• Toxicological Research
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• v.31 no.3
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• pp.299-305
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• 2015

An HPLC analytical method was validated for the quantitative determination of biogenic amines in agricultural products. Four agricultural foods, including apple juice, Juk, corn oil and peanut butter, were selected as food matrices based on their water and fat contents (i.e., non-fatty liquid, non-fatty solid, fatty liquid and fatty solid, respectively). The precision, accuracy, recovery, limit of detection (LOD) and quantification (LOQ) were determined to test the validity of an HPLC procedure for the determination of biogenic amines, including tryptamine, ${\beta}$-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine, in each matrix. The LODs and LOQs for the biogenic amines were within the range of 0.01~0.10 mg/kg and 0.02~0.31 mg/kg, respectively. The relative standard deviation (RSD) of intraday for biogenic amine concentrations ranged from 1.86 to 5.95%, whereas the RSD of interday ranged from 2.08 to 5.96%. Of the matrices spiked with biogenic amines, corn oil with tyramine and Juk with putrescine exhibited the least accuracy of 84.85% and recovery rate of 89.63%, respectively, at the lowest concentration (10 mg/kg). Therefore, the validation results fulfilled AOAC criteria and recommendations. Subsequently, the method was applied to the analysis of biogenic amines in fermented agricultural products for a total dietary survey in Korea. Although the results revealed that Korean traditional soy sauce and Doenjang contained relatively high levels of histamine, the amounts are of no concern if these fermented agricultural products serve as condiments.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1114-1119
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• 2004

The biofilms on pipe walls in water distribution systems are of interest since they can lead to chlorine demand, coliform growth, pipe corrosion, and water taste and odor problems. As such, the study described in this paper is part of an AWWARF and Tampa Bay Water tailored collaboration project to determine the effect of blending different source waters on the water quality in various distribution systems. The project was based on 18 independent pilot distribution systems (PDS), each being fed by a different water blend (7 finished waters blended in different proportions). The source waters compared were groundwater, surface water, and brackish water, which were treated in a variety of pilot distribution systems, including reverse osmosis (RO) (desalination), both membrane and chemical softening, and ozonation-biological activated carbon (BAC), resulting in a total of 7 different finished waters. The observations from this study consistently demonstrated that unlined ductile iron was more heavily colonized by a biomass than galvanized steel, lined ductile iron, and PVC (in that order) and that the fixed biomass accumulation was more influenced by the nature of the supporting material than by the water quality (including the secondary residual levels). However, although the bulk liquid water cultivable bacterial counts (i.e. heterotrophic plate counts or HPCs) did not increase with a greater biofilm accumulation, the results also suggested that high HPCs corresponded to a low disinfectant residual more than a high biofilm inventory. Furthermore, temperature was found to affect the biofilms, plus the AOC was important when the residual was between 0.6 and 2.0 mg $Cl_2/l$. An additional aspect of the current study was that the potential of the exoproteolytic activity (PEPA) technique was used along with a traditional so-called destructive technique in which the biofilm was scrapped off the coupon surface, resuspended, and cultivated on an R2A agar. Both techniques indicated similar trends and relative comparisons among the PDSs, yet the culturable biofilm values for the traditional method were several orders of magnitude lower than the PEPA values.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1800-1806
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• 2008

Cytokines play a central role in the mucosal immune response and are involved in regulation of nutrient absorption, metabolism and animal growth. This study investigated the effect of diet manipulation with specialized protein or peptide sources on expression of cytokine (IL-1, IL-6, IL-10, and TNF-${\alpha}$) mRNA abundance in different intestinal regions and at different ages post-weaning in piglets. A total of 48 (17 days of age, $6.16{\pm}0.34kg\;BW$) weanling pigs were fed either a corn-soy/whey protein basal diet, the basal diet supplemented with spray-dried plasma protein (SDPP), or the basal diet supplemented with $Peptiva^{(R)}$, a hydrolyzed marine plant protein. A fourth treatment group was fed the SDPP diet, but the feed intake level was limited (SDPP-LF). Pigs were killed at 3 and 10 d, and intestinal cytokine mRNA was measured by real-time PCR using the relative quantification method. The SDPP-LF group exhibited an increased TNF-${\alpha}$ mRNA abundance compared with the ad libitum SDPP group (p<0.05). The TNF-${\alpha}$ and IL-10 mRNA abundance increased from the proximal to distal part of the intestine, and the mRNA abundance was greater (p<0.01) in the distal intestine as compared with the proximal and middle intestine. The cytokines IL-1-${\beta}$, IL-10 and TNF-${\alpha}$ mRNA abundance also increased from d3 to d10 postweaning (p<0.01). In summary, restricted feeding increased the TNF-${\alpha}$ mRNA abundance in the small intestine, however neither SDPP nor peptide supplementation affected cytokine mRNA expression. Abundance of mRNA for most cytokines examined in this study increased with age post-weaning, suggesting that during 10 d after weaning the mucosal immune system is still under development.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.630-636
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• 2013

Recently, there has been a growing body of evidence showing that cellular microRNAs (miRNAs) are involved in virus-host interactions. Numerous studies have focused on analyses of the expression profiles of cellular miRNAs, but the expression patterns of Dicer, which is responsible for the generation of miRNAs, have only rarely been explored in Gallus gallus. We developed a duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay for the relative quantification of the mRNAs of Dicer and ${\beta}$-actin in G. gallus. To apply this method, the expression of Dicer in avian cells after infection with avian leukosis virus subgroup J (ALV-J) was detected using our established duplex real-time RT-PCR. The duplex real-time RT-PCR assay is sufficiently sensitive, specific, accurate, reproducible, and cost-effective for the detection of Dicer in G. gallus. Furthermore, this study, for the first time, demonstrated that ALV-J can induce differential expression of Dicer mRNA in the ALV-J-infected cells.

• Analytical Science and Technology
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• v.31 no.2
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• pp.88-95
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• 2018

A simple, sensitive, and selective high-performance liquid chromatography (HPLC) method was developed and validated for the simultaneous quantification of fluorometholone (FLU) and tetrahydrozoline hydrochloride (THZ) in combined ophthalmic formulations. The effects of several factors, including detection wavelength, buffer pH, buffer concentration, and organic solvent concentration, on the performance of the method were investigated. The performance of the developed method was validated in accordance with the requirements of the International Conference on Harmonization. The linearity of the calibration curves in the desired concentration range was high for both FLU and THZ ($r^2=0.9999$). The accuracy and precision of the method were determined by a recovery study at analyte concentrations of 80 %, 100 %, and 120 %. The recovery was 99.60-100.17 % for both analytes, with a relative standard deviation less than 1.0 % at any concentration level. The validated results indicate that the new HPLC method could be successfully applied for the simultaneous determination of FLU and THZ in ophthalmic suspensions.

• Smart Structures and Systems
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• v.3 no.3
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• pp.341-356
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• 2007

A good understanding of normal modal variability of civil structures due to varying environmental conditions such as temperature and wind is important for reliable performance of vibration-based damage detection methods. This paper addresses the quantification of wind-induced modal variability of a cable-stayed bridge making use of one-year monitoring data. In order to discriminate the wind-induced modal variability from the temperature-induced modal variability, the one-year monitoring data are divided into two sets: the first set includes the data obtained under weak wind conditions (hourly-average wind speed less than 2 m/s) during all four seasons, and the second set includes the data obtained under both weak and strong (typhoon) wind conditions during the summer only. The measured modal frequencies and temperatures of the bridge obtained from the first set of data are used to formulate temperature-frequency correlation models by means of artificial neural network technique. Before the second set of data is utilized to quantify the wind-induced modal variability, the effect of temperature on the measured modal frequencies is first eliminated by normalizing these modal frequencies to a reference temperature with the use of the temperature-frequency correlation models. Then the wind-induced modal variability is quantitatively evaluated by correlating the normalized modal frequencies for each mode with the wind speed measurement data. It is revealed that in contrast to the dependence of modal frequencies on temperature, there is no explicit correlation between the modal frequencies and wind intensity. For most of the measured modes, the modal frequencies exhibit a slightly increasing trend with the increase of wind speed in statistical sense. The relative variation of the modal frequencies arising from wind effect (with the maximum hourly-average wind speed up to 17.6 m/s) is estimated to range from 1.61% to 7.87% for the measured 8 modes of the bridge, being notably less than the modal variability caused by temperature effect.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.2
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• pp.65-71
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• 2008

A monsoon season monitoring data from June to September, 2005 of a small forested watershed located at the upstream of the North Han River system in Korea was conducted to analyze the flow variations, the NPS pollutant concentrations, and the pollution load characteristics with respect to sampling frequencies. During the 4-month period, 1,423 mm or 79.2% of annual rainfall(1,797 mm) were occurred and more than 77%, 54% and 68% of annual T-N, $NO_3$-N and T-P loads discharged. Flow rate was continuously measured with automatic velocity and water level meters and 58 water quality samples were taken and analyzed. It was analyzed that the flow volume by random measurement varied very widely and ranged from 79% to 218% of that of continuous measurement. It was recommended that flow measurement of small forested watersheds should be continuously measured with automated flow meters to precisely measure flow rates. Flow-weighted mean concentrations of T-N, $NO_3$-N and T-P during the period were 2.114 mg/L, 0.836 mg/L, and 0.136 mg/L, respectively. T-N, $NO_3$-N and T-P loads were sensitive to the number of samples. And it was analyzed that in order to measure the pollution load within the error of 10% to the true load, the rate of sampling frequency should be higher than 89.7% of the sample numbers that were required to compute the true pollution load. If it is compared to selected foreign research results, about 10 water samples for each rainfall event were needed to compute the pollution load within 10% error. It is unlikely in Korea and recommended that thorough NPS pollution monitoring studies are required to develop the standard monitoring procedures for reliable NPS pollution quantification.

• Archives of Pharmacal Research
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• v.27 no.9
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• pp.901-905
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• 2004

A rapid, sensitive and selective hydrophilic interaction liquid chromatography-tandem mass spectrometric(HILIC-MS/MS) method for the determination of tiapride in human plasma was developed. Tiapride and internal standard, metoclopramide were extracted from human plasma with dichloromethane at basic pH and analyzed on an Atlantis HILIC silica column with the mobile phase of acetonitrile-ammonium formate (190 mM, pH 3.0) (94：6, v/v). The ana-Iytes were detected using an electrospray ionization tandem mass spectrometry in the multi-ple-reaction-monitoring mode. The standard curve was linear (r＝0.999) over the concentration range of 1.00-200 ng/mL. The coefficient of variation and relative error for intra- and inter-assay at three QC levels were 6.4∼8.8％ and -2.0∼3.6％, respectively. The recoveries of tiapride ranged from 96.3 to 97.4％, with that of metoclopramide (internal standard) being 94.2％. The lower limit of quantification for tiapride was 1.00 ng/mL using 1 00 $\mu$L of plasma sample.

• Journal of Wetlands Research
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• v.18 no.1
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• pp.84-93
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• 2016

As a transition region between ocean and land, coastal wetlands are significant ecosystems that maintain water quality, provide natural habitat for a variety of species, and slow down erosion. The energy of coastal waves and storm surges are reduced by vegetation cover, which also helps to maintain wetlands through increased sediment deposition. Wave attenuation by vegetation is a highly dynamic process and its quantification is important for understanding shore protection and modeling coastal hydrodynamics. In this study, laboratory experiments were used to quantify wave attenuation as a function of vegetation type as well as wave conditions. Wave attenuation characteristics were investigated under regular waves for rigid model vegetation. Laboratory hydraulic test and numerical analysis were conducted to investigate regular wave attenuation through emergent vegetation with wave steepness ak and relative water depth kh. The normalized wave attenuation was analyzed to the decay equation of Dalrymple et al.(1984) to determine the vegetation transmission coefficients, damping factor and drag coefficients. It was found that drag coefficient was better correlated to Keulegan-Carpenter number than Reynolds number and that the damping increased as wave steepness increased.

• The Korea Journal of Herbology
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• v.31 no.3
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• pp.29-35
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• 2016

Objectives : Ijung-tang (IJT) is a traditional herbal formula and has been used to treat digestive diseases such as abdominal pain, vomiting, and diarrhea. IJT consists of four herbal medicines, Ginseng radix, Atractylodis rhizoma alba, Zingiberis rhizoma, and Glycyrrhizae radix et rhizoma, containing various bioactive compounds. Quality assesment of IJT preparations was performed by analytical method for determining marker compounds.Methods : Determination of seven marker compounds in IJT preparations was quantitatively conducted by high-performance liquid chromatography equipped with a diode-array detector. The marker compounds were separated on a reversed-phase C18 column and the analytical method was successfully validated. Chemometric analysis was performed to compare IJT water extracts and commercial IJT granules.Results : Limit of detection and limit of quantification values were in the ranges of 0.093-2.649 μg/mL and 0.283-8.027 μg/mL, respectively. Precisions were 0.30-3.87% within a day and 0.23-2.35% over three consecutive days. Recoveries of the marker compounds ranged from 87.35-107.05%, with relative standard deviation (RSD) values < 6.15%. Repeatabilities were < 1.20% and < 1.71% of RSD value for retention time and absolute peak area, respectively. The results from quantitative analysis showed that the quantities of seven marker compounds of IJT samples varied, as were found in principal component analysis and hierarchical clustering analysis.Conclusions : The analytical method developed in the present study was precise and reliable to simultaneously determine marker compounds of IJT. Therefore, it can be used for the quality assessment of IJT preparations.