• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.1-7
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• 2014

The present study was performed to investigate the pre-harvest residue limit (PHRL) of pesticides namely, metalaxyl-M and flusilazole in oriental melon, and to identify the biological half-life and characteristics of their residues. In this study, pesticides were sprayed once as single spray and double spray on oriental melon. The oriental melon samples were collected at 0, 1, 2, 3, 5, 7, 9 and 11 days before harvest and samples were extracted with QuEChERS method. The residues of both the pesticides were quantified using GC/NPD and LC/MS/MS. The limit of detection was found to be 0.02 mg/kg and 0.01 mg/kg and their recoveries were greater than 95% (95.7% ~ 103.2% for metalaxyl-M and 100.2% ~ 106.8% for flusilazole) for both pesticides. The biological half-lives of both metalaxyl-M and flusilazole were 12 days at single and double spray, respectively. The PHRL of metalaxyl-M and flusilazole was found 1.0 mg/kg and 0.3 mg/kg, respectively for 10 days before harvest. The results of the present study shows the residual level of both the pesticides metalaxyl-M and flusilazole in oriental melon were less than their maximum residual limits.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.77-83
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• 2013

This study was performed to investigate pre-harvest residue limit (PHRL) in amaranth, to estimate biological half-life of emamectin benzoate and identify the characteristics of the residue. Pesticides of standard and double appplication rate, were sprayed once on amaranth at 0, 1, 2, 3, 5, 7, 10, 14 days before harvest. Amaranth sample was extracted with acetonitrile and partitioned with dichloromethane, and pesticide residues were determined with LC/MS/MS. The limit of detection of emamectin benzoate was 0.01 mg/kg. Recoveries of emamectin benzoate ($B_{1a}$, $B_{1b}$) at two fortification levels of 0.1 and 0.5 mg/kg, $B_{1a}$ were $93.3{\pm}0.7%$ and $93.2{\pm}7.7%$, $B_{1b}$ were $106.6{\pm}1.9%$ and $80.5{\pm}6.6%$, respectively. The biological half-lives of emamectin benzoate were about 2.0 days at standard application rate and 1.7 days at double application rate, respectively. The PHRL of emamectin benzoate were recommended as 0.84 mg/kg for 10 days before harvest.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8503-8512
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• 2016

The purpose of this study was to provide a detailed explanation of the mechanism of bisanthracycline, WP 631 in comparison to doxorubicin (DOX), a first generation anthracycline, currently the most widely used pharmaceutical in clinical oncology. Experiments were performed in SKOV-3 ovarian cancer cells which are otherwise resistant to standard drugs such as cis-platinum and adriamycin. As attention was focused on the ability of WP 631 to induce apoptosis, this was examined using a double staining method with Annexin V and propidium iodide probes, with measurement of the level of intracellular calcium ions and cytosolic cytochrome c. The western blotting technique was performed to confirm PARP cleavage. We also investigated the involvement of caspase activation and DNA degradation (comet assay and immunocytochemical detection of phosphorylated H2AX histones) in the development of apoptotic events. WP 631 demonstrated significantly higher effectiveness as a pro-apoptotic drug than DOX. This was evident in the higher levels of markers of apoptosis, such as the externalization of phosphatidylserine and the elevated level of cytochrome c. An extension of incubation time led to an increase in intracellular calcium levels after treatment with DOX. Lower changes in the calcium content were associated with the influence of WP 631. DOX led to the activation of all tested caspases, 8, 9 and 3, whereas WP 631 only induced an increase in caspase 8 activity after 24h of treatment and consequently led to the cleavage of PARP. The lack of active caspase 3 had no outcome on the single and double-stranded DNA breaks. The obtained results show that WP 631 was considerably more genotoxic towards the investigated cell line than DOX. This effect was especially visible after longer times of incubation. The above detailed studies indicate that WP 631 generates early apoptosis and cell death independent of caspase-3, detected at relatively late time points. The observed differences in the mechanisms of the action of WP631 and DOX suggest that this bisanthracycline can be an effective alternative in ovarian cancer treatment.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.270-276
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• 1999

Background: Extended-spectrum ${\beta}$-lactamases(ESBL) are enzymes that confer resistance to oxyimino-${\beta}$-lactams as well as to penicillins and cephalosporins. Strains of Klebsiella pneumoniae and Escherichia coli that produce ESBL have been increasingly prevalent in many countries. The purpose of this study was to investigate the ESBL production rate of K. pneumoniae and E. coli at the in Yeungnam University Medical Center. Materials and Methods: Thirty-one isolates of K pneumoniae and twenty-five isolates of E. coli were examined for ESBL by double disk synergy test, using 20/$10{\mu}g$ ticarcillin/clavulanic acid and $30{\mu}g$ oxyimino-${\beta}$-lactam(ceftazidime, ceftaxime, ceftriaxone and aztreonam) disks. Results: Fifty-two percent of K. pneumoniae and sixteen percent of E. coli isolates revealed double disk synergism. Majority of ESBL-producing strains(fifty-five percent) were isolated from patients in the intensive care unit. Conclusion: ESBL production of K. pneumoniae and E. coli were also common at the Yeungnam University Medical Center and pose a serious problem for antimicrobial therapy.

• Research in Plant Disease
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• v.13 no.1
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• pp.71-73
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• 2007

Field disease incidences of squash virus diseases in Jeonnam province were estimated to be 76.1% and of delayed planting on August-September (retarding culture) and on February-March (semi-forcing culture) on glass house were 55.0% and 0%, respectively, in 2000. Disease incidences of individual squash plant within a field were 100% and 3.6%, respectively, in wild culture and retarding culture. Total of 61 samples suspected to be infected with viruses were collected in 2000 and tested by RT-PCR using specific oligonulceotide primer sets designed for the detection of Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), Zucchini yellow mosaic virus (ZYMV), Papaya ring spot virus (PRSV), Watermelon mosaic virus (WMV), and Cucumber mosaic virus (CMV). Each specific primer set for WMV, ZYMV, and PRSV amplified expected size of DNA fragments from 16, 10, and 2 samples in wild culture, respectively. Double or triple infection were observed in 7 samples tested. In contrast, each specific primer set for WMV, ZYMV, and PRSV confirmed virus infection from 7, 6, and 6 samples, respectively, in samples collected from semi-forcing culture. Double infection of WMV and PRSV was observed in only one sample. However, no DNA fragment was amplified from RT-PCR using CGMMV, KGMMV, and CMV specific oligonucleotide primer sets indicating no CGMMV, KGMMV, or CMV infection in squash fields in Jeonnam province in 2000.

• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.45-51
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• 2012

BACKGROUND: This study was carried out to establish pre-harvest residue limit of fungicides pyrimethanil and trifloxystrobin in persimmon, based on dissipation and biological half-lives of two fungicides residue. METHODS AND RESULTS: Both pyrimethanil and trifloxystrobin were extracted with acetonitrile, clean-up with $NH_2$ SPE cartridge and residue were analyzed by HPLC/DAD. Limit of Detection was 0.01 mg/kg. Average recovery were $81{\pm}1.62%$, $98{\pm}1.58%$ of pyrimethanil, and $91{\pm}2.94%$, $98{\pm}1.25%$ of trifloxystrobin at fortification levels at 0.1 and 0.5 mg/kg, respectively. CONCLUSION: The biological half-lives of pyrimethanil were 15.6 and 11.6 days at sprayed with recommended and double dosage, respectively. The biological half-lives of trifloxystrobin were 10.4 and 10.3 days at sprayed with recommended and double dosage, respectively. The pre-harvest residue limit of pyrimethanil and trifloxystrobin were recommended as 2.69 and 0.83 mg/kg for 10 days before harvest, respectively.

• Geophysics and Geophysical Exploration
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• v.18 no.1
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• pp.31-34
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• 2015

A gravity meter has been used for exploring subsurface mineral resources and monitoring long-period events such as Earth tides. Recently, researchers found several other intriguing features that we could even detect large teleseismic earthquakes and monitor seismic ambient noise using gravimeters. The zero-length spring suspension technology gives the gPhone (Micro-g LaCoste) excellent low frequency sensitivity, which may have implications for investigating much longer-period natural events (e.g., Earth's hum, tsunami waves, etc.). In this study, we present preliminary results through temporary operation of the gPhone at Geumsan in South Korea for 9 months (Nov. 2008-Jul. 2009). The gPhone successfully recorded large teleseismic events and showed a clear seasonal variation of the Double frequency microseisms during its operation period.

• Korean Journal of Remote Sensing
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• v.18 no.4
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• pp.209-220
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• 2002

We carried out studies on SAR image intensity and interferometric phase over oyster sea farms. Strong backscattering was observed in amplitude images, and that was considered as a radar signal double bouncing from horizontal bars. These sea farming structures are not visible in satellite optical images except IKONOS image, so that it demonstrates the value of radar remote sensing as an effective tool in support of sea farm detection. The intensity of the image is sensitive to system parameters including wavelength, polarization, and look direction, but does not correlate to tide height. We found that the strongest backscattering can be obtained by L-band HH-polarization with a look direction perpendicular to the horizontal bar. We also succeeded in generating 21 coherent JERS-1 SAR interferometric pairs over the oyster farms. The general trend of the fringe rate of the interferometric phases appeared to be governed by altitude of ambiguity. The general trend was modeled by an inverse function and removed to have a residual phase. The residual phase showed a linear relation with the tide height. The results demonstrate for the first time that SAR can possibly be used to estimate sea level. However, the r.m.s. error of a regression line is 11.7 cm, and that is so far too large to make reliable assessments of sea level in practical applications. Further studies is required to improve the accuracy specifically using multi-polarization SAR data.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.167-172
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• 2010

An immunochromatograhy (IC) based infectious bursal disease virus (IBDV) detection kit, which employed two anti-IBDV VP2 monoclonal antibodies, was evaluated for rapid diagnosis of infectious bursal disease virus (IBD). The detection limit of the IC kit for IBDV was $10^{3.1}$ to $10^{3.9}$ $EID_{50}$/mL, indicating that the IC kit detected IBDV sensitively as same as double antigen capture ELISA but less than a RT-PCR assay. The IC kit did not detect other viral pathogens such as Newcastle disease virus, infectious bronchitis, avian influenza virus, and infectious larynotracheitis virus. When applied to tissue samples of experimental chickens died 3 or 4 days post infection after very virulent IBDV (strain Kr/D62) infection, the IC kit detected IBDV in all samples of the bursa of Fabricius, spleen, kidney, cecal tonsil and in 87.5%, 37.5% and 0% of liver, thymus and proventriculus samples. In particular, BF tissue samples showed stronger signal bands than other tissues. Positive signal was observed. All except for one thymus sample of samples having negative results by the IC kit showed the same result with DAS-ELISA but RT-PCR assay detected IBDV in some of IC kit negative samples of thymus and proventriculus. When swab samples from the bursa of Fabricius of dead chickens (n=231) on field farms were tested, the sensitivity and specificity of the IC assay relative to RT-PCR was 100% (109/109) and 97.5% (119/122), respectively and kappa value between both assay was 0.97. The kit can provide a useful aid for rapid detection of IBDV in chickens under field circumstances.

• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.117-126
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• 2009

Purpose : A numerical method of designing a multiple quantum filter (MQF) is presented for the optimum detection of myo-inositol (mI), an important brain metabolite, by using in vivo proton nuclear magnetic resonance spectroscopy ($^1$-HMRS). Materials and Methods : Starting from the characterization of the metabolite, the filter design includes the optimization of the sequence parameters such as the two echo times (TEs), the mixing time (TM), and the flip angle and offset frequency of the 3rd $90^{\circ}$ pulse which converts multiple quantum coherences (MQCs) back into single quantum coherences (SQCs). The optimized filter was then tested both in phantom and in human brains. Results : The results demonstrate that the proposed MQF can improve the signal-to-background ratio of the target metabolite by a factor of more than three by effectively suppressing the signal from the background metabolites. Conclusion : By incorporating a numerical method into the design of MQFs in $^1$-HMRS the spectral integrity of a target metabolite, in particular, with a complicated spin system can be substantially enhanced.