• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.229-238
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• 1977

Sumithion and EPN residues on grapes, EPN and Diazinon on chinese cabbage, Parathion on peaches, Dimethoate on tomatoes, and EPN and Malathion on cucumber were analyzed in terms of 0, 3, 7, 14, 21 and 30 days after last application for the pesticides safty use. From the disappearance rate for various organo-phosphate insecticides on vegetables and fruit crops, following results are obtained. 1. On Chinese cabbage, Diazinon residues were 0.25~0.38p.p.m three weeks after one application, and EPN were 1.39~2.69p.p.m seven days after one application and 0.96~2.34p.p.m two weeks after twice application. 2. EPN residues on grapes were 1.09~1.80p.p.m seven days after one application and Sumithion were 0.17~0.53p.p.m fourteen days after one application. 3. On peaches, Parathion residues were 0.40~0.61p.p.m two weeks after last application. 4. Dimethoate residues on tomatoes were 0.141p.p.m seven days after four times application. 5. On cucumber, EPN residues were 2.11~2.14p.p.m three days after twice application, and Malathion were 0.46p.p.m 3 day after four times application but 0.062~0.025p.p.m three days after last application. 6. Rate of degradation of organo-phosphate chemicals is inversely related to half-life of its. 7. Minimum intervals between last treatment and harvest to prevent unsafty residues are as follows. 7 days for EPN with one application and 14 days with twice application on chinese cabbage, 3 days on cucumber and 7 days on grape, 14 days for parathion, 7 days for dimethoate on tomatoes, 0 to 3 days for Malathion on cucumber, 21 days for Sumithion on grape, 21 days on chinese cabbage for Diazinon.

• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.213-217
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• 2018

Tolaasin secreted by Pseudomonas tolaasii is a peptide toxin and causes brown blotch disease on the cultivated mushrooms by collapsing cellular and fruiting body structure. Toxicity of tolaasin was evaluated by measuring hemolytic activity because tolaasin molecules form membrane pores on the red blood cells and destroy cell membrane structure. In the previous studies, we found that tolaasin cytotoxicity was suppressed by $Zn^{2+}$ and $Ni^{2+}$. $Ni^{2+}$ inhibited the tolaasin-induced hemolysis in a dose-dependent manner and its $K_i$ value was 1.8 mM. The hemolytic activity was completely inhibited at the concentration higher than 10 mM. The inhibitory effect of $Zn^{2+}$ on tolaasin-induced hemolysis was increased in alkaline pH, while that of $Ni^{2+}$was not much dependent on pH. When the pH of buffer solution was increased from pH 7 to pH 9, the time for 50% hemolysis ($T_{50}$) was increased greatly by $100{\mu}M$ $Zn^{2+}$; however, it was slightly increased by 1 mM $Ni^{2+}$ at all pH values. When the synergistic effect of $Zn^{2+}$ and $Ni^{2+}$ on tolaasin-induced hemolysis was measured, it was not dependent on the pH of buffer solution. Molecular elucidation of the difference in pH-dependence of these two metal ions may contribute to understand the mechanism of tolaasin pore formation and cytotoxicity.

• Korean Journal of Microbiology
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• v.23 no.3
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• pp.177-183
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• 1985

Some properties of an extracellular cytosine deaminase produced from Arthrobacter sp.JH-13 were examined after 20-80% of ammonium sulfate fractionation. Among some substrates, this enzyme utilized cytosine and 5-fluorocytosine as a substrate. The optimum pH and temperature for the activity of this enzyme were found to be near 8.0 and $40^{\circ}C$, respectively. The ensyme was more stable in 0.2M of Tris-HCl buffer than 0.2M of potassium phosphate buffer. The enzyme was generally stable below $50^{\circ}C$, but inactivated completely at $70^{\circ}C$. 1mM of $Fe^{3+},\;K^+\;and\;Na^+$ increased the enzyme activity, but 0.01mM of $Co^{2+},\;Cu^{2+},\;Ni^{2+},\;Hg^{2+},\;Ag^{2+},\;Zn^{2+},\;Ba^{2+},\;and\;Mg^{2+}$ markedly inactivated the enzyme activity. 0.1mM of p-chloromercuribenzoate, trichloroacetic acid, and N-ethylmaleimide compleyely inhibited the enzyme activity, but 0.1mM of 2-mercaptoethanol slightly increased the enzyme activity.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.117-124
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• 1991

Soybean plants inoculated with Bradyrhizobium japonicum MN 110 were supplied with nutrient solutions containing 1.0, 0.25 and 0.5.nM-P to characterize the effect of externaI-P supply on the phosphorus status of nodules and on the P-uptake system of isolated bacteroids from nodules. After 48 days of growth, whole plant dry mass in the 0.25 and 0.05 mM-P treatments decreased significantly. The Pi concentrations in nodules were 4.1, 2.5 and 2.0 mM for 1.0, 0.25 and 0.05 mM-P treatments, respectively. The external-P supply did not significantly affect the distribution of phosphorus among inorganic phosphate(Pi), soluble organic-phosphorus(SOP) and insoluble organic-phosphorus(TOP) fractions in nodules. The Pi concentrations in young leaves of 0.25 and 0.05 mM-P plants were 33% and 20% , respectively, of those in young leaves of 1.0 mM-P plants and Pi concentrations in old leaves were only 16% and 7%, respectively, of those in old leaves of 1.0 mM-P plants. Phosphorus deficiency decreased the percentage of total leaf phosphorus in the Pi fraction and increased the percentage of total leaf phosphorus in the IOP fraction. The bacteroid number ranged from 0.87 to $1.30{\times}10^{11}$ Per GFW nodule regardless of external-P supply to the host Plants and Plant age, The P-uptake rates were the same (15-16 pmoles /min./$10^8$ bacteroids) for the bacteroids isolated from nodules of 1.0 mM-P and 0.05 mM-P plants. These results indicate that Pi concentrations in nodules of phosphorus-deficient plants are sufficient for proliferation of bacteroids and that the P-uptake system of bacteroids is in a repressed state even when host plant growth is severely restricted by phosphorus-deficiency stress.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.345-346
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• 2006

In the future, a machine will be more improved in the form of advanced concept with collaborative ability in M2M(Machine to Machine, Mobile to Machine) environment for u-Manufacturing system. This paper tried to standardize M2M and design advanced concept machine. The M2M is front-end system for implementing autonomous ubiquitous environment. The advanced machine in M2M will be a collaborative machine with knowledge-evolutionary ability such as u-Machine(Ubiquitous machine), Vortal(Vertical Portal) machine and P2P(Peer to Peer) machine. Such advanced concept machines will be the key subject for M2M cooperation.

• Journal of applied mathematics & informatics
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• v.40 no.5_6
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• pp.1181-1198
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• 2022

In this paper we are concerned with the number of fuzzy subgroups of a finite abelian p-group ℤ_p^m × ℤ_pⁿ × ℤ_p^ℓ of rank three with order p^m+n+ℓ. We obtain a recurrence relation for the number of fuzzy subgroups of a finite abelian p-group ℤ_p^m × ℤ_pⁿ × ℤ_p^ℓ. In order to show that using this recurrence relation, one can find explicit formulas for the number of fuzzy subgroups of ℤ_p^m × ℤ_pⁿ × ℤ_p^ℓ consecutively, we give explicit formulas for the number of fuzzy subgroups of ℤ_p^m × ℤ_pⁿ × ℤ_p^ℓ where (n, ℓ) = (1, 1), (2, 1), (3, 1), (4, 1), (5, 1), (2, 2), (3, 2), (4, 2), (5, 2).

• Microbiology and Biotechnology Letters
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• v.24 no.5
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• pp.613-618
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• 1996

Microorganisms capable of producing ascorbic acid-2-phosphate (AsA2P) from ascorbic acid (AsA) and pyrophosphate (PPi) were screened from the culture collection of this laboratory. Among them, Cellulomonas sp. AP-7 showed the highest productivity of AsA2P. The optimal conditions for the production of AsA2P from AsA and PPi with cell-free extract as an enzyme source were investigated. The reaction mixture for the maximal production of AsA2P consisted of 21 g protein of cell-free extract per liter as the enzyme source, 250 mM AsA, 200 mM sodium pyrophosphate, 150 mM sodium acetate buffer (pH 4.5). By using this reaction mixture, 31.9 mM of AsA2P, which corresponded to a 12.76% yield based on AsA, was produced after incubation of 48 hr at 33$\circ$C.

• Bulletin of the Korean Mathematical Society
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• v.57 no.2
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• pp.429-441
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• 2020

Let M(X, Y) denote the space of multipliers from X to Y, where X and Y are analytic function spaces. As we known, for Dirichlet-type spaces 𝓓_α^p, M(𝓓_p-1^p, 𝓓_q-1^q) = {0}, if p ≠ q, 0 < p, q < ∞. If 0 < p, q < ∞, p ≠ q, 0 < s < 1 such that p + s, q + s > 1, then M(𝓓_p-2+s^p, 𝓓_q-2+s^q) = {0}. However, X ∩ 𝓓_p-1^p ⊆ X ∩ 𝓓_q-1^q and X ∩ 𝓓_p-2+s^p ⊆ X ∩ 𝓓_q-2+s^p whenever X is a subspace of the Bloch space 𝓑 and 0 < p ≤ q < ∞. This says that the set of multipliers M(X ∩ 𝓓 _p-2+s^p, X∩𝓓_q-2+s^q) is nontrivial. In this paper, we study the multipliers M(X ∩ 𝓓_p-2+s^p, X ∩ 𝓓_q-2+s^q) for distinct classical subspaces X of the Bloch space 𝓑, where X = 𝓑, BMOA or 𝓗^∞.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.149-154
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• 2007

In the present study, we performed the PCR assay using TOX2P/TOX2M primer targeting a specific region within mcyB gene to identify potential microcystin-producing cyanobacteria. TOX2P/TOX2M primer set was effective in amplifying mcy gene in the field samples containing Microcystis spp. of 1,000 cells per mL. Moreover, the results from the PCR assay agreed with those of the ELISA analysis. Consequently, this study demonstrated that TOX2P/TOX2M primer set can be used as a genetic probe for the early detection of cyanobacterial toxigenicity in Korean water bodies.

• Development and Reproduction
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• v.15 no.3
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• pp.223-230
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• 2011

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants derived from incomplete combustion of carbons and crude oil. In this study, we investigated the effects of benzo[a]pyrene (B[a]P), a representative PAHs on in vitro sex steroid hormone production and germinal vesicle breakdown (GVBD) using isolated oocytes of longchin goby (Chasmichthys dolichognathus) and chameleon goby (Tridentiger trigonocephalus). Oocytes in diameters of 0.8-0.9 (end vitellogenic stage) and 0.9-1.0 mm (germinal vesicle migratory stage) from longchin goby and 0.5 mm (fully vitellogenic stage) from chameleon goby were used. In GVBD assay, B[a]P at 10 nM stimulated GVBD in the oocytes of 0.8-0.9 mm from longchin goby. B[a]P at 1 nM stimulated GVBD in the oocytes with diameter 0.5 mm from chameleon goby. In steroid production from oocytes of longchin goby, B[a]P at 100 nM decreased testosterone (T) production, B[a]P at 1,000 nM increased estraiol-17 (J (E2) production and 10 and 100 nM increased $17,20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$) production in the oocytes with diameter 0.8-0.9 mm. B[a]P at 1,000 nM increased E2 production, 100 and 1,000 nM increased $17{\alpha}20{\beta}P$ production in the oocytes with diameter 0.9-1.0 mm. In steroid production of oocytes from chameleon goby, B[a]P at 1,000 nM increased $E_2$ production. B[a]P at 10 nM increased $17{\alpha}20{\beta}P$ production. In the ratio of $E_2$ to T ($E_2$/T), B[a]P at 100 and 1,000 nM increased $E_2$/T in the oocytes of longchin goby. B[a]P at 100 nM also increased $E_2$/T in the oocytes of chameleon goby. Taken together, these results suggest that B[a]P have not only weak estrogenic effects but progestogenic effects on oocyte maturation.