• Analytical Science and Technology
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• v.10 no.4
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• pp.240-245
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• 1997

An accurate analysis method for the determination of lead in whole blood by ICP/MS was developed. Whole blood samples were decomposed in microwave digestion system without any contamination and loss of lead. The 96 samples were analyzed by ICP/MS using mass$^{208}$ isotope of lead. Lead concentrations of human whole blood were ranged of $2.50{\sim}22.8{\mu}g/dL$. The accuracy of this analysis method was verified by analyzing of NIST SRM 955a series(lead in blood).

• Korean Journal of Plant Resources
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• v.16 no.1
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• pp.34-39
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• 2003

Corm apical meristem cultures of thirteen glasshouse freesia cultivars were tested to investigate the possibility of micropropagation using MS basal medium supplemented with 2,4-D, NAA(0.1, 0.5, 1.0mg/L, respectively) and BA (0.5∼2.0mg/L). The majority of the tested cultivars could be induced callus and shoot buds in all culture condition. The combinations of NAA and BA appeared superior to that of 2,4-D and BA depending on cultivars for callus induction and shoot formation. Among the cultivars, 'Golden Yellow' showed the highest regeneration capacity on MS media with 0.5mg/L NAA and 1.0 mg/L BA. The highest percentage of regeneration and the greatest number of shoot from calli were obtained through successive subculture on MS medium supplimented with 0.5mg/L BA. In that condition, more than 60 ％ shoot regeneration and average of 25.1 shoots per explant was achieved. Transformed shoots on half-strength MS medium without plant growth regulators rooted easily.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.157-161
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• 1999

This study was performed to enhance the proliferation rate of Gladiolus 'Topaz' callus. The callus was induced from the cermet tissue explants on MS solid medium with 10 mg/L 2,4-D. In the case of liquid shaking culture, proliferation of the callus was effective in MS medium with 0.05 mg/L 2,4-D at 2$0^{\circ}C$ under 16 hours daylength and in a 100 mL Erlenmeyer flask containing 20 mL of the liquid medium and at 75 rpm in rotation speed of the horizontal shaking culture. Furthermore the callus was also able to be subcultured in the same liquid medium.

• Progress in Medical Physics
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• v.10 no.1
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• pp.33-40
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• 1999

Purpose: To simulate and measure the signal intensity of various tissues near bone interface in 2D and 3D neurological MR images. Materials and Methods: In neurological proton density (PD) weighted images, every component in the head including cerebrospinal fluid (CSF), muscle and scalp, with the exception of bone, are visualised. It is possible to acquire images in 2D or 3D. A 2D fast spin-echo (FSE) sequence is chosen for the 2D acquisition and a 3D gradient-echo (GE) sequence is chosen for the 3D acquisition. To find out the signal intensities of CSF, muscle and fat (or scalp) for the 2D spin-echo(SE) and 3D gradient-echo (GE) imaging sequences, the theoretical signal intensities for 2D SE and 3D GE were calculated. For the 2D fast spin-echo (FSE) sequence, to produce the PD weighted image, long TR (4000 ms) and short TE$_{eff}$ (22 ms) were employed. For the 3D GE sequence, low flip angle (8$^{\circ}$) with short TR (35 ms) and short TE (3 ms) was used to produce the PD weighted contrast. Results: The 2D FSE sequence has CSF, muscle and scalp with superior image contrast and SNR of 39 - 57 while the 3D GE sequence has CSF, muscle and scalp with broadly similar image contrast and SNR of 26 - 33. SNR in the FSE image were better than those in the GE image and the skull edges appeared very clearly in the FSE image due to the edge enhancement effect in the FSE sequence. Furthermore, the contrast between CSF, muscle and scalp in the 2D FSE image was significantly better than in the 3D GE image, due to the strong signal intensities (or SNR) from CSF, muscle and scalp and enhanced edges of CSF. Conclusion: The signal intensity of various tissues near bone interface in neurological MR images has been simulated and measured. Both the simulation and imaging of the 2D SE and 3D GE sequences have CSF, fat and muscle with broadly similar image intensity and SNR's and have succeeded in getting all tissues about the same signal. However, in the 2D FSE sequence, image contrast between CSF, muscle and scalp was good and SNR was relatively high, imaging time was relatively short.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.25-30
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• 2000

The conditions for callus formation and plant regeneration were confirmed in Italian ryegrass (Lolium mulfiorum Lam.). Among SH (Schenk and Hildebrandt), MS (Murashige and Skoog) and N6 medium (Chu) MS medium was highest degree of efficiencies respectively in callus formation and plant regeneration. In this study, we determined volume of hormones and other compounds appended in media. For callus formation, only $5\;mg/\;{\ell}$ of 2,4-D (2,4-dichlorophenoxy acetic acid) was appended in their media. For plant regeneration, we used MS medium containing $1.0\;mg/\;{\ell}$ of BA and $0.1\;mg/\;{\ell}$ of NAA.

• Korean Journal of Plant Resources
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• v.20 no.4
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• pp.367-374
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• 2007

This study was carried out to establish the micropropagation system of Bupleurum latissimum Nakai that is a Korean native endangered species. Callus were induced from the leaf, petiole and floral bud and the percentage of callus formation was highest in the floral bud on the MS medium containing 2.0 mg ${\cdot}$ $L^{-1}$ 2,4-D. Especially, callus induced from floral bud was formed 77.8% and the percentage of shoot formation was 42.6% on the MS medium containing 2.0 mg ${\cdot}$ $L^{-1}$ 2,4-D plus 1.0 mg ${\cdot}$ $L^{-1}$ TDZ. For simultaneously callus formation and shoot regeneration, 1/2 MS medium was more effective than MS medium. The percentage callus formation, shoot regeneration and rooting were 46.3%, 13.0%, 13.0% in 1/2 MS medium, respectively. Soot regeneration from callus was good in 1/2 MS medium supplemented with 2.0 mg ${\cdot}$ $L^{-1}$ 2,4-D plus 1.0 mg ${\cdot}$ $L^{-1}$ BA where percentage of shoot regeneration was 74.1 %, and the number of shoot per explant was 2.4. The percentage of rooting was lowest (57.8%) in control while it was highest (97.8%) in 1.5 mg ${\cdot}$ $L^{-1}$ NAA. In acclimatization of regenerated plantlets, the percentage of survived plantlets was highest (86.1%), and plant height, root length and fresh weight were good in the soil for horticulture.

• Korean Journal of Audiology
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• v.24 no.3
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• pp.119-126
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• 2020

Background and Objectives: In distracting listening conditions, individuals need to pay extra attention to selectively listen to the target sounds. To investigate the amount of listening effort required in reverberating and noisy backgrounds, a semantic mismatch was examined. Subjects and Methods: Electroencephalography was performed in 18 voluntary healthy participants using a 64-channel system to obtain N400 latencies. They were asked to listen to sounds and see letters in 2 reverberated×2 noisy paradigms (i.e., Q-0 ms, Q-2000 ms, 3 dB-0 ms, and 3 dB-2000 ms). With auditory-visual pairings, the participants were required to answer whether the auditory primes and letter targets did or did not match. Results: Q-0 ms revealed the shortest N400 latency, whereas the latency was significantly increased at 3 dB-2000 ms. Further, Q-2000 ms showed approximately a 47 ms delayed latency compared to 3 dB-0 ms. Interestingly, the presence of reverberation significantly increased N400 latencies. Under the distracting conditions, both noise and reverberation involved stronger frontal activation. Conclusions: The current distracting listening conditions could interrupt the semantic mismatch processing in the brain. The presence of reverberation, specifically a 2000 ms delay, necessitates additional mental effort, as evidenced in the delayed N400 latency and the involvement of the frontal sources in this study.

• Journal of Audiology & Otology
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• v.24 no.3
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• pp.119-126
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• 2020

Background and Objectives: In distracting listening conditions, individuals need to pay extra attention to selectively listen to the target sounds. To investigate the amount of listening effort required in reverberating and noisy backgrounds, a semantic mismatch was examined. Subjects and Methods: Electroencephalography was performed in 18 voluntary healthy participants using a 64-channel system to obtain N400 latencies. They were asked to listen to sounds and see letters in 2 reverberated×2 noisy paradigms (i.e., Q-0 ms, Q-2000 ms, 3 dB-0 ms, and 3 dB-2000 ms). With auditory-visual pairings, the participants were required to answer whether the auditory primes and letter targets did or did not match. Results: Q-0 ms revealed the shortest N400 latency, whereas the latency was significantly increased at 3 dB-2000 ms. Further, Q-2000 ms showed approximately a 47 ms delayed latency compared to 3 dB-0 ms. Interestingly, the presence of reverberation significantly increased N400 latencies. Under the distracting conditions, both noise and reverberation involved stronger frontal activation. Conclusions: The current distracting listening conditions could interrupt the semantic mismatch processing in the brain. The presence of reverberation, specifically a 2000 ms delay, necessitates additional mental effort, as evidenced in the delayed N400 latency and the involvement of the frontal sources in this study.

• Journal of IKEEE
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• v.12 no.2
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• pp.124-130
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• 2008

Vector Graphics describes an image with mathematical statements instead of pixel information. Which enables easy scalability without loss in image quality and usually results in a much smaller file size compared with bitmap images. In this paper, we propose Vector Graphics Accelerator for mobile device with scan-line edge flag algorithm to render vector image without sorting process of edge. Proposed Vector Graphics Accelerator was verified with OpenVG 2D Vector image. The estimated processing time of proposed Accelerator with Tiger image is 12ms on Tessellation process, and total rendering time is 208ms. Estimated rendering performance with Tiger image is about 5 frame per second

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.289-291
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• 1999

Hypocotyl explants from 7 days old seedlings of one $F_1$ hybrid cultivar and two pure lines of cucumber formed embryogenic calli at frequencies of up to 8% when cultured on Murashige and Skoog medium (MS) supplemented with 1 mg/L 2,4-D for 3 weeks. Embryogenic calli gave rise to somatic embryos. When slices of somatic embryos were cultured on the same medium for 4 weeks, they formed embryogenic calli. Embryogenic cell suspension cultures were established with embryogenic calli in MS liquid medium with 1 mg/L 2,4-D. Embryogenic potential of cell suspension cultures was maintained by subculturing every seven days. When the level of 2,4-D in the medium was lowered to 0.2 mg/L by diluting with liquid MS basal medium, embryogenic cell suspension cultures underwent development into numerous somatic embryos. When plated onto MS basal medium, over 95% of somatic embryos developed into plantlets. Plantlets were transplanted to potting soil and grown to maturity.