• The Plant Pathology Journal
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• v.22 no.2
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• pp.139-146
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• 2006

The 3' region of Potato virus X (PVX) has the 74 nt 3'-nontranslated region (NTR) that is conserved among all potexviruses and contains several cis-acting elements for minus-strand and plus-strand RNA accumulation. Three stem-loop structures (SL1-SL3), especially formation of SL3 and U-rich sequence of SL2, and near upstream elements in the 3' NTR were previously demonstrated as important cis-acting elements. To Investigate the binding of these cis-acting elements within 3' end with host protein, we used the electrophoretic mobility shift assays (EMSA) and UV-cross linking analysis. The EMSA with cellular extracts from tobacco and RNA transcripts corresponding to the 150 nt of the 3' end of PVX RNA showed that the 3' end of PVX formed complexes with cellular proteins. The specificity of protein binding was confirmed through competition assay by using with 50-fold excess of specific and non-specific probes. We also conducted EMSA with RNAs containing various mutants on those cis-acting elements (${\Delta}10$10, SL3B, SL2A and ${\Delta}21$; J Mol Biol 326, 701-720) required for efficient PVX RNA accumulation. These analyses supported that these cis-acting elements are required for interaction with host protein(s). UV-cross linking analysis revealed that at least three major host proteins of about 28, 32, and 42 kDa in mass bound to these cis-elements. These results indicate that cis-acting elements from 3' end which are important for minus and plus-strand RNA accumulation are also required for host protein binding.

• Korean Journal of Veterinary Service
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• v.28 no.3
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• pp.203-213
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• 2005

Oxytetracycline, tetracycline, chlortetracycline and doxycycline in honey were separated by solid phase extraction (SPE) and determined with high performance liquid chromatography (HPLC) with UV/Visible detector. Analysis was carried out using following conditions: XTerra $C_8$ column $(3.9\times150mm\;i.d. 5{\mu}m)$, mobile phase composed of 0.01M oxalic acid : methanol : acetonitrile (820 : 80 : 100, v/v/v), isocratic pump at a flow rate of 0.9 ml/min. and $50{\mu}l$ of injection volume, UV/Visible detector with wavelength of 360nm. The calibration curves of four tetracyclines showed linearity $(\gamma^2>0.999)$ at concentration range of $100\~1,000 ng/ml$. The recoveries in fortified honey represented more than $70\%$ with low coefficient of variation $(<10\%)$ for concentration range of four tetracyclines. The detection limits for oxytetracycline, tetracycline, chlortetracycline and doxycycline were 13.8, 14.6, 26.2 and 24.9ng/g in acacia honey. respectively. We also monitored tetracyclines residue in domestic honey [n : 38, acacia (20), wild flower (18) ] and foreign honey [n=22, legally distributed (13), illegally distributed (9)] using modified Charm II screening and HPLC confirmation methods. Seven of the 60 samples $(11.7\%)$ were suspect positive using modified Charm II screening test. Chlortetracycline residue was found in one foreign honey (illegally distributed) tested at concentrations of 0.22 ppm. Conclusively, for more effective control of tetracyclines used in beekeeping should be further survey for residues in honey and also national guidelines (maximum residue limit : MRL) and methods should be obligatory.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.145-150
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• 2005

To dispose of radwaste in a repository, the safety of disposal must be ensured. This study developed a program for estimating radionuclide accumulation of radwaste, based on the material balance method, one of the indirect methods, and performed application evaluation during the 9th preventive maintenance period of Gori Plant 4, one of the commercial power plants in Korea. First of all, to ensure the technique developed in this study is assessed accurately, this study utilized the data regarding the radionuclide removal in the purification system during the shutdown water chemistry control, and a related estimation technique called SCALP. The target nuclide was Co-60, and it turned out that the relative error was less than $1\%$. The estimation result was compared with the result of direct measurement of the radwaste during the corresponding period as presented by commercial power plants. The result showed that the quantity of Co-60 measured by the direct method was about $50\%$ less than that calculated by the technique developed in this study.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3707-3711
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• 2011

Silver nanoparticles coated with silica can be obtained by the reduction of $AgNO_3$ with hydrazine in the presence of NaOH-stabilized, active silicic acid (polysilicic acid). The size of the silver nanoparticles and the silica shell thicknesses were affected by varying the hydrazine content, the active silicic acid content and the experimental method (e.g. hydrothermal method). Typically, silver nanoparticles sized around 40 nm were aggregated, connected by silica. The presence of peaks centered around 400 nm in UV-vis spectra corresponds to the surface plasmon resonance of silver nanoparticles. The size of the aggregated silver nanoparticles increased with increasing hydrazine concentration. Under hydrothermal conditions at $150^{\circ}C$ the formation of individual silica particles was observed and the sizes of the silver nanoparticles were reduced. The hydrothermal treatment of silver nanoparticles at $180^{\circ}C$ gives a well-defined Ag@$SiO_2$ core-shell in aggregated silica sol particles. The absorption band observed at around 412 nm were red-shifted with respect to the uncoated silver nanoparticles (${\lambda}_{max}$ = 399 nm) due to the larger refractive index of silica compared to that of water. The formation of silver nanoparticles coated with silica is confirmed by UV-visible absorption spectra, transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS) data.

• Analytical Science and Technology
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• v.36 no.1
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• pp.32-43
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• 2023

This study reports for the first time about a stability indicating RP-HPLC method for qualitative and quantitative determination of acalabrutinib in bulk and dosage form and in presence its impurities 1, 2 and 3. The chromatographic separation was carried on Zorbax XDB-C18 (250×4.6 mm; 5 µ id) as stationary phase, Phosphate buffer pH 6.4 and methanol 80:20 (v/v) as mobile phase at a flow rate of 1.0 mL/min, UV detection was carried at wavelength of 238 nm and the analysis was completed with a run time of 15 min. In these conditions the retention time of acalabrutinib and its impurities 1, 2 and 3 was observed to be 3.50, 4.83, 8.40 and 9.93 min respectively. The method was validated for system suitability, range of analysis, precision, specificity, stability and robustness. Spiked recovery at 50 %, 100 % and 150 % was carried for both standard and impurities and the acceptable % recovery of 98-102 was observed for acalabrutinib and both impurities studied and the % RSD in each spiked level was found to be less than 2. Stability tests were done through exposure of the analyte solution to five different stress conditions i.e expose to 1N hydrochloric acid, 1 N sodium hydroxide, 3 % peroxide, 80 ℃ temperature and UV radiation at 254 nm. In all the degradation condition, standard drug acalabrutinib was detected along with both the impurities studied and the degradation products were successfully separated. In the formulation analysis there is no other chromatographic detection of other impurities and formulation excipients. Hence the developed method was found to be suitable for the quantification of acalabrutinib and can separate and analyse impurities 1 and 2.

• Journal of Pharmaceutical Investigation
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• v.34 no.1
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• pp.43-48
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• 2004

The purpose of the present study was to evaluate the bioequivalence of two nizatidine capsules, Axid (Lilly Korea Pharm. Co., Ltd.) and Nex (Bi-nex Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The nizatidine release from the two nizatidine capsules in vitro was tested using KP Apparatus method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solutions and water). The dissolution prefers of two nizatidine capsules were very similar at all dissolution media. Twenty four normal male volunteers were divided into two groups with a randomized 22 crossover study. After two capsules (300 mg nizatidine) were orally administrated, blood was taken and the concentrations of nizatidine in serum were determined using HPLC with UV detector. The pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were determined. The result showed that the differences in $AUC_t$, $C_{max}$ and $T_{max}$ between two nizatidine capsules based on the Axid were -6.16%, -8.26% and -1.82%, respectively. There were no sequence effects between two capsules in these parameter. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(125)(e.g., $log(0.91){\sim}log(0.97)$ and $log(0.85) {\sim}log(0.99)$ for $AUC_t$ and $C_{max}$ respectively), indicting that Nex capsule is bioequivalent to Axid capsule.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.64-67
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• 2006

RF 스퍼터링법을 이용하여 AZO(Al 2wt%, ZnO 98wt%)박막을 glass위에 증착한 후 증착 시간과 증착 압력에 따른 면저항, roughness 및 광투과도를 조사하였다. 본 연구에서 AZO박막의 면 저항은 4-point probe(Guardian, 402S)으로 측정하였으며 광투과도는 IR-VIS-UV spectrophotometer로 측정하였다. AZO 박막을 20분 증착하는 동안, 아르곤 flow양이 50, 100, 150sccm일 때 면저항은 $20\;{\Omega}/{\square}$이고, 200sccm일 때 $3744\;{\Omega}/{\square}$였다. AZO 박막의 두께를 일정하게 증착하는 동안, 아르곤 flow양이 50sccm일 때 면저항은 $49.6\;{\Omega}/{\square}$이고 100, 150, 200sccm일 때 $38{\Omega}/{\square}$였으며, 광투과도는 모두 80%이상을 보였다. Roughness는 각각 4.1nm, 7.6nm, 5.2nm, 16.9nm였다.

• Korean Journal of Materials Research
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• v.23 no.8
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• pp.469-475
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• 2013

Al-doped ZnO(AZO) thin films were synthesized using atomid layer deposition(ALD), which acurately controlled the uniform film thickness of the AZO thin films. To investigate the electrical and optical properites of the AZO thin films, AZO films using ALD was controlled to be three different thicknesses (50 nm, 100 nm, and 150 nm). The structural, chemical, electrical, and optical properties of the AZO thin films were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy, field-emssion scanning electron microscopy, atomic force microscopy, Hall measurement system, and UV-Vis spectrophotometry. As the thickness of the AZO thin films increased, the crystallinity of the AZO thin films gradually increased, and the surface morphology of the AZO thin films were transformed from a porous structure to a dense structure. The average surface roughnesses of the samples using atomic force microscopy were ~3.01 nm, ~2.89 nm, and ~2.44 nm, respectively. As the thickness of the AZO filmsincreased, the surface roughness decreased gradually. These results affect the electrical and optical properties of AZO thin films. Therefore, the thickest AZO thin films with 150 nm exhibited excellent resistivity (${\sim}7.00{\times}10^{-4}{\Omega}{\cdot}cm$), high transmittance (~83.2 %), and the best FOM ($5.71{\times}10^{-3}{\Omega}^{-1}$). AZO thin films fabricated using ALD may be used as a promising cadidate of TCO materials for optoelectronic applications.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.1
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• pp.21-28
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• 2004

We have demonstrated the applicability of dry film photoresist (DFR) in photolithography process for fine pitch solder bumping on the polytetrafluoroethylene (PTFE/Teflon ) printed circuit board (PCB). The copper lines were formed with 100$\mu\textrm{m}$ width and 18$\mu\textrm{m}$ thickness on the PTFE test board, and varying the gaps between two copper lines in a range of 100-200$\mu\textrm{m}$. The DFRs of 15$\mu\textrm{m}$ thickness were laminated by hot roll laminator, by varying laminating temperature from $100{\circ}C$ to 15$0^{\circ}C$ and laminating speed from 0.28-0.98cm/s. We have found the optimum process of DFR lamination on PTFE PCB and accomplished the formation of indium solder bumps. The optimum lamination condition was temperature of $150^{\circ}C$ and speed of about 0.63cm/s. And the smallest size of indium solder bump was diameter of 50$\mu\textrm{m}$ with pitch of 100$\mu\textrm{m}$.

• Journal of the Korean institute of surface engineering
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• v.51 no.2
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• pp.126-132
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• 2018

SnS thin films with different substrate temperatures ($150 {\sim}300^{\circ}C$) as process parameters were grown on soda-lime glass substrates by RF magnetron sputtering. The effects of substrate temperature on the structural and optical properties of SnS thin films were investigated by X-ray diffraction (XRD), Raman spectroscopy (Raman), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and Ultraviolet-visible-near infrared spectrophotometer (UV-Vis-NIR). All of the SnS thin films prepared at various substrate temperatures were polycrystalline orthorhombic structures with (111) planes preferentially oriented. The diffraction intensity of the (111) plane and the crystallite size were improved with increasing substrate temperature. The three major peaks (189, 222, $289cm^{-1}$) identified in Raman were exactly the same as the Raman spectra of monocrystalline SnS. From the XRD and Raman results, it was confirmed that all of the SnS thin films were formed into a single SnS phase without impurity phases such as $SnS_2$ and $Sn_2S_3$. In the optical transmittance spectrum, the critical wavelength of the absorption edge shifted to the long wavelength region as the substrate temperature increased. The optical bandgap was 1.67 eV at the substrate temperature of $150^{\circ}C$, 1.57 eV at $200^{\circ}C$, 1.50 eV at $250^{\circ}C$, and 1.44 eV at $300^{\circ}C$.