• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.495-497
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• 2015

Galaxies can be "pre-processed" in the low-density outskirts by ambient medium in the filaments or tidal interactions with other galaxies while falling into the cluster. In order to probe how early on and by which mechanisms galaxies can be affected before they enter high-density cluster environments, we are carrying out an atomic hydrogen ($H\small{I}$) imaging study of a sample of galaxies selected from three filamentary structures around the Virgo cluster. Our sample consists of 14 late-type galaxies, which are potentially interacting with their surroundings. The $H\small{I}$ observations have been done using the Westerbork Synthesis Radio Telescope, the Giant Metrewave Radio Telescope, and the Jansky Very Large Array with column density sensitivity of ${\approx}3-5{\times}10^{19}cm^{-2}$ in $3{\sigma}$ per channel, which is low enough to detect faint $H\small{I}$ features in the outer disks of galaxies. In this work, we present the Hi data of two galaxies that were observed with GMRT. We examine the $H\small{I}$ morphology and kinematics to find the evidence for gas-gas and/or tidal interactions, and discuss which mechanism(s) could be responsible for pre-processing in these cases.

• Journal of the Korean Chemical Society
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• v.39 no.4
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• pp.288-293
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• 1995

The separation and determination of boron with chromotropic acid (1,8-Dihydroxynaphthalene-3,6-disulfonic acid) as a complex agent has been studied using ion pair liquid chromatography. The use of tetrabutylammonium bromide added as an ion pair reagent to mobile phase (MeOH 61%, phosphate buffer 39% pH=8.5) allowed good separation of boron-chromotrophic acid complex anion and chromotrophic acid on poly(styrene-divinylbenzene) based reversed phase column (PRP-1, 15 $cm{\times}4.6$ mm i.d.). The complex formation between boric acid and chromotrophic acid was enhanced in the presence of 0.1 M tetrabutylammonium bromide, resulting in high sensitivity. The linear calibration was achieved over the boron concentration range of 0.5∼1000 ${\mu}g/L.$ The detection limit was 0.5 ${\mu}g/L$ (S/N=2). The proposed method was applied to the determination of boron in commercially available chemicals, $Na_2SO_4$, NaOH, KCl.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.221-228
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• 2018

BACKGROUND: Spoilage fungi can reduce the shelf life of fresh fruits and cause economic losses by lowering quality. Especially, mulberry fruits have high sensitivity to fungal attack due to their high water content (> 70%) and soft texture. In addition, the surface of these fruits is prone to damage during harvesting and postharvest handling. However, any study on postharvest spoilage fungi in mulberry fruit has not been reported in Korea. This study aimed to examine the spoilage fungi occurring in mulberry fruits during storage after harvest. METHODS AND RESULTS: In this study, we isolated postharvest spoilage fungi from mulberry fruits stored in refrigerator (fresh fruits) and deep-freezer (frozen fruits) and identified them. In the phylogenetic analysis based on comparisons of the ITS rDNA sequences, the 18 spoilage fungi isolated from mulberry fruits and the 25 reference sequences were largely divided into seven groups that were subsequently verified by high bootstrap analysis of 73 to 100. Alternaria spp. including A. alternate and A. tenuissima, were the most frequently isolated fungi among the spoilage isolates: its occurrence was the highest among the 18 isolates (38.9%). CONCLUSION: The findings of this study will be helpful for increasing the shelf life of mulberry fruits through the application of appropriate control measures against infection by spoilage fungi during storage.

• IMMUNE NETWORK
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• v.1 no.3
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• pp.221-229
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• 2001

Background: Inactivation of tumor suppressor genes is believed to be important in the development of many human malignancies. Recently, several lines of evidence have indicated that the wild type p53 gene located at 17p13.3, may function as a tumor suppressor gene and that a mutant p53 gene could promote transformation by inactivating normal p53 function in a dominant negative fashion. These broad spectrum of p53 mutation in human cancers provide that mutant p53 and their protein may be potential targets of tumor diagnostic and therapeutic interventions. Method: Colony formation was performed to investigate growth suppressional ability. p53 expression pattern was examined by western blot and p53-mediated transactivation ability was assessed by CAT activity. SNU C2A cells were observed in apoptotic aspects induced by etoposide and $H_2O_2$ treatment, detecting sensitivity on agent, DNA fragmentation through agarose gel, chromatin condensation by fluorescence microscope, and cell cycle distribution by FACS. Result: 1) p53 mutant his179arg ($histidine{\rightarrow}arginine$) detected in SNU C2A cells lost transcriptional activity and growth suppression ability, showing dominant negative effect on its wild type p53. 2) Etoposide-treated SNU C2A cells induced apoptosis, exhibiting dramatic reduction of cell growth, DNA fragmentation, nuclear condensation formation of apoptotic body and increment of sub-G1 cell fraction. 3) Etoposide and $H_2O_2$-treated SNU C2A cells have no high increase of p53 expression and overexpressed p53 protein changed localization, from cytoplasm to nucleus. Also, p53-mediated transcriptional activity was increased by agents-treatment. Conclusion: SNU C2A cells coexpress wild-type and mutant p53 protein induced apoptosis in the condition on DNA damage, through localizational shift from cytoplasm to nucleus of p53 protein rather than the induction of p53 protein. SNU C2A cells derived mutant p53 his179arg abrogated both the growth supression ability and transactivational activity, showing inhibition effect on transcriptional activity of wild type p53, but did not repress the activity of wild type p53 in SNU C2A cells owing to dominant activity of wild type. These cell condition may provide new gene therapeutic implications leading effective antiproliferation of cell when mutant and wild-type p53 protein were co-expressed in cell.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.208-216
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• 2004

Purpose: DNA-dependent protein kinase (DNA-PK) is a serine/threonine kinase consisting of a 470 kDa catalytic subunit (DNA-PKcs) and a heterodimeric regulatory complex, called Ku, which is composed of 70 kDa(Ku 70) and 86 kDa (Ku 80) proteins. The DNA-PK has been shown to play a pivotal role in rejoining DNA double-strand-breaks (dsb) in mammalian cells. The purpose of this study is to examine the relationship between the level of Ku expression and radiation sensitivity. Methods and Materials: Nine head and neck, cancer cell lines showed various intrinsic radiation sensitivities. Among the nine, AMC-HN-3 cell was the most sensitive for X-ray irradiation and AMC-HN-9 cell was the most resistance. The most sensitive and resistant cell lines were selected and the test sensitivity of radiation and expression of Ku were measured. Radiation sensitivity was obtained by colony forming assay and Ku protein expression using Western blot analysis. Results: Ku80 increased expression by radiation, wheres Ku70 did not. Overexpression of Ku80 protein increased radiation resistance in AMC-HN9 cell line. There was a correlation between Ku8O expression and radiation resistance. Ku80 was shown to play an important role in radiation damage response. Conclusion: Induction of Ku80 expression had an important role in DNA damage repair by radiation. Ku80 expression may be an effective predictive assay of radiosensitivity on head and neck cancer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.151-157
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• 2015

Recent laboratory studies have documented that mixotrophic dinoflagellates Dinophysis spp. and heterotrophic dinoflagellate Oxyphysis oxytoxoides share a common prey, i.e. the mixotrophic ciliate Mesodinium rubrum. Nonetheless, very little is known about the population dynamics and species interactions among these protists in natural environments. To investigate the interactions between the dinoflagellate predators and their ciliate prey in the field, we took the samples twice a day from 26 July to 28 August, 2011 at a fixed station in Masan Bay and analyzed their abundances. During this study, salinity was highly variable, ranging from 5 to 28, due to the periodic input of rainfalls to the sampling station. Water temperature was on average $26.5^{\circ}C$ until 20 August and thereafter was about $21^{\circ}C$ by the end of the sampling period. The ciliate M. rubrum occurred persistently throughout the sampling period, ranging from 13 to $492\;cells\;mL^{-1}$. Cell densities of D. acuminata and O. oxytoxoides ranged from undetectable level to $19,833\;cells\;L^{-1}$ and from undetectable level to $100,333\;cells\;L^{-1}$, respectively. The high abundance of D. acuminata mostly followed the blooming of the ciliate M. rubrum, but it often did not peak even during heavy blooms of the prey, probably due to sensitivity to large salinity fluctuation and also presumably overlapped grazing by other mixotrophic dinoflagellates. The abundance of O. oxytoxoides was detected only when water temperature was lower than $24^{\circ}C$, indicating that water temperature is an important environmental factor to control the population dynamics of the dinoflagellate species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.35-41
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• 2003

The study was conducted to develope a rapid method for the detection of Yersinia enterocolitica in spring water and vegetables via multiplex polymerase chain reaction (PCR) technique using ail, yst, uirF and subgenus-specific Y16S primers. Specificity and sensitivity of multiplex PCR and application of best primers for the detection of Y. enterocolitica from spring water and vegetables were investigeted. Y. enterocolitica ATCC 27729 strains gave 356 bP and 200 bp (Y16S) and 134 bp (yst) bands. but Y. enterocolitica ATCC 9610 and ATCC 23715 strains gave 200 bp and 134 bp bands.In the meanwhile, non-pathogenic Yersinia species, such as Y. frederikseni, Y. inter-media, Y. kristenseni and Y. pseudotuberculosis gave only single 200 bp band, and other bacteria including Escherichia coli O157:H7 ATCC 25392, Shigella dysenteri. Staphylococcu aureus ATCC 25923 and Listeria mo-nocytogenes ATCC 19111 did not show any bands. Among primers, yst and Y16S primer showed the best sensitivity. Seven CFU/mL Y. enterocolitica cells could be detected with yst and Y16S primers and the sensitivity was significantly improved by the further 2nd PCR after 38 cycles of first PCR amplication. Spring water, cabbage and mushroom were inoculated with Y. enterocolitica to determine the sensitivity of multiplex-PCR for the rapid detection of Y. enterocolitica. Multiplex-PCR assay could detect 7 or 70 cells in spring water and vegetables using whole cell lysate with repeating PCR amplication.

• Tuberculosis and Respiratory Diseases
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• v.68 no.2
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• pp.87-92
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• 2010

Background: D-dimer testing is widely applied as a first step in the diagnostic work-up of pulmonary embolism (PE). Although this is the most sensitive assay for ruling out PE, the prognostic implications of D-dimer testing in patients with normotensive PE are not well known. The aim of this study was to determine if D-dimer testing on admission predicts major adverse cardiac events (MACE) in patients with normotensive PE. Methods: A total of 180 consecutive patients with normotensive PE admitted between January 2003 and June 2009 were included. The group was divided into quartiles on the basis of their D-dimer levels. We compared the frequency of MACE by quartile of D-dimer level and estimated sensitivity, specificity, and predictive values for MACE in the first and fourth quartile. Results: In the 37 (20.6%) patients with MACEs, the median D-dimer level (7.94[IQR:4.03~18.17]${\mu}g/mL$) was higher than in patients with a benign course (5.29[IQR:2.60~11.52]${\mu}g/mL$, p<0.01). The occurrence of MACEs was increased with increasing D-dimer level (p=0.017). In the first quartile (D-Dimer <$2.76{\mu}g/mL$) sensitivity, specificity, and positive and negative predictive values for predicting MACEs were, respectively, 91.9%, 29.4%, 25.2%, and 93.3%. Conclusion: Patients with D-dimer levels below $2.76{\mu}g/mL$ have a low risk of MACEs. Our study suggest that D-dimer level may be used to identify low risk patients with normotensive PE.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.50-60
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• 1987

Sensitivity, expressed in the $96h-LC_{50}$ determined with continuous flow system, was compared for eight developmental stages of Oryzias latipes with butachlor, diazinon and fenitrothion. Significance of the laboratory determined $96h-LC_{50}$ in real field situation was evaluated for butachlor using outdoor model agrosystem. In the laboratory tests, the most sensitive stage was post-larva stage IV(7 days after hatching) with $96h-LC_{50}$ of 0.14, 1.4, and 1.6ppm for butachlor, diazinon and fenitrothion, respectively, whereas the least sensitive stage was early embryo stage(1 day after fertilization), and then the susceptibility was somewhat stable after 21days after hatching. In the model agrosystem test, the highest concentration of 0.53ppm of butachlor in water was obtained at the 2nd day after application. The stages IV and VIII showed mortality of over 50% at 96 hours after application. It is concluded that the conventional use of butachlor in the field would cause significant adverse effect on O. latipes. It is suggested that sensitivity test at the early life stages with fish is an important part of the ecotoxicological assessment of chemicals.

• Analytical Science and Technology
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• v.35 no.5
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• pp.205-211
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• 2022

Deuterium (D) is an isotope with one more neutron number than hydrogen (H). Heavy elements rarely change their chemical properties with little effect even if the number of neutrons increases, but low-mass elements change their vibration energy, diffusion rate, and reaction rate because the effect cannot be ignored, which is called an isotope effect. Recently, in the semiconductor and display industries, there is a trend to replace hydrogen gas (H₂) with deuterium gas (D₂) in order to improve process stability and product quality by using the isotope effect. In addition, as the demand for D₂ in industries increases, domestic gas producers are making efforts to produce and supply D₂ on their own. In the case of high purity D₂, most of them are produced by electrolysis of heavy water (D₂O), and among D₂, hydrogen deuteride (HD) molecules are present as isotope impurities. Therefore, in order to maximize the isotope effect of hydrogen in the electronic industry, HD, which is an isotope impurity of D₂ used in the process, should be small amount. To this end, purity analysis of D₂ for industrial processing is essential. In this study, HD quantitative analysis of D₂ for high purity D₂ purity analysis was established and hydrogen isotope RM (Reference material) was developed. Since hydrogen isotopes are difficult to analyze with general gas analysis instrument, they were analyzed using a high-precision mass spectrometer (Gas/MS, Finnigan MAT271). High purity HD gas was injected into Gas/MS, sensitivity was determined by a signal according to pressure, and HD concentrations in two bottles of D₂ were quantified using the corresponding sensitivity. The amount fraction of HD in each D₂ was (4518 ± 275) μmol/mol, (2282 ± 144) μmol/mol. D₂, which quantifies HD amount using the developed quantitative analysis method, will be manufactured with hydrogen isotope RM and distributed for quality management and maintenance of electronic industries and gas producers in the future.