• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.451-459
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• 1999

During the electromyographic evaluation for the diagnosis of neuropathy, presence for site of lesion could be predicted by a detection of denervation potentials such as fibrillation potentials or positive sharp waves in a group of muscles. Unfortunately, since denervation potentials are distinguished by examiner's experience, it is possible to make mistake identifying endplate spikes as a denervation potential. The aim of the study was to extract parameters to make an algorithm for quantitative distinction between denervation potentials and endplate spikes. It will help to minimize the examiner's bias and to localize the site of lesion thus increase the reliability on EMG diagnosis. There types of signals, endplate spike, fibrillation potential and positive sharp wave were obtained from the EDB(extensor digitorum brevis) muscle using then neuropathic patients. Eight parameters such as duration, area, slope, peak-to-peak amplitude, positive peak negative peak amplitude, ratio of positive to negative peak amplitude, and number of phase were extracted and compared. As a results, peak-to-peak amplitude, positive peak amplitude, ratio of positive to negative peak amplitude showed statistically significant differences between endplate spikes and denervation potentials. It was concluded that those parameters could be used to establish an algorithm which will improve the accuracies in automated quantitative EMG diagnosis.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.1-7
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• 2012

There have been few studies related to ELISA for mackerel. In this study we developed a sandwich ELISA for mackerel in processed foods using rabbit polyclonal antibodies against mackerel parvalbumin, the major allergen of mackerel and heat-stable protein. The parvalbumin was purified by ammonium sulfate precipitation and Sephadex G-50 column chromatography. From the standard ELISA curves, the detection limit of parvalbumin was 3 ng/mL and the detection range of mackerel was 5-5,000 ${mu}g/mL$. We further investigated the cross-reactivity of the antibodies toward mackerel, mackerel pike, salmon, flatfish, armorclad rockfish, cod fish, squid, shrimp, blue crab, and lobster. The antibodies were specific for mackerel only. The mean assay recoveries in cooked cream soup, baby food, sausage, and sauce spiked with 0.01 to 0.3% mackerel were 104, 101, 54, and 0%, respectively. In sample tests of 16 commercial items, the qualitative coincidence ratio of assay result and indication was 75%.

• Atmosphere
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• v.29 no.4
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• pp.501-509
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• 2019

Asian Dust is a meteorological phenomenon that sand particles are raised from the arid and semi-arid regions-Taklamakan Desert, Gobi Desert and Inner Mongolia in China-and transported by westerlies and deposited on the surface. Asian dust results in a negative effect on human health as well as environmental, social and economic aspects. For monitoring of Asian Dust, Korea Meteorological Administration operates 29 stations using a continuous ambient particulate monitor. Kim et al. (2016) developed an automatic quality check (AQC) algorithm for objective and systematic quality check of observed PM₁₀ concentration and evaluated AQC with results of a manual quality check (MQC). The results showed the AQC algorithm could detect abnormal observations efficiently but it also presented a large number of false alarms which result from valid error check. To complement the deficiency of AQC and to develop an AQC system which can be applied in real-time, AQC has been modulated. Based on the analysis of instrument status codes, valid error check process was revised and 6 status codes were further considered as normal. Also, time continuity check and spike check were modified so that posterior data was not referred at inspection time. Two-year observed PM₁₀ concentration data and corresponding MQC results were used to evaluate the modulated AQC compared to the original AQC algorithm. The results showed a false alarm ratio decreased from 0.44 to 0.09 and the accuracy and the probability of detection were conserved well in spite of the exclusion of posterior data at inspection time.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.3
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• pp.118-126
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• 2015

Background and objectives: A deficiency of BH4 (tetrahydrobiopterin) not only causes the classical phenylketonuric phenotype, but also is the source of neurological signs and symptoms due to impaired syntheses of L-Dopa and serotonin. The treatment of BH4 deficiency usually consists of replacement with BH4 and the neurotransmitters. We performed this study to finding out long-term follow-up clinical symptoms and prognosis of BH4 deficiency. Methods: Clinical and biochemical, genetic analysis were done retrospectively from January 1999 to July 2015 in Soonchunhyang University Hospital. Results: In our study, total 207 patients were confirmed to hyperphenylalaninemia. Among them, 10 patients were BH4 deficiency. 9 patients were 6-pyruvoyl-tetrahydropterin (PTPS) deficiency and one patient was dihydropteridine reductase (DHPR) deficiency. The patients who received delayed treatment, most of our patients suffered from severe psychomotor retardation, hypotonia and seizure. c.259C>T mutation was identified most commonly in PTPS gene analysis. A patient with DHPR deficiency had a mental retardation, dystonia, seizure. His seizure semiology was dialeptic feature. His EEG showed generalized spike wave patterns. All patients had treated with tolerate L-Dopa, BH4 and 5-hydroxytryptophan. Most of the early treated patients have a good tolerance for drugs well. But some patients had neurologic symptoms, despite early detection and treatment. Conclusion: BH4 deficiency patients who had delayed treatment tend to have severe psychomotor problem and neurologic deficits.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.879-886
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• 2006

The analytical methods of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) for water sample with extremely low concentration was developed to extract large volume and to improve fast chromatography for clean up. Semi-automated solid phase extraction (SPE) system and column coupling chromatography using elution pump was optimized and applied to each processes of treatment plant. Results of disk type SPE indicated that this system was applicable below 40 L of aqueous sample with a flow rate of 0.08 ~ 0.2 L/min. Average recoveries of SPE using labeled sampling spike of $^{37}Cl$-2,3,7,8-TCDD was 97%. Column coupling method resulted in reduced clean up time, solvent volume, increased average recoveries with constant elution rate. The combined methods were applied to the monitoring of drinking water treatment plant. Limits of detection (LOD) of each process were calculated. For example, LOD of raw and treated water ranged 0.094~0.968 pg/L and 0.028~0.364 pg/L, respectively. Combined methods of extraction and cleanup techniques provided fast analysis of PCDD/Fs with high accuracy and low LODs for water samples.

• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.9-15
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• 1993

In an attempt to quantitate and qualitate residual antibiotics and antibacterial agents in meat simultaneously, we studied a gas chromatography-mass spectrometry(GC/M8) analysis. For a simultaneous analysis of penicillin G, chloramphenicol and thiamphenicol in meat, a simple and rapid clean-up procedure including extraction with 0.01 M EDTA-2Na Mcilvaine buffer (pH 4.0), defatting with n-hexane, and elution with 0.01M-methanolic oxalic acid from Bond Elute $C_{18}$ cartridge, and quantitation by selected ion monitoring (SIM) mode after derivatization was performed. The recoveries (%) of penicillin G, chloramphenicol and thiamphenicol (CV, %) at 1 ppm fortification level were 63.5 (7.6), 76.3 (8.1) and 84.7 (2.0), and the detection limits of those were 0.6, 0.085 and $0.084\;\mu\textrm{g}$ beef, respectively. This method using 81M mode allows excellent detection and quantitation of residual antibiotics and antibacterial agents in meat. Moreover, confirmation by a full scan electron impact mass spectrum is possible if residual level in the sample in above 1 ppm.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.251-259
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• 1996

Two-Photon Fluorescence (TPF) experiment measures temporal width of an amplified short laser pulse which has passed through a four-pass Nd: glass amplifier, after selecting a single pulse from pulse train Q-switched and mode-locked(QSML) in Nd:YLF master oscillator. Determination of pulsewidth and pulseshape was also made with detection of autocorrelation trace of CW mode-locked pulse train by using noncollinear type I Second Harmonic Generation (SHG) method. The observed TPF track showed various patterns, depending on pulse-selecting position in QSML pulse train. That is, autocorrelation of a pulse extracted at front of the train displayed smooth pulse shape, while one from the trailing part of the train created many sharp spikes and substructure in the pulse. By TPF method, pulsewidth was measured to be 44.4 ps with contrast ratio of 2.86 which enabled us to find out energy fraction of a pulse to total energy, (sum of pulse and background); we obtain the value of 0.62. Pulsewidth of 46.6ps was also acquired in another SHG experiment with the help of only mode-locked pulse train. On the other hand, we confirmed that shape of the pulse is close to $sech^2$ one as a result of fitting the SHG autocorrelation signal with various functions. With simulation using this $sech^2$ type of pulse, pulsewidth reduction of the beam, having passed through four-pass amplifier, was also verified.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.95-100
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• 2003

Competitive direct enzyme-linked immunosorbent assay(cdELISA) of aflatoxin $B_1$ ($AFB_1$) in deonjang(Korean-style soybean paste) and kochujang(fermented hot peppersoybean paste) and the level of $AFB_1$ in modern or traditional style deonjang and gochujang, produced in Korea, was surveyed by cdELISA. From the standard curve of the cdELISA, the detection limit of $AFB_1$ was 0.2 ng/m/. The average recovery of $AFB_1$ was 71.5% in the range of 1~100 ng/g after spiking $AFB_1$ into deonjang and it means that it could be possible to detect the $AFB_1$ in these range by the cdELISA in deonjang. Among the 30 kochujangs tested, no $AFB_1$ was detected in kochujangs. Among the 30 deonjangs, $AFB_1$ was detected in 6 ones in the range of 1.0~6.0 ng/g. The occurrence of $AFB_1$ in deonjang and kochujang tested in this study was less than the Korea Standard and Specification of aflatoxin in foods (10 ppb).

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.118-121
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• 2010

A HPLC-MS/MS method was developed for simultaneous determination of six sweeteners (acesulfame-K, cyclamate, saccharin, sucralose, stevioside, aspartame) in children's favorite foods. The procedure involves an extraction of the six sweeteners with 50% methanol solution, sample clean-up using the Carrez clearing reagent and filtering with cartridge filter. The HPLC separation was performed on a Hypersil Gold (150 mm ${\times}$ 2.1 mm 5 um) column using the water/acetonitrile mobile phase (95:5). Mass spectrometric analysis was carried out using the TSQ Quantum Ultra operated in negative and positive ESI/SRM. With this method, good linear relationship, sensitivity and reproducibility were obtained. The spike recoveries of six sweeteners for 2 kinds of foods spiked into 0.4 mg/ kg ranged from 87.4 to 114.7%. The detection limits were above 0.02 mg/kg. The method has been applied to determination of six sweeteners in children's favorite foods.

• Journal of Life Science
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• v.24 no.1
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• pp.54-60
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• 2014

Aromatic hydrocarbons are toxic environmental pollutants that are detrimental to the ecosystem and human health. Among them, chlorotoluene and nitrotoluene are toxic to hydrobios and irritate the skin, eyes, and respiratory organs of humans. We herein report the development of recombinant microbial biosensors for cheap and rapid monitoring of chlorotoluene and nitrotoluene compounds. Plasmids were constructed by inserting the xylR regulatory gene for BTEX (benzene, toluene, ethylbenzene, and xylene) degradation into upstream of Po' (the DmpR activator promoter Po with the deletion of its own upstream activating sequences) or Pu (the cognate promoter of XylR)::lacZ (the ${\beta}$-galactosidase gene) and transformed into Escherichia coli $DH5{\alpha}$. In the presence of inducers, the biosensor cells immobilized in agarose developed a red color in 1-2 h due to the hydrolysis of chlorophenol red ${\beta}$-D-galactopyranoside (CPRG), a substrate of ${\beta}$-galactosidase that was expressed by the inducers. Among BTEX, high responses were specifically observed with o-, m-, p-chlorotoluene ($0.1{\mu}M-100 mM$) and o-, m-, p-nitrotoluene (0.1 mM-100 mM). Po' demonstrated higher responses than those with Pu. The biosensors immobilized in agarose showed good stability after 21 days' storage at $4^{\circ}C$, and responses in untreated wastewater spiked with chlorotoluene and nitrotoluene, suggesting they can be used to detect compounds in wastewater.