• Asian Journal of Turfgrass Science
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• v.9 no.3
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• pp.253-260
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• 1995

This study is aimed to understand the effects of temperature, light and GA soaking treatment on the seed germination of perennial ryegrass 'Dandy', creeping hentgrass 'Penlinks', tall fescue 'Arid' and Kentucky hluegrass 'Nasaw'. These experiments are carried in vitro, and their results obtained are summarized as the followings ; The optimum temperature for seed germination of perennial ryegrass 'Dandy' was found to he ranged at 20~30$^{\circ}C$, and the optimum temperature for germination of creeping bentgrass 'Penlinks', tall fescue 'Arid' and kentucky bluegrass 'Nasaw' seeds was found to be ranged at 20~25$^{\circ}C$, whereas the germination percentage under the below or above temperature of this range decreased. The germination of perennial ryegrass 'Dandy' and tall fescue 'Arid' seeds showed no effect on light, and while the germination percentage of creeping hentgrass 'Penlinks' increased more highly under the dark condition than under the light condition. The germination percentage decreased according to the higher temperature. The germination of Kentucky bluegrass 'Nasaw' seeds increased more highly under the dark condition than under the light condition at 20~25$^{\circ}C$, whereas the germination percentage under the dark condition at 15$^{\circ}C$ and 30$^{\circ}C$ decreased. In case of GA soaking treatment of seeds, all the cool season turfgrasses tested showed their own promoting effects on seed germination. The early germination of tall fescue 'Arid' was good without the soaking times. Creeping bentgrass 'Penlinks' and perennial ryegrass 'Dandy' had re-spectively the highest germination percentage at 10min and 1hr soaking treatment, and the longer the soaking time, the lesser the germination percentage. Kentucky bluegrass 'Nasaw' obtained the best results at 24has soaking treatment, and the longer the soaking time, the better the ger-mination percentage.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.1-8
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• 1990

The experiment was conducted to study on the germination of seeds, and chemical change in the endorsperm and embryo of maize seeds treated with gibbrellic acid(GA) 25, G A 50, bengyl adenine(BA) 100 and B A 200 ppm. Obtained results can be summerized as follows: 1. The germination rate in the initial stage of maize seed increased most with G A 25 ppm treated but decreased most with B A 200 ppm treatment amount other treated blocks. There is no significant difference between treatments in the middle and later stage of the seed germination. 2. The quantity of Q $CO_2$ was noticeably increased together in parallel with germination at each blocks, but such fact was found that the block of treatment has low Q $CO_2$ in comparison with control and in particular, has the tendency to take very low in B A 200 ppm. 3. The amount of reducing sugar and total sugars among embryo and endosperm are promptly increased at each blocks, but B A treatment shows low rate of increase in comparison with the non treatment and G A treatment. 4. The quantity of crude protein of seed during germination are increased at the part of embryo and decreased at the part of endosperm. Such degree is most prominent in the treatment with G A 25 ppm and changing degree of treatment with 200 ppm is lowest.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.290-295
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• 1998

Presowing treatements to seed are reasonable for elevating the seedling production efficiency. This experiment was carried out to determine the effects of $GA_3$ [0 (water) : 0.01 mM] and light qulaity (red : white) simultaneously treated before sowing on seedling emergence and growth of tobacco (Nicotiana tabacum L.) cv NC 82 and Burley 21. Red or white light was illuminated 12 hours a day while seeds of the cultivars were imbibed with either water or $GA_3$ 0.01 mM for 3 days. Seedling emergence was measured up to 20 days after sowing but morphological characters and dry weights were done 40 days. The seedling emergence rate of cv NC 82 was more affected by light quality and $GA_3$ pretreatments than that of cv Burley 21. Light quality more influenced the rate than $GA_3$ while red light or water imbibition enhanced the rates of the two cultivars compared to the other treatement. Although mean plant height and leaf number per seedling were nearly equal between the treatements, red light declined leaf area per seedling of cv Burley 21 of which seeds were imbibed in water but white light decreased the areas of both cultiars of which seeds were soaked in $GA_3$solution. Shoot dry weight was greater in cv NC 82 but less in cv Burley 21 pretreated with red light, and root dry weight showed the reverse result in white light, meaning that presowing light and $GA_3$ treatments could be changed the seedling development and growth of tobacco.

• Korean Journal of Materials Research
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• v.2 no.5
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• pp.360-365
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• 1992

Ga-doped polycrystalline ZnO films on glass substrates were prepared by sputtering the targets, which had been prepared by sintering discs consisting of ZnO powder and various amounts of G$a_2O_3$, to investigate the effects of gallium doping and sputtering conditions on electrical properties. Optimizing the RF power density, argon gas pressure and gallium content, transparent Ga-doped ZnO films with resistivity less than 1$0^{-3}$ohm-cm are obtained. Electron concentration of undoped and Ga-doped ZnO films are order of $10^{18}$, $10^{21}$/c$m^2$respectively. After heat treatment in air and $N_2atmosphere, $ the resistivity of Ga-doped ZnO films increases by about two orders of magnitude. The optical transmission is above 80% in the visible range and the optical band widens as the Ga content increases.

• ETRI Journal
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• v.38 no.4
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• pp.675-684
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• 2016

This paper demonstrates the effect of fluoride-based plasma treatment on the performance of $Al_2O_3/AlGaN/GaN$ metal-insulator-semiconductor heterostructure field effect transistors (MISHFETs) with a T-shaped gate length of $0.20{\mu}m$. For the fabrication of the MISHFET, an $Al_2O_3$ layer as a gate dielectric was deposited using atomic layer deposition, which greatly decreases the gate leakage current, followed by the deposition of the silicon nitride layer. The silicon nitride layer on the gate foot region was then selectively removed through a reactive ion etching technique using $CF_4$ plasma. The etching process was continued for a longer period of time even after the complete removal of the silicon nitride layer to expose the $Al_2O_3$ gate dielectric layer to the plasma environment. The thickness of the $Al_2O_3$ gate dielectric layer was slowly reduced during the plasma exposure. Through this plasma treatment, the device exhibited a threshold voltage shift of 3.1 V in the positive direction, an increase of 50 mS/mm in trans conductance, a degraded off-state performance and a larger gate leakage current compared with that of the reference device without a plasma treatment.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.36-43
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• 2022

This research was conducted to develop a seed propagation protocol for the use of Broussonetia kazinoki Siebold ex Siebold & Zucc, which native to East Asia. Light and temperature conditions, GA₃ treatment, and low-temperature stratification were performed to evaluate the germination characteristics. The germination percentage at 4, 15/6, 20/10 and 25/15℃ was 0, 42. 5, 44. 4 and 91.7%, respectively. Thus, the optimal germination temperature of the B. kazinoki seeds was 25/15℃. Although germination was delayed by relatively low temperature conditions, GA3 treatment allowed for increased germination rates even under the low temperature conditions. Cold stratification reduced time to germination. Relatively low germination percentages at 20/10℃ and 15/6℃ indicated that the seeds had been under the state of conditional dormancy. Through this study, B. kazinoki seeds have conditional dormancy because they can be germinated through GA₃ treatment even under relatively low temperature conditions and it is judged that it will support the commercial propagation practice in the future.

• YAKHAK HOEJI
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• v.55 no.1
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• pp.39-44
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• 2011

Many reports indicate that $18{\beta}$-glycyrrhetinic acid ($18{\beta}$-GA) from Glycyrrhizae Radix has anti-inflammatory and immunoregulatory activities, whereas reports regarding anticancer activity of the compound are few. In present study, we investigated antitumor effect of $18{\beta}$-GA on tumor caused by A549 cancer cell in mice. Data resulting from the cytotoxicity assay showed that $18{\beta}$-GA caused killing of A549 cells. $LD_{50}$ values of $18{\beta}$-GA were app. 180 ${\mu}M$ and 80 ${\mu}M$, corresponding to 48 hr- and 72 hr-treatments, displaying that the killing activity was more effective as the $18{\beta}$-GA treatment was prolonged. Based on these data, antitumor effect of $18{\beta}$-GA was tested in nude mice. For induction of the tumor, A549 ($3{\times}10^6$ cells/mouse) was injected subcutaneously into the lateral abdomen of nude mice (Balb/c nu/nu). To determine the antitumor effect, nude mice with tumor were given $18{\beta}$-GA (1 mg/200 ${\mu}l$/mouse) intraperitoneally every three days for four times. Tumor-sizes were measured with a caliper for a period of 24 days. Results showed that the $18{\beta}$-GA treatment reduced the tumor-sizes (P<0.05) as compared with negative control nude mice that received diluent (DPBS). The reduction degree was greater than reduction degree by doxorubicin (60 ${\mu}g$/mouse), and the pattern of reduction was almost sustained during the entire period of the observation. In conclusion, our studies demonstrate that $18{\beta}$-GA has antitumor activity to the A549 cancer cell-caused tumor.

• Journal of the Optical Society of Korea
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• v.18 no.3
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• pp.283-287
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• 2014

Square lattice nano-hole arrays with diameters and periodicities of 200 and 500 nm, respectively, are fabricated on InGaN/GaN blue light emitting diodes (LEDs) using electron-beam lithography and inductively coupled plasma reactive ion etching processes. Cathodoluminescence (CL) investigations show that light emission intensity from the LEDs with the nano-hole arrays is enhanced compared to that from the planar sample. The CL intensity enhancement factor decreases when the nano-holes penetrate into the multiple quantum wells (MQWs) due to the plasma-induced damage and the residues. Wet chemical treatment using KOH solution is found to be an effective method for light extraction from the nano-patterned LEDs, especially, when the nano-holes penetrate into the MQWs. About 4-fold CL intensity enhancement factor is achieved by the KOH treatments after the dry etching for the sample with a 250-nm deep nano-hole array.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.170-176
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• 2008

Background: Bioprosthetic devices for treating cardiovascular diseases and defects may provide alternatives to autologous and homograft tissue. We evaluated the mechanical and physical conditions of a porcine pericardial bioprosthesis treated with Glutaraldehyde (GA), Ethanol, or Sodium dodecylsulfate (SDS) before implantation. Material and Method: 1) Thirty square-shaped pieces of porcine pericardium were fixed in 0.625%, 1.5% or 3% GA solution. 2) The tensile strength and thickness of these and other bioprosthesis, including fresh porcine pericardium, fresh human pericardium, and commercially produced heterografts, were measured. 3) The tensile strength and thickness of the six treated groups (GA-Ethanol, Ethanol-GA, SDS only, SDS-GA, Ethanol-SDS-GA and SDS-Ethanol-GA) were measured. Result: 1) Porcine pericardium fixed in 0.625% GA the thinnest and had the lowest tensile strength, with thickness and tensile strength increasing with the concentration of GA solution. The relationship between tensile strength and thickness of porcine pericardium increased at thicknesses greater than 0.1mm (correlation-coefficient 0.514, 0<0.001). 2) There were no differences in tensile strength or thickness between commercially-produced heterografts. 3) Treatment of GA, ethanol, or SDS minimally influenced thickness and tensile strength of porcine pericardium, except for SDS alone. Conclusion: Porcine pericardial bioprosthesis greater than 0.1 mm thick provide better handling and advantageous tensile strength. GA fixation did not cause physical or mechanical damage during anticalcification or decellularization treatment, but combining SDS-ethanol pre-treatment and GA fixation provided the best tensile strength and thickness.

• Korean Journal of Plant Resources
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• v.6 no.2
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• pp.135-140
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• 1993

This study was attempted to establish the propagation and cultivation methods of Rhodiola elongata Fisch. et Mey. as a part of development of northern plant resources. Seeds were treated and investingated at the 15, 20, 25$^{\circ}C$ and 100, 200, 400, 800ppm of the growth regulator $GA_3$, BA, and Kinetin. The results obtained are summarized as follows: Seeds of R. elongata were the most vigorously germinated at 15-20$^{\circ}C$, and rate of germination at 25$^{\circ}C$ decreased gradually. Germination rate of seeds that treated growth regulators was remarkably increased than non-treated ones, and $GA_3$ treatment among the growth regulators showed the best effects. The effective concentration of $GA_3$ for germination of R. elongata seeds was 400 ppm.