• Korean Journal of Microbiology
• /
• v.20 no.1
• /
• pp.1-10
• /
• 1982

From Aspergillus nidulans, six suppressor mutants, MSI-MS6, were isolated, and their characteristics were analysed. These were the suppressor mutants for acriflavin resistant and nicotinamide auxotrophic mutant phenotypes. MS1, MS2, MS5 and MS6, were linked to the chromosome IV, I, II respectively, and MS2 was linked to one of the rest chromosomes, MS3 and MS6 mutants had both suppressors for acriflavin resistant marker and for nicotinamide auxotrophic marker. In order to know the stability and efficiency of the suppressors, their reversion frequencies, that is, frequencies of losing the suppressibility, were analysed. Only MS3 and MS5 were reversed with high frequency. The four mutants didn't lose their suppressibilities, and this meant that the suppressors of these four were very stable and highly effcient. The suppressor specificities of these mutants were tested for other mutant's phenotype marker. One of the six suppressors, MS1, had the suppressor specificity for acriflavin resistant marker of 163 strain.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.4
• /
• pp.678-683
• /
• 2003

This study presents a result of performance with the design of network topology for voice and data integration under computer network. This network is consisted of FastEthernet, other LANs and ATM WAN(wide area network), and performance evaluation of delay in a PBX+IP network, delay in a VoIP network and delay in a IP+ATM network will be shown. We use parameters including network bandwidth, number of packet, routing protocol(IGRP, OSPF). We simulate integrated of voice and data used PBX. we will study further about the case of integrated of voice and data environments using PBX. and, evaluate IP+ATM WAN average measured network delay and average delay of VoIP network.

• Analytical Science and Technology
• /
• v.25 no.6
• /
• pp.435-440
• /
• 2012

A liquid chromatography-electrospray ionization-tandem mass spectrometry method (LC-ESI-MS/MS) was used for determining perchlorate in the Gum-River surface water. Sample was directly injected into LC-ESI-MS/MS after the filtrations using PTFE filter paper. The coefficient of variation of perchlorate was less than 3% and the limit of quantification was 0.17 ${\mu}g/L$. Water samples were collected from thirty-five basins of Gum-River on February, April and June 2012, respectively. As a result, perchlorate was detected in the concentration range of 0.23-3.73 ${\mu}g/L$ (mean 0.20 ${\mu}g/L$) in the frequency of 15% in general surface water and in the concentration range of 0.36-25.10 ${\mu}g/L$ (mean 1.69 ${\mu}g/L$) in the frequency of 36% in surface water samples near industry area.

• Journal of the Korean Society of Radiology
• /
• v.5 no.6
• /
• pp.401-407
• /
• 2011

The purpose of this study is to know the differences of MR spectra, obtained from normal volunteers by variable TE value, through the quantitative analysis of brain metabolites by peak integral and SNR between 1.5T and 3.0T, together with PRESS and STEAM pulse sequence. Single-voxel MR proton spectra of the human brain obtained from normal volunteers at both 3.0T MR system (Magnetom Trio, SIEMENS, Germany) and 1.5T MR system (Signa Twinspeed, GE, USA) using the STEAM and PRESS pulse sequence. 10 healthy volunteers (3.0T:3 males, 2 females; 1.5T : 3 males, 2 females) with the range from 22 to 30 years old (mean 26 years) participated in our study. They had no personal or familial history of neurological diseases and had a normal neurological examination. Data acquisition parameters were closely matched between the two field strengths. Spectra were recorded in the white matter of the occipital lobe. Spectra were compared in terms of resolution and signal-to-noise ratio(SNR), and echo time(TE) were estimated at both field strengths. Imaging parameters was used for acquisition of the proton spectrum were as follow : TR 2000msec, TE 30ms, 40ms, 50ms, 60ms, 90ms, 144ms, 288ms, NA=96, VOI=$20{\times}20{\times}20mm3$. As the echo times were increased, the spectra obtained from 3.0T and 1.5T show decreased peak integral and SNR at both pulse sequence. PRESS pulse sequence shows higher SNR and signal intensity than those of STEAM. Especially, Spectra in normal volunteers at 3.0T demonstrated significantly improved overall SNR and spectral resolution compared to 1.5T(Fig1). The spectra acquired at short echo time, 3T MR system shows a twice improvement in SNR compared to 1.5T MR system(Table. 1). But, there was no significant difference between 3.0Tand 1.5T at long TE It is concluded that PRESS and short TE is useful for quantification of the brain metabolites at 3.0T MRS, our standardized protocol for quantification of the brain metabolites at 3.0T MRS is useful to evaluate the brain diseases by monitoring the systematic changes of biochemical metabolites concentration in vivo.

• Mass Spectrometry Letters
• /
• v.14 no.4
• /
• pp.153-159
• /
• 2023

The copper ion, Cu(II), binding sites for amyloid fragment Aβ1-16 (=Aβ16 ) were investigated to explain the biological activity difference in the Aβ16 aggregation process. The [M+Cu+(z-2)H]^z+ (z = 2, 3 and 4, M = Aβ16 monomer) and [D+Cu+(z-2)H]^z+ (z = 3 and 5, D = Aβ16 dimer) structures were investigated using electrospray ionization (ESI) mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Fragment ions of the [M+Cu+(z-2)H]^z+ and [D+Cu+(z-2)H]^z+ complexes were observed using collision-induced dissociation MS/MS. Three different fragmentation patterns (fragment "a", "b", and "y" ion series) were observed in the MS/MS spectrum of the (Aβ16 monomer or dimer-Cu) complex, with the "b" and "y" ion series regularly observed. The "a" ion series was not observed in the MS/MS spectrum of the [M+Cu+2H]⁴⁺ complex. In the non-covalent bond dissociation process, the [D+Cu+3H]⁵⁺ complex separated into three components ([M+Cu+H]³⁺, M³⁺, and M²⁺), and the [M+Cu]²⁺ subunit was not observed. The {M + fragment ion of [M+Cu+H]³⁺} fragmentation pattern was observed during the covalent bond dissociation of the [D+Cu +3H]⁵⁺ complex. The {M + [M+Cu+H]³⁺} complex geometry was assumed to be stable in the [D+Cu+3H]⁵⁺ complex. The {M + fragment ion of [M+Cu]²⁺} fragmentation pattern was also observed in the MS/MS spectrum of the [D+Cu+H]³⁺ complex. The {M + [y₉+Cu]¹⁺} fragment ion was the characteristic fragment ion. The [D+Cu+H]³⁺ and [D+Cu+3H]⁵⁺ complexes were likely to form a monomer-monomer-Cu (M-M-Cu) structure instead of a monomer-Cu-monomer (M-Cu-M) structure.

• Korean Journal of Pharmacognosy
• /
• v.44 no.4
• /
• pp.350-361
• /
• 2013

Asarum sieboldii has been used for treatment of fever, pain, common cold, and chronic sinusitis in Korea. In this study, we performed quantification analysis of seven major constituents including aristolochic acid I, aristolochic acid II, ${\alpha}$-asarone, ${\beta}$-asarone, elemicin, methyl eugenol, and safrole in the 70% ethanol extract of Asarum sieboldii and its solvent fractions, n-hexane, ethylacetate, n-butanol, and water ones using a ultra-performance liquid chromatography-electrospray ionization-mass spectrometer(UPLC-ESI-MS) and gas chromatography-mass spectrometer(GC-MS). Regression equations of seven components were acquired with $r^2$ values >0.99. The values of limit of detection(LOD) and quantification(LOQ) were 0.1-3.9 ng/mL and 0.3-11.7 mg/mL, respectively. The amount of the seven compounds in Asarum sieboldii were not detected -143.66 mg/g. The established LC-MS/MS and GC-MS methods will be helpful to improve quality control of Asarum sieboldii.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.3
• /
• pp.231-240
• /
• 2023

In this research, our goal was to explore the potential use of cement mortar augmented with liquid red mud. To facilitate this, we neutralized liquid red mud(LR) - exhibiting a pH of 10-12 - using sulfuric acid to yield sulfuric acid neutralized red mud(SR). We then evaluated the flow, setting time, and compressive strength of the cement mortar combined with liquid red mud, while also performing a thorough examination of its chemical properties through X-ray diffraction(XRD) and scanning electron microscopy(SEM). The flow tests indicated a decrease in flow values for both MS-LR and MS-SR in comparison to the Plain. Analogously, the setting time for MS-LR and MS-SR was found to be abbreviated when juxtaposed with the Plain. With regards to compressive strength, MS-LR demonstrated a surge in strength at the 1-day mark, while MS-SR displayed a diminution at the 1-day and 3-day timepoints compared to the Plain. XRD analysis illustrated that after 28 days, the XRD patterns of Plain and MS-SR bore significant resemblance, though a new peak was detected in MS-LR. SEM imagery highlighted that the microstructures of Plain and MS-SR were alike, but MS-LR manifested a distinct microstructure, characterized by a finely fibrous formation. Based on these observations, we infer that the replacement of cement mortar with liquid red mud neutralized with sulfuric acid contributes to a noticeable enhancement in strength, thereby verifying its suitability for this application.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.3
• /
• pp.547-552
• /
• 2004

Streptomyces thermovulgans malate synthase (stMS) is known to be more thermostable and thermoactive than S. coelicolor malate synthase (scMS). Therefore, based on the amino acid sequence of stMS, 3 scMS mutants, namely P186R, T8PL9P, and T8PL9PP186R, were created by site-directed mutagenesis in an attempt to engineer a more thermoactive and thermostable enzyme. An enzymatic analysis of the wild-type and mutant MS revealed that P186R and T8PL9PP186R were more thermoactive than the wild-type scMS and T8PL9P. Furthermore, all 3 mutants exhibited a greater thermo stability than scMS, thereby suggesting that both R186 and P8P9 can cause increased thermo stability in scMS.

• Journal of Acupuncture Research
• /
• v.31 no.3
• /
• pp.57-65
• /
• 2014

Objectives : The aim of this report was to investigate the effects of scalp acupuncture on central post-stroke pain. Methods : We treated a patient with central post-stroke pain from Lt thalamo-geniculate artery territory infarction with scalp acupuncture(MS6 and MS7) and usual treatment of Korean medicine. We evaluated pain severity using numerical rating scale(NRS). The scalp acupuncture was performed once a day for 3 weeks. Results : After 15th treatment of scalp acupuncture, NRS decreased from 8 to 3. Conclusions : This result suggests that scalp acupuncture(MS6 and MS7) is effective in treating central post-stroke pain. We hope that more clinical data and studies are to be done for efficient application.

• Korean Journal of Plant Tissue Culture
• /
• v.26 no.2
• /
• pp.103-107
• /
• 1999

The effects of MS salt strength, sucrose, and cultural conditions on bulblet formation and growth were investigated to optimize the conditions for micropropagating bulblets from in vitro bulb scales of Lilium Oriental Hybrid 'Casa Blanca'. There was no difference on bulblet formation in the range of 1/2~2 $\times$ strength of MS salt, but it was inhibited remarkably in 3 $\times$ strength of MS salt. The growth of regenerated bulblets was most stimulated on MS basal medium. Favorable bulblet formation and its growth from bulb scales were achieved when grown on the media with 1 : 2 or 1 : 3 in the ratio of NH$_4$^+ : NO$_3$^- , as well as on MS basal medium (NH$_4$^+ : NO$_3$^- = about l : 2). Therefore, MS basal medium was very suitable for bulblet formation and growth from bulb scales. Bulblet formation was inhibited but its growth was stimulated with increase sucrose concentration in the medium. The growth of regenerated bulblets was very effective on the media with 9~12% sucrose. Addition of activated charcoal (AC) to the medium inhibited bulblet formation from bulb scales, but enhanced the growth of regenerated bulblets. Especially, the medium containing 1 g/L AC was most effective on the growth of bulblets. No difference was found on bulblet formation and growth from bulb scales under light and dark conditions. In vitro micropropagation of L. Oriental Hybrid 'Casa Blanca' was supposed very reasonable to enhance the growth of the bulblets after forming of bulblets from in vitro bulb scales, and then, subculture the bulb scales from the grown bulblets on MS medium with 9% sucrose and 1 g/L AC.