• Journal of the Korean Society for Marine Environment & Energy
• /
• v.17 no.3
• /
• pp.212-223
• /
• 2014

For the better understanding of long-term and seasonal variations of water quality in Masan Bay, South Sea of Korea, we analyzed the archive data monitored at three stations of the bay during the last 13 years (2000-2012). The average concentrations of the chemical oxygen demand (COD), the dissolved inorganic nitrogen (DIN) and the dissolved inorganic phosphorus (DIP) during the monitoring period are $2.70{\pm}0.09{\mu}/L$, $19.66{\pm}1.84{\mu}m$ and $1.39{\pm}0.13{\mu}m$ in surface water, respectively, and $2.22{\pm}0.07{\mu}/L$, $18.53{\pm}1.36{\mu}m$ and $1.47{\pm}0.12{\mu}m$ in bottom water, respectively. The trophic state of the surface water was the eutrophic level in Masan Bay during the four seasons. The DIN concentrations of both surface and bottom waters increased from August to November and showed the highest average in November. However, The DIN decreased from February to May and showed the lowest average in May. The concentrations of the DIP and the dissolved silicate (DSi) in bottom waters had the highest averages in August because of the high water temperature and oxygen deficient condition. The results of correlation analysis and factor analysis showed that the main factors of surface waters were inflow of nutrients from terrestrial areas and internal production, and the main factors of bottom waters were the variations of the dissolved oxygen (DO), the DIP, and the DSi. The DIN and DIP average concentrations (2007~2012) had decreased in range of 68.1%~76.0% and 66.2~76.6%, respectively from 2007 in which the "Regulation of Total Emission" was established in Masan Bay. Therefore, it could have had positive effects on water quality improvement to take the "Regulation of Total Emission" and other actions such as reducing water pollutions in Masan Bay from 2007.

• Korean Journal of Environmental Agriculture
• /
• v.40 no.4
• /
• pp.353-358
• /
• 2021

BACKGROUND: Prochloraz has been widely used as an imidazole fungicide on fruits and vegetables in Korea. Analytical approaches to evaluate prochloraz residues in herbal medicine are required for their safety management. In this study, we developed a GC-ECD method for quantitative determination of prochloraz in Platycodi Radix. The metabolite 2,4,6-trichlorophenol (2,4,6-T) was used as a target compound to evaluate total prochloraz residues as it is categorized to a representative residue definition of prochloraz. All residues containing 2,4,6-T were converted to 2,4,6-T and subjected to GC-ECD. METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining prochloraz and it metabolite 2,4,6-T in Platycodi Radix. Prochloraz and its metabolite 2,4,6-T residuals were extracted using acetone. The extract was diluted with and partitioned directly into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was decomposed to 2,4,6-T, and then the partitioned ion-associate was finally purified by optimized aminopropyl solid-phase extraction (SPE). The limits of quantitation of the method (MLOQs) were 0.04 mg/kg and 0.02 mg/kg, respectively for prochloraz and 2,4,6-T, considering the maximum residue level (MRL) of prochloraz as 0.05 mg/kg in Platycodi Radix. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (82.1-89.7%). Good reproducibilities were obtained (coefficient of variation < 2.8%), and the linearities of calibration curves were reasonable (r² > 0.9986) in the range of 0.005-0.5 ㎍/mL. CONCLUSION(S): The method developed in this study was successfully validated to meet the guidelines required for quantitative determination of pesticides in herbal medicine. Thus, the method could be useful to monitor prochloraz institutionally in herbal medicine.

• Journal of Life Science
• /
• v.29 no.7
• /
• pp.800-808
• /
• 2019

Charcot-Marie-Tooth disease (CMT) is a group of rare peripheral neuropathies characterized by progressive muscle weakness and atrophy and areflexia in the upper and lower extremities. The most common subtype of CMT is CMT1A, which is caused by a tandem duplication of the PMP22 gene in the 17p12 region. Patients with CMT1A show a loose genotype-phenotype correlation, which suggests the existence of secondary genetic or association factors. Recently, polymorphisms of rs71428439 (n.83A>G) and rs2292832 (n.86T>C) in the MIR149 have been reported to be associated with late onset and mild phenotypic CMT1A severity. The aim of this study was to examine the intrafamilial heterogeneities of clinical phenotypes according to the genotypes of these two SNPs in MIR149. For this study, we selected 6 large CMT1A families who showed a wide range of phenotypic variation. This study suggested that both SNPs were related to the onset age and severity in the dominant model. In particular, the AG+GG (n.83A>G) and TC+CC genotypes (n.86T>C) were associated to late onset and mild symptoms. Motor nerve conduction velocity (MNCV) was not related to the MIR149 genotypes. These results were consistent with the previous studies. Therefore, we suggest that the rs71428439 and rs2292832 variants in MIR149 may serve as genetic modifiers of CMT1A intrafamilial phenotypic heterogeneity, as they have a role in the unrelated patients. This is the first study to show an association using large families with variable clinical CMT1A phenotypes. The results will be helpful in the molecular diagnosis and treatment of patients with CMT1A.

• Journal of Food Hygiene and Safety
• /
• v.38 no.5
• /
• pp.361-372
• /
• 2023

Organotin pesticide is used as an acaricide in agriculture and may contaminate livestock products. This study aims to develop a rapid and straightforward analytical method for detecting organotin pesticides, specifically azocyclotin, cyhexatin, and fenbutatin oxide, in various livestock products, including beef, pork, chicken, egg, and milk, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The extraction process involved the use of 1% acetic acid in a mixture of acetonitrile and ethyl acetate (1:1). This was followed by the addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium chloride. The extracts were subsequently purified using octadecyl (C₁₈) and primary secondary amine (PSA), after which the supernatant was evaporated. Organotin pesticide recovery ranged from 75.7 to 115.3%, with a coefficient of variation (CV) below 25.3%. The results meet the criteria range of the Codex guidelines (CODEX CAC/GL 40). The analytical method in this study will be invaluable for the analysis of organotin pesticides in livestock products.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.15 no.1
• /
• pp.8-15
• /
• 2010

An experiment was conducted to evaluate the biologically adverse effect of increased carbon dioxide in seawater on marine bacteria, Vibrio fischeri. We measured the bioluminescence and cell density at every 6 hours for 24 hours of the whole incubation period after exposing test microbes to a range of $CO_2$ concentration such as 380(Control), 1,000, 3,000, 10,000 and 30,000 ppm, respectively. Significant effect on relative luminescence(RLU) of V. fischeri was observed in treatments with $CO_2$ concentration higher than 3,000 ppm at t=12 h. However, the difference of RLU among treatments significantly decreased with the incubation time until t=24 h. Similar trend was observed for the variation of cell density, which was measured as optical density using spectrophotometer. The results showed that a significant relationship between $CO_2$ concentration and bioluminescence of test microbes was observed for the mean time. However, the inhibition of relative bioluminescence and also cell density could be recovered at the concentration levels higher than 3,000 ppm. The dissolved $CO_2$ can be absorbed directly by cell and it can decrease the intracellular pH. Our results implied that microbes might be adversely affected at the initial growing phase by increased $CO_2$. However, they could adapt by increasing ion transport including bicarbonate and then could make their pH back to normal level. Results of this study could be supported to understand the possible influence on marine bacteria by atmospheric increase of $CO_2$ in near future and also by released $CO_2$ during the marine $CO_2$ sequestration activity.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.1
• /
• pp.1-10
• /
• 1996

The contents of heavy metals in soil near the Janghang smelter area were observed to understand present status and relationship between their fraction and the absorption by rice. The soil samples were taken from the eight sites of the paddy fields in 1982 and 1990, and analysis on heavy metals including Cd, Zn, Cu and Pb was performed. The results were as follows: Total contents of heavy metals in the samples of 1990 were higher than those of 1982. The order of increasing ratio was Cu > Zn > Pb > Cd and the variation of Cd content by sequential differente extracting was residual > exchangeable > dilute acid-extractable fractions and its increasing range was from 38 to 71% during nine years. The ratio of immobile heavy metals bound within an oxide or silicate matrix of Fe-Mn oxide bound and residual in surface soil was that Cd, Pb, Cu and Zn were 31.65, 42.22, 76.57 and 79.49%, respectively, and their mobile ratios of exchangeable, dilute acid-extractable and organically bound were more than 20.28%. Those of mobile Cd, Pb, Cu and Zn were 68.35, 55.78, 23.43 and 20.28%, respectively. Correlation between the heavy metal contents in surface soil and those in tissue of rice plant, such as leaf blade, leaf sheath, stem and panicle axis, were significant, but were not significant in subsurface soil. The dilute acid-extractable and organically bound fractions of Cd, Cu, Pb and Zn in surface soil were more significantly correlated with those in tissues of paddy rice.

• Korean Journal of Plant Resources
• /
• v.31 no.5
• /
• pp.498-514
• /
• 2018

A statistical analysis for 3651 genetic resources collected from China (1,542), Japan (1,409), Korea (413), and India (287) was conducted using normal distribution, variability index value (VIV), analysis of variation (ANOVA) and Ducan's multiple range test (DMRT) based on a data obtained from NIRS analysis. In normal distribution, the average protein content was 8.0%, whereas waxy type amylose and common rice amylose were found to be 8.7% and 22.7%, respectively. The protein contents ranged from 5.4 to 10.6% at the level of 95%. The waxy amylose and common rice amylose ranged from 5.9 to 11.5%, and from 16.9 to 28.5% at 95% confidence level, respectively. The VIV was 0.59 for protein, 0.64 for low amylose, and 0.81 for high amylose contents. The average amylose contents were 18.85% in Japanese, 19.99% in Korean, 20.27% in Chinese, and 25.46% in Indian resources, while the average protein contents were found to be 7.23% in Korean, 7.73% in Japanese, 8.01% in Chinese, and 8.17% in Indian resources. The ANOVA of amylose and protein content showed significant differences at the level of 0.01. The F-test for amylose content was 158.34, and for protein content 53.95 compared to critical value 3.78. The DMRT of amylose and protein content showed significant difference (p<0.01) between resources of different countries. Japanese resources had the lowest level of amylose contents, whereas, the lowest level of protein content was found in Korean resources compared to other origins. Indian resources showed the highest level of amylose and protein contents. It is recommended these results should be helpful to future breeding experiments.

• 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.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.24 no.3
• /
• pp.375-388
• /
• 2019

Accurate evaluation of sea-to-air $CO_2$ flux and its variability is crucial information to the understanding of global carbon cycle and the prediction of atmospheric $CO_2$ concentration. $fCO_2$ observations are sparse in space and time in the East Sea. In this study, we derived high resolution time series of surface $fCO_2$ values in the southwest East Sea, by feeding sea surface temperature (SST), salinity (SSS), chlorophyll-a (CHL), and mixed layer depth (MLD) values, from either satellite-observations or numerical model outputs, to three machine learning models. The root mean square error of the best performing model, a Random Forest (RF) model, was $7.1{\mu}atm$. Important parameters in predicting $fCO_2$ in the RF model were SST and SSS along with time information; CHL and MLD were much less important than the other parameters. The net $CO_2$ flux in the southwest East Sea, calculated from the $fCO_2$ predicted by the RF model, was $-0.76{\pm}1.15mol\;m^{-2}yr^{-1}$, close to the lower bound of the previous estimates in the range of $-0.66{\sim}-2.47mol\;m^{-2}yr^{-1}$. The time series of $fCO_2$ predicted by the RF model showed a significant variation even in a short time interval of a week. For accurate evaluation of the $CO_2$ flux in the Ulleung Basin, it is necessary to conduct high resolution in situ observations in spring when $fCO_2$ changes rapidly.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.11 no.1
• /
• pp.103-111
• /
• 2009

This study was carried out to determine effects of long-term supply of Cordyceps militaris mycelia on cordycepin content in milk in dairy cows. Ten Holstein cows in the early stages of lactation were divided into two groups. Control group received no supplement whereas treatment group received 6% of C. militaris mycelia of their dry matter intake for 6 months. Feed intake, milk urea nitrogen and somatic cell counts were not affected by long-term supply of C. militaris mycelia for the whole period. In addition, milk yield and milk composition were not affected by long-term supply of C. militaris mycelia at any time of the periods with the exception of milk protein content and yield. The average of milk protein content and yield from the whole period was higher for C. militaris mycelia supplement group than for the control group. As expected, cordycepin in whole blood and milk was not detected in the control group. The range of cordycepin content in the treatment was 0.31~0.38µ/ml and 0.18~0.26(µ/ml for whole blood and milk, respectively. Individual variation was found to be very high and, furthermore cordycepin was undetected in some milk samples. Thus, no clear pattern could be seen in cordycepin content in milk throughout the whole period. Overall, the results of the present study suggest that the transfer efficiency of cordycepin to milk by supplementing C. militaris mycelia in dairy cows was unpredictable and low.