• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.213-231
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• 1987

For callus culture of leaves and internodal tissue of Quercus acutissirna Carr. and Quercus variabitisBL, MS and GD media were supplemented with combinations of different levels of growth substances such as NAA and BAP, NAA and kinetin, 2,4-D and BAP, and 2,4-D and kinetin. The results were obtained as follows; 1. The rates of formation and growth of callus were good on the GD medium supplemented with NAA and BAP, but the values were quite variable on the MS medium. Root formation occurred at the ratio of 1 : 10-100 in the concentrations of BAP and NAA. 2. The GD medium supplemented with the combination of NAA and kinetin showed 100% callus formation. The callus grew well on the other medium except for that with low concentration of NAA and kinetin. Most of roots were developed from leaf tissue cultured on GD media. 3. The GD medium supplemented with the combination of 2,4-D and BAP also showed 100% callus formation, and growth of callus was good on both of MS and GD media. In particular, the callus derived from internodal tissue showed. the most vigorous growth and reached above 22mm diameter, when they were cultured on MS media supplemented wi th the combinations of $10{\mu}M$ 2,4-D and $1.0{\mu}M$ BAP, and $10{\mu}M$ 2,4-D and $0.1{\mu}M$ BAP. 4. The GD medium supplemented with the combination of 2,4-D and kinetin showed high rate of callus formation, as compared with MS medium Callus grew well on both of MS and GD media.

• The Journal of the Korea Contents Association
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• v.8 no.11
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• pp.210-216
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• 2008

In this study, image comparisons were carried out using a MRI contrast medium which was derived by mixing a polyaminocarboxylic ligand and a gadolinium (III) transition metal which is paramagnetic and has good neutron absorbing capabilities with Gd-DTPA which is currently being used widely in the clinical setting. By using a 1.0T (Harmony, SIEMENS) MR equipment, phantoms of which 100cc of saline was diluted with a diethylenetriaminetriacetic acid derivative and Gd-DTPA were imaged. The amount of diethylenetriaminetriacetic acid and Gd-DTPA which was diluted into the 100cc of saline was 0.05mmol/L, 0.1mmol/L, 0.15mmol/L, 0.2mmol/L, 0.3mmol/L, 0.5mmol/L, 1.0mmol/L, 2.0mmol/L, 3.0mmol/L and 4.9mmol/L respectively. Head coils were used and while fixing the SE pulse sequence and image variable (as TE is 14ms, 1NEX with a 256x201 matrix), the signal intensity and simple contrast ratios according to changing concentrations and TR were compared with various TR at 300ms, 400ms, 500ms, 600ms, 700ms, 800ms, 900ms, 1000ms, 1200ms, 1400ms and 1600ms. According to the comparison results of the signal intensity of the image based on changes in contrast medium concentrations and TR, the differences in signal intensity between the two contrast mediums were found to be small at $1.0{\sim}2.0mmol/L$ when the highest signal intensity was achieved. However, at concentrations of 1.0mmol/L or less, the signal intensity was markedly higher in the Diethylenetriaminetriacetic acid derivative than in the Gd-DTPA complex. It was also found that the differences in the signal intensities demonstrated by the concentrations of the contrast mediums were affected by the TR. Accordingly, the efficacy of the Diethylenetriaminetriacetic acid derivative was shown to be better than the Gd-DTPA and also possible to get the optimum image quality by the use of an appropriate TR with appropriate concentrations of contrast medium.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.1991-1995
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• 2005

Sensitivity factors of elements by a glow discharge mass spectrometry (GD-MS) were intensively investigated and compared with a laser ablation inductively coupled plasma-mass spectrometry (ICP-MS). In case of copper matrix, the sensitivity factor by GD-MS generally decreases with the increase of the mass number of element. The details are a little different between each data measured by Faraday and multiplier detectors. The factor by a multiplier detector drastically decreases with the mass increase in the region of low mass as in Faraday detector’s case, but slowly in the high mass region. On the contrast, the sensitivity factor of solution standard by a conventional ICP-MS slowly increases with the increase of elemental mass number even though there are some exceptions such as gold and also the sensitivity factor by a laser ablation ICP MS generally increases with mass number of element in the specimen of glass type. In case of steel matrix, any definite trends could not be shown in the relationship between the GD-MS’s sensitivity factor and elemental mass.

• Journal of Magnetics
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• v.21 no.3
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• pp.303-307
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• 2016

$Y_{3-x}R_xFe_5O_{12}$ (R = La, Nd, and Gd) powder were fabricated using a sol-gel pyrolysis method. Their magnetic properties and crystalline structures were investigated using x-ray diffraction (XRD), a vibrating sample magnetometer (VSM), and $M{\ddot{o}}ssbauer$ Spectrometer. The $M{\ddot{o}}ssbauer$ spectra for the powders were taken at various temperatures ranging from 12 K to Curie temperature (Tc). The isomer shifts indicated that the valence states of Fe ions for the 16(a) and 24(d) sites have a ferric character. The saturation magnetization (Ms) increases from 32 to 34 (emu/g) for the YIG, and Nd-YIG, respectively. However, Ms decreases to 27 (emu/g) at Gd-YIG.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3665-3670
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• 2012

Metal-p-$NH_2$-Bn-DOTA (paraammionobenzyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid: ABDOTA) complex was synthesized and purified for bio-tagging to quantify biological target materials using laser ablation (LA)-ICP-MS. Since the preparation of a pure and stable tagging complex is the key procedure for quantification, magnetic particles were used to purify the synthesized metal-ABDOTA complex. The magnetic particles immobilized with the complex attracted to a permanent magnet, resulting in fast separation from free un-reacted metal ions in solution. Gd ions formed the metal-complex with a higher yield of 64.3% (${\pm}3.9%$ relative standard deviation (RSD)) than Y ions, 52.3% (${\pm}2.5%$ RSD), in the pH range 4-7. The complex bound to the magnetic particles was released by treatment with a strong base, of which the recovery was 81.7%. As a reference, a solid phase extraction (SPE) column packed with Chelex-100 resin was employed for separation under similar conditions and produced comparable results. The tagging technique complemented polydimethylsiloxane (PDMS) microarray chip sampling in LA-ICP-MS, allowing determination of small sample volumes at high throughputs. For application, immunoglobulin G (IgG) was immobilized on the pillars of PDMS microarray chips and then tagged with the prepared Gd complex. IgG could then be determined through measurement of Gd by LA-ICP-MS. A detection limit of 1.61 ng/mL (${\pm}0.75%$ RSD) for Gd was obtained.

• Korean Journal of Plant Resources
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• v.6 no.2
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• pp.171-179
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• 1993

This study was conducted to investigate the effect of growth regulators and medium composition on the growth of each stage in apical meristem culture for mass propagation of Zanthoxylum piperitum var. inerme Makino. The source material, shoot tip segments were taken from three-years old graft trees. Apical meristems were cultured in vitro on basal MS, GD, WS, half strength MS(1/2MS) and half strength GD(1/2GD) media supplemented with various concentrations for growth regulators(BA, IBA) and inorganic nutrients. The results summarized are as follows: 1. In culture establishment stage, ratio of culture establishment was 96.7% and the best resuit was obtained using MS medium supplemented with 1.0mg/l BA and 0.2mg/l IBA. 2. In shoot multitication stage, both shoot multiplication and growth were achieved in average 5.6cm. These results were obtained on in MS medium supplemented with 1.0mg/l BA and 0.2mg/l IBA. 3. In roothing stage, phloroglucinol(PG) acted as IBA synergist in root initiation. The most faverable combinations for root development was half-strength MS medium supplemented with 162mg/l PG and 0.2mg/l IBA, and ratio of rooting was 58.0%. 4. In Vitro formed plantlets were transplanted to paper pots in greenhouse with 85% of relative humidity. 96% of survival rate was obtained from artificial soil mix having same volume of sand, vermiculite, peat, and soil.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.752-756
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• 2002

Green-emitting $Zn_2SiO_4:Mn$ phosphors for PDP(Plasma Display Panel) application were synthesized by colloidal seed-assisted spray pyrolysis process. The codoping with $Gd^{3+}/Li^+$, which replaces $Si^{4+}$ site in the willemite structure, was performed to improve the luminous properties of the $Zn_2SiO_4:Mn$ phosphors. The particles prepared by spray pyrolysis process using fumed silica colloidal solution had a spherical shape, small particle size, narrow size distribution, and non-aggregation characteristics. The $Gd^{3+}/Li^+$ codoping amount affected the luminous characteristics of $Zn_2SiO_4:Mn$ phosphors. The codoping with proper amounts of $Gd^{3+}/Li^+$ improved both the photoluminescence efficiency and decay time of $Zn_2SiO_4:Mn$ phosphor particles. In spray pyrolysis, the post-treatment temperature is another factor controlling the luminous performance of $Zn_2SiO_4:Mn$ phosphors. The $Zn_{1.9}SiO_4:Mn_{0.1}$ phosphor particles containing 0.1 mol% $Gd^{3+}/Li^+$ co-dopant had a 5% higher PL intensity than the commercial product and 5.7 ms decay time after post-treatment at $1,145^{\circ}C$.

• Korean Journal of Materials Research
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• v.5 no.8
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• pp.1040-1044
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• 1995

Magnetic garnet films of (YSmLuCa)$_3$(FeGe)$\_$5/O$\_$12/ have been grown by the liquid phase eqitaxy method on the substrate of non-magnetic garnet Gd$_3$Ga$\_$5/O$\_$12/. The variation of Sm ion concentration were varied 0.3, 0.4, 0.6, mole/formula unit respectively. The magnetic properties of the samples for the bubble magnetic materials, such as, line width ΔH of ferromagnetic resonance (FMR), magnetic saturation induction 4$\pi$Ms, wall mobility u$\_$w/ uniaxial magnetic anisotropy energy Ku, were measured and discussed the relations between these properties. The line width ΔH decreases with increasing 4$\pi$Ms, and with decreasing Sm concentration. The anisotropy energy Ku increases not only with increasing Sm ion concentration, but also increasing 4$\pi$Ms. The value of wall mobility u$\_$w/ increase with increasing 4$\pi$Ms and decreases with increasing Sm concentration. We define a physical constant Eι from the fact that the product of 4$\pi$Ms and ΔH is constant with dimension of energy density. The Eι is dependent only on Sm concentration.density. The Eι is dependent only on Sm concentration.

• Toxicological Research
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• v.29 no.1
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• pp.53-60
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• 2013

Studies on milk transfer of drugs in non-human primates (NHPs) are among the crucial components in the assessment of peri- and postnatal toxicity because of the similarity between NHPs and humans. To evaluate the milk transfer of valproic acid (VPA) in NHPs, the toxicokinetics of VPA, an antiepileptic drug, were studied in pregnant cynomolgus monkeys. VPA was administered once daily to pregnant cynomolgus monkeys at doses of 0, 30, 90, and 270 mg/kg by oral gavage from Day 100 of gestation (GD 100) to Day 31 of lactation (LD 31). Concentrations of VPA and its metabolite, 4-ene-VPA, in the maternal plasma on GD 100, GD 140, and LD 30, and concentrations of VPA and 4-ene-VPA in the offspring plasma and milk on LDs 30 and 31, respectively, were quantified using liquid chromatography tandem mass spectrometry (LC/MS/MS). After administration of a single oral dose of VPA to pregnant monkeys on GD 100, the concentrations of VPA and 4-ene-VPA were generally quantifiable in the plasma of all treatment groups up to 24 hr after administration, which showed that VPA was absorbed and that the monkeys were systemically exposed to VPA and 4-ene-VPA. After administration of multiple doses of VPA to the monkeys, VPA was detected in the pup's plasma and in milk taken on LD 30 and LD 31, respectively, which showed that VPA was transferred via milk, and the pup was exposed to VPA. Further, the concentration of VPA in the milk increased with an increase in the dose. Extremely low concentrations of 4-ene VPA were detected in the milk and in the pup plasma. In conclusion, pregnant monkeys were exposed to VPA and 4-ene-VPA after oral administration of VPA at doses of 30, 90, and 270 mg/kg/day from GD 100 to LD 31. VPA was transferred via milk, and the VPA exposure to the pup increased with an increase in the dose of VPA. The metabolite, 4-ene VPA, was present in extremely low concentrations (< 0.5 ${\mu}g/ml$) in the milk and in the pup plasma. In this study, we established methods to confirm milk transfer in NHPs, such as mating and diagnosis of pregnancy by examining gestational sac with ultrasonography, collection of milk and pup plasma and determination of toxicokinetics, using cynomolgus monkeys.

• Analytical Science and Technology
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• v.5 no.2
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• pp.169-176
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• 1992

Analytical detection limits and Relative Ion Yield (RIY) by a jet type ion source glow discharge mass spectrometer(GD/MS) have been measured. With a jet type ion source, the sample loss rate for a Cu sample is 0.23 mg/min with 0.1 L/min gas flow rate and 0.11 mg/min with no gas flow rate. However, the ion intensity of Cu does not change significantly with thee variation of the gas flow rate. The RIY values obtained from the calibration curves of the six copper based standards were between 0.57 of Fe and 3.5 of Cr. The detection limits of most elements were in the range of 0.9 and 2.0 ppm when the glow discharge was operated at 4 mA, 1000V.