• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.39-45
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• 2009

Statement of problem: Recently precalcification treatment has been studied to shorten the period of the implant. Purpose: This study was performed to evaluate the effect of precalcification treatment of $TiO_2$ Nanotube formed on Ti-6Al-4V Alloy. Material and methods: Specimens of $20{\times}10{\times}2\;mm$ in dimensions were polished sequentially from #220 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. The nanotubular layer was processed by electrochemical anodic oxidation in electrolytes containing 0.5 M $Na_2SO_4$ and 1.0 wt% NaF. Anodization was carried out using a regulated DC power supply (Kwangduck FA, Korea) at a potential of 20 V and current density of $30\;㎃/cm_2$ for 2 hours. Specimens were heat-treated at $600^{\circ}C$ for 2 hours to crystallize the amorphous $TiO_2$ nanotubes, and precalcified by soaking in $Na_2HPO_4$ solution for 24 hours and then in saturated $Ca(OH)_2$ solution for 5 hours. To evaluate the bioactivity of the precalcified $TiO_2$ nanotube layer, hydroxyapatite formation was investigated in a Hanks' balanced salts solution with pH 7.4 at $36.5^{\circ}C$ for 2 weeks. Results: Vertically oriented amorphous $TiO_2$ nanotubes of diameters 48.0 - 65.0 ㎚ were fabricated by anodizing treatment at 20 V for 2 hours in an 0.5 M $Na_2SO_4$ and 1.0 NaF solution. $TiO_2$ nanotubes were composed with strong anatase peak with presence of rutile peak after heat treatment at $600^{\circ}C$. The surface reactivity of $TiO_2$ nanotubes in SBF solution was enhanced by precalcification treatment in 0.5 M $Na_2HPO_4$ solution for 24 hours and then in saturated $Ca(OH)_2$ solution for 5 hours. The immersion in Hank's solution for 2 weeks showed that the intensity of $TiO_2$ rutile peak increased but the surface reactivity decreased by heat treatment at $600^{\circ}C$. Conclusion: This study shows that the precalcified treatment of $TiO_2$ Nanotube formed on Ti-6Al-4V Alloy enhances the surface reactivity.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.509-518
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• 2012

The objective of this study was to determine the effect of heat shock treatments on the phytochemicals including antioxidants and anticancer materials in kale (Brassica oleracea L. var. acephala) sprouts. In study I, kale sprouts grown under the growing system for four days were soaked at 40, 50, or $60^{\circ}C$ distilled water for 10, 30, or 60 seconds, and in study II, kale sprouts were soaked at $50^{\circ}C$ distilled water for 10, 20, 30, 45, or 60 seconds. After the heat shock treatments, the sprouts were transferred into normal growing conditions and recovered there for two days. Fresh and dry weights, electrolyte leakage, total phenolic concentration, antioxidant capacity, total flavonoid concentration, phenylalanine ammonia-lyase (PAL) activity, and glucosinolates content of the sprouts were measured before and after the heat shock treatments. As a result, there was a significant decrease in the fresh and dry weight of kale sprouts treated with heat shock compared with control at harvest in study I. Especially, heat shock at $60^{\circ}C$ lead to more pronounced growth inhibition compared with heat treatments at 40 and $50^{\circ}C$. Electrolyte leakage by cell collapse was the highest in the sprouts exposed to $60^{\circ}C$ distilled water, which agreed with the growth results. Heat shock at $50^{\circ}C$ significantly induced the accumulation of phenolic compounds. In study II, fresh weight of kale sprouts at $50^{\circ}C$ heat shock showed a significant decrease compared with the control at one and two days after the treatment. However, the decrease was minimal and dry weight of kale sprouts was not significantly different from that in control. In contrast, the heat shock-treated kale sprouts had higher level of total phenolic concentration than control at harvest. Heat shock treatments at $50^{\circ}C$ for 20 seconds or more showed at least 1.5 and 1.2 times higher total phenolic concentration and antioxidants capacity than control, respectively. The change of the total flavonoid concentration was similar with that of antioxidants. PAL activity after 24 hours of heat shock was higher in all the heat shock-treated sprouts than that in control suggesting heat shock may stimulate secondary metabolic pathway in kale sprouts. Seven glucosinolates were identified in kale sprouts and soaking the sprouts with $50^{\circ}C$ water for 20 seconds had a pronounced impact on the accumulation of total glucosinolates as well as two major glucosinolates, progoitrin and sinigrin, at harvest. In conclusion, this study suggests that heat shock using hot water would be a potential strategy to improve nutritional quality of kale sprouts by inducing the accumulation of phytochemicals with antioxidant and anticancer properties.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.71-77
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• 1984

A study on the stability of chlorophyll a in Undaria pinnatifida during blanching, salting and storage was carried out. Raw Undaria pinnatifida was blanched for 25 seconds in the temperature range of 70 to $100^{\circ}C$. To stabilize the chlorophyll a some chemicals such as 1% solutions of $Ca(CH_3CO_2)_2,{\;}Ca(OH)_2,{\;}MgCO_3,{\;}0.5%{\;}Ca(CH_3CO_2)_2$ with $0.5%{\;}MgCO_3$, and reed ash solution were used during/after blanching. The blanched product was salted with table salt after centrifuging for 2 minutes at 1500 rpm, and then again centrifuged after 48 hours for dewatering. The product which was mixed with 8% of table salt was sealed in a polyethylene film bag and stored at 10, 20, 30 and $40^{\circ}C$. The most effective blanching temperature for maximal residual amount of chlorophyll a was $85^{\circ}C$. The quantities of total organic and volatile acids were not significantly changed by the blanching temperature. Blanching in 1% chemical solutions showed bitter results than soaking in 1% chemical solutions for 20 minutes after blanching without chemicals. Reed ash and 0.5% $Ca(CH_3CO_2)_2$ with 0.5% $MgCO_3$ solutions were more effective than the 1% solutions of other chemicals, but the effect was not significant, compared with the group not treated with chemicals. The most reasonable ratio of added salt to dewater the product for 48 hours was 30% in w/w. The amount of total organic and volatile acids revealed no correlation with the amount of added salt. Color and odor of salted product was not severely changed during the storage of 77 days at $10^{\circ}C$. But the changes were accelerated with increasing storage temperatures. The degradation of chlorophyll a in salted product during storage could be interpreted as a first order reaction, and the rate constants at 10, 20, 30 and $40^{\circ}C$ were 0.1289, 0.1028, 0.0770 and 0.0550, respectively. $Q_{10}$ and the activation energy were 1.33 and 5.01 Kcal/g mole.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.132-143
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• 1992

The study was conducted to find out synergistic effects by interaction on the basis on anatomical changes between paddy rice and weed species by mixture use of oxyfluorfen and bensulfuron at 0, $10^{-6}$ and $10^{-4}$M, respectively. Tissues were sampled at 72 hrs after soaking treatment and prepared for light microscopic examination and sectioned longitudinally and transversely stem into $8{\mu}m$ thick. As the results of microscopic examination, the major response of treated plant involved rupture and constrict in mesophyll cells and epidermal cells, and shrinks in bundle sheath cells by oxyfluorfen and disorganization and swelling in meristems by bensulfuron. Anatomical changes in rice was the least affected by even high concentration and two herbicide mixtures, whereas Echinochloa crus-galli was severely disorganized in meristem regions and ruptured in epidermal cells by mixture use. Monochoria vaginalis was completely ruptured by any treatment concentrations and mixtures. Scirpus juncoides was considerably tolerant to both herbicides and their mixture and was similar to those that occur in rice. Perennial weed, Sagittaria pigmaea was observed vacuolation, non-nucleation of cell, and irregular cell layering but in mixture injury was slight. Cyperus serotinus was severely shrunk and ruptured by mixture treatment. Eventually anatomical variations in all weed species was shown synergistic effect by use of herbicide mixtures.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.56-64
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• 2021

This study was conducted to examine the effect by different types and concentrations of auxin on the rooting and growth of strawberry (Fragaria × ananassa Duch. cv. Maehyang) cuttings in the greenhouse. The NAD (1-naphthylacetamide), IBA (indole-3-butyric acid), and IAA (3-indoleacetic acid) were applied with a 1 hour soaking as 50, 100, 150, and 200 mg·L-1, respectively. The non-treatment was set as the control. The cuttings of strawberry were transplanted in the strawberry seedling tray filled with coir medium on June 4, 2020. The humidification was carried out for 2 weeks. The average relative humidity, daytime temperature, and nighttime temperature inside the humidification tunnel was 63.4 ± 15%, 29.3 ± 5℃, and 16.2 ± 5℃, respectively. There was no significant difference in rooting rate on the control, IBA, and IAA treatments. However, significantly low rooting rates were observed in NAD treatments. The survival rates were significantly higher in the control and IBA with 50 mg·L-1 than in other treatments. The number of leaves was the highest in IBA with 100 mg·L-1. The root length was the longest in the control. More number of roots were counted in IAA with 100 and 150 mg·L-1. The dry weight of root was the heaviest in the control. The total root length, root surface, number of root tips, and number of root forks were significantly higher in the control. As a result, control, IAA, and IBA showed similar shoot and root growth. However, NAD showed the worst root and shoot growth. Consequently, compared with IAA and IBA, NAD was not appropriate plant growth regulator of rooting for cutting propagated strawberries.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.87-96
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• 1995

We examined the effects of seed treatment on field germination rate and seedling growth for four woody species, Euonymus alatus, Thea sinensis, Zanthoxylum piperitum, Nandina domestia which are economically useful in Korea. The seeds of each species were purified carefully after collection during Oct. and Nov.. E. alatus, T. sinensis, and Z. piperitum were sowed in the experimental field after stored in open ground with treatment of Pon-Pon. $H_2O_2$, $GA_3$, scarification. and N. domestica was sowed in container within green house after treatment of three different periods(7, 15, 21days) in growth chamber(4, 25, $32^{\circ}C$). Germination rate and seedling growth were measured in mid-Oct.. In E. alatus germination rate was higher in storaging in open ground after soaking in $GA_3$(67.1%) than in only storaging in open ground(18.4%). But the rate in T. sinensis showed no differences between storage in open ground after treatment of $GA_3$, and scarification, and only storage in open ground, Germination rate of Z. piperitum was much higher in storaging in open ground after treatment of Pon-Pon(80.3%) than in only storaging in open ground(12.4%). In N. domestica. seeds stored for 7 days at $32^{\circ}C$ were germinated faster than those stored for 7 days at $4^{\circ}C$, and germination rate of the former was also higher than that of the latter. Peak Times of seed germination in field were order of E. alatus (32 days). Z. piperitum (49 days). T. sinensis (83 days), N. domestica (87 days). The growth of seedling germinated in field showed a good result because of early germination following the effect of seed treatment. The periods of highest growth performances of the seedlings were 72 days in late Jun.-mid Jul. in E. alatus. 59 days in late Jun.- mid Jul. in Z. Piperitum, and 45 days in mid Aug.- mid Sep. in T. sinensis.