control group and IDS/SE groups were not statistically different from one another. The bond strength of IDS/SE group had a significantly higher mean than that of DDS group. There was no significant difference in the mean shear bond strength between IDS/SB(4.11MPa) and DDS group. The evaluation of failure modes indicates that most failures in the control group and IDS/SE groups were mixed, whereas failures in the DDS group were interfacial. When preparing teeth for indirect ceramic restoration, IDS with Clearfil$^{TM}$ SE Bond results in improved shear bond strength compared with DDS.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.11-24
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• 1979

To characterize elastic and plastic chilling injury, rice seedlings grown at 28/$16^{\circ}C$ day/night temp. under 20K lux (13hrs.) in a phytotron were subjected to a 11/$6^{\circ}C$, 20K lux condition for 2, 4, 6 or 8 days at 1, 2, 3, 4 or 5th leaf-stage, respectively, followed by further growth under 28/$16^{\circ}C$condition till 30th day after seeding. Japonica variety Jinheung and Chulwon No.1 survived almost 100% without any significant , discoloration and death of leaves due to chilling even under the chilling of 8 days at all seedling ages tested. Tongil and Yushin, varieties from Indica x Japonica cross, showed increasing discoloration of leaves and death of plants with increase in chilling intensity. The longest chilling duration shown seedling death less than 5% was 4, 6, 1, 4, 8 days for Tongil, and 6, 6, 1, 2, 2, days for Yushin at 1, 2, 3, 5th leaf-stage, respectively. The degree of discoloration and death of leaves or suppression of height growth was not explicitly related to seedling death or the dry weight reduction. The degree of seedling death or dry weight reduction could differentiate chilling tolerance of varieties and seedling ages, but somewhat differently. Reduction in dry weight due to chilling occurred even without any visible injury or seedling death. These suggest that both the degree of seedling death and reduction in dry weight should be considered in the test of varieties for chilling tolerance. Combined evaluation of seedling death and dry weight reduction indicated the most susceptible seedling age to chilling injury to be 1 to 2nd leaf-stage for Jinheung, 2 to 3rd leaf-stage for Chulwon No.1, 3rd leaf- stage for Tongil and Yushin, respectively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.421-429
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• 2003

Purpose : Neoadjuvant chemotherapy is commonly used to treat cancer patients as adjunct treatment, but if the microvascular tissue transfer is performed simulataneously with cancer resection surgery, the induction chemotherapy might affect the survival rate of vascularized free flap. Our study will focus on the effect of induction chemotherapy on the free flaps which were made on white rat abdomen after injection of 5-FU. Materials and Methods: The experimental rat groups were divided into three groups (total 24 rats) as a normal control group, 24 hrs group after 5-FU injection, 3 days group after 5-FU injection. Inferior abdominal island flaps of 8 Sprague Dawley rats on each group were made and immediately were induced into an ischemic state by clamping the supplying inferior epigastric artery and vein with microvascular clamp for a hour to induce a similiar free flap circumstance, then the inferior abdominal skin flaps were reperfused by releasing the clamps. The flaps on abdomen were repositioned and sutured. The experimental data for flap survival rate was collected by digital photo taking, analysed by computer image program to compare with the flap luminosity. The rats were sacrificed at 3 days, 5 days, 7 days after flap preparation and specimens of the flap were taken and stained with H-E staining. The microscopic finding was made under magnification of 200 and 400. Results: 1. Gross findings on each groups showed the healing condition was good as following sequences; normal, 24 hrs group after chemotherapy, 3 days group after chemotherpy. 2. The values of flap luminosity for evaluation of flap survival rate also showed the same sequences as gross findings of healing state. 3. The microscopic findings of epidermis necrosis, inflammation state, dermis fibrosis, vessel change, fatty tissue layer thinning were compared with each group. The 3 days group after chemotherapy showed remarkably poor healing condition compared to other groups. Conclusion: Chemotherapy agents affected the healing process of free flap, but healing condition was recovered spontaneously as post-injection periods passed out. In opposite to our expectation, 3 days group showed the bad flap condition in comparing with 24 hours group which was considered as immatured body circulation state of chemotherapy agent. It showed that 3 weeks in human being after chemotherapy was not proper as timing of microvascular tissue transfer if 3 days group in rat was considered as same healing period of 3 weeks in human being. More delayed healing timing than 3 weeks might be required in clinical application of free tissue transfer.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.105-112
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• 2008

The purpose of this study was to evaluate the contact angle made by 3 kinds of self etching primers (Clearfil SE Bond, AdheSE, and Tyrian) on dentin and to measure the microtensile bond strength of resin composite to dentin using these self-etching primers. Contact angle between each of 3 self etching primers and polished dentin surface was measured (n=30) by contact angle analyzer and the result was analyzed by One-way ANOVA. For the measurement of microtensile bond strength, polished dentin surface was treated with each of 3 self etching primers and dentin adhesives. Z-250 composite resin was built-up with a height of 5 mm on the adhesive-treated surface and light cured for 40s with a halogen light curing unit. Thereafter, each tooth was sectioned into slabs perpendicular to the bonded interface and trimmed (n=45). The microtensile bond strength was measured with universal testing machine and the result was analyzed with Kruskal-Wallis test. AdheSE group showed the highest contact angle followed by Clearfil SE group and Tyrian group (p<0.05). AdheSE group and Clearfil SE group showed significantly higher microtensile bond strength than Tyrian group (P<0.05).

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.1-9
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• 2013

This study examined the effects of the occlusal stability and a partial coverage mouthguard on physical fitness and motor capacity to determine the importance of the occlusal stability as a possible action mechanism of mouthguards on physical performance. Twenty physical education students were included for measurements of their handgrip strength, back strength, whole body reaction time, flexibility, sidestep test, stork stand test and jumping test according to the following 5 different occlusal conditions: mouth closed position without a mouthguard, with a full coverage mouthguard, with a right partial coverage mouthguard, with a left partial coverage mouthguard and with anterior partial mouthguard. The results revealed no significant difference in any of the measured physical factors between the occlusal conditions with and without a full-coverage mouthguard. On the other hand, a significant difference was observed in whole body reaction between the occlusal conditions with and without the partial coverage mouthguards. Therefore, isokinetic muscle tests on both knee joints and the Wingate anaerobic power test should be performed under the following five occlusal conditions: with or without full-coverage maxillary custom-made mouthguard, with a unilateral right or left partial-coverage maxillary mouthguard and with an anterior partial-coverage maxillary mouthguard. These results suggest that the partial coverage mouthguard had a short-term beneficial effect on agility rather than full coverage mouthguard.