• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.587-592
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• 1999

Littorina brevicula, a common small herbivorous gastropod, inhabits in almost every rocky and/or boulder shores of Korea with high density. The survival rates and oxygen consumption rates of this species exposed to tributyltinchloride (TBTCl), mercury (Hg) and cadmium (Cd) were investigated according to temperatures (15, $23^{\circ}C$) and individual sizes (12$\pm$0.5, 5$\pm$1 mm). At temperature $15^{\circ}C$, acute inhibitory concentrations for large (12$\pm$0.5 mm) and small (5 $\pm$1 mm) size individual showed that 13 day-$LC_{50}$ for TBTC1 were 0.87 and 0.65 ppm, respectively, 11 day-$LC_{50}$ of Hg were 5.55 and 2.85 ppm, respectively and 9 day-$LC_{50}$ of Cd were 13.77 and 8.46 ppm, respectively. At $23^{\circ}C$, acute inhibitory concentrations of pollutants on the large and the small size individual showed that 8 day-$LC_{50}$ of TBTCl were 0.68 and 0.15 ppm, respectively, 5 day-$LC_{50}$ of Hg were 10.41 and 5.73 ppm, respectively, and 4 day-$LC_{50}$ of Cd were 13.31 and 4.47 ppm, respectively. The order of toxicity on the species was TBTCl > Cd > Hg. Oxygen consumption rates during exposure to TBTCl, Hg and Cd toxicity were decreased more in small size than in large size individuals at 15 and $23^{\circ}C$.

• Journal of Haehwa Medicine
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• v.17 no.1
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• pp.83-93
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• 2008

In order to study the Effects of yindong(LC) on the variation of blood and joint value the gout induced by microcrystalline sodium urate in rats, for LC is one of the important medicine on gout. After pretreatment of LC(50, 500mg/kg) for 5days, the Effects of LC was evaluated on Serum albumin, Serum globulin, glutamate dxalacetate transminase(AST), glutanate pyruvate transminase(ALT), blood urea nitrogen(BUN), Serum creatitine, Serum uric acid, xanthine oxidase activity, Erythrocyte Sedimentation Rate(ESR), WBC, platelet were measured. The results were obtained as follows : Joint value Increase ratio was not significantly decreased in all LC taken groups compared with the control group. Serum albumin was significantly different in all LC taken groups compared with the control group and Serum globulin was significantly dicreased in 500mg/kgLC taken group compared with the control group. Serum AST, ALT were significantly dicreased in 500mg/kgLC taken group compared with the control group. Serum BUN was significantly decreased in all LC taken groups and Serum creatinine was significantly decreased in 500mg/kgLC taken group compared with the control group. Serum uric acid was significantly different in 500mg/kgLC taken group, and changes in xanthine oxidase activity was significantly decreased in 500mg/kg, 50mg/kgLC taken group. ESR was significantly decreased in all LC taken groups compared with the control group. WBC, platelet count were significantly decreased in 500mg/kgLC taken group compared with the control group. From above results it may be concluded that Yindong can be used for treatment and preventive medcine of gout induced by microcrystalline sodium urate in clinic.

• Fibers and Polymers
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• v.2 no.3
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• pp.129-134
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• 2001

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) (50/50, mole/mole) [PECPT] was synthesized and blended with polycarbonate (PC). LC properties of PECPT and thermal, morphological, and rheological behaviors of the PECPT/PC blend were studied. PECPT showed the nematic LC phase and much longer relaxation time than poly(ethylene terephthalate) (PET). The apparent melt viscosity of PECPT was one third of that of FET. An abrupt torque change was observed during the blending process due to the orientation of LC domains. For the blends containing 10~30 wt% of PECPT, the complex viscosities were higher than that of PC. As PECPT content increases above 40 wt%, shear thinning was observed. The lowest complex viscosity was obtained at 40~50 wt%. Transesterification of PECPT and PC was confirmed by the selective chemical degradation of carbonate groups in PC.

• Korean Journal of Veterinary Service
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• v.25 no.3
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• pp.221-227
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• 2002

This study was carried out to confirm analytical method of residual macrolides in livestock products by LC/MS. 1. Macrolides were analyzed by LC/MS on XTerra C$\sub$18/ column with 0.1% TFA(trifluoroacetic acid)-methanol in a gradient mode as mobile phase, and that were identified by positive chemical ionization with selective ion monitoring at 50～1000 mass range. 2. Residual macrolides were extracted from tissue with acetonitrile, and the extract is purified with a Sep-pak C$\sub$18/ cartridge, and elute macrolides with 0.1M methanolic ammonium acetate. 3. The procedure confirms the presence of each macrolide at 50$\mu\textrm{g}$/kg in spiked sample.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.43-50
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• 2001

The IP routing uses the longest-matching prefix to determine the destination. Fast lookup should be required for the high speed routing. We propose a modified LC-trie, called multiple LC-trie, which is suitable data structure for fast address-lookups in software implementation. To reduce the number of memory accesses, our scheme analyzes the distribution of IP address access pattern, and constructs multiple LC:-tries for frequently accessed IP addresses. Our experimental results show that our scheme can perform faster than the original LC-trie schemes.

• Korean Journal of Optics and Photonics
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• v.12 no.4
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• pp.276-280
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• 2001

The quality of images displayed by using an LC projector is strongly influenced by the cell-gap variations over LC panels, the essential components of the projector. We show that such influence can be relieved by introducing slit patterns in the pixel electrodes in the LC panels. The improvement comes from the compensation of the influence of cell-gap variations by optical anisotropy variations arising from the lateral components of the electric field generated by the slit patterned electrodes. Simulations show that cell-gap tolerance can be increased by more than 50% by introducing the slit patterns. This method can be used in TN mode LC panels, which use LC's with positive dielectric anisotropy. tropy.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.3
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• pp.311-320
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• 2008

In this paper, a new variable active inductor using a conventional grounded active inductor with feedback variable LC-resonator is proposed. The grounded active inductor is realized by the gyrator-C topology and the variable LC-resonator is realized by the low-Q spiral inductor and varactor. This variable LC-resonator can compensate the degradation of Q-factor due to parasitic capacitance of a transistor, and the frequency range with high Q-factor is adjustable by resonance frequency adjustment of LC-resonator. The fabricated variable active inductor with Magnachip $0.18{\mu}m$ CMOS process shows that high-Q frequency range can be adjusted according to varactor control voltage from 4.66 GHz to 5.45 GHz and Q-factor is higher than 50 in the operating frequency ranges. The measured inductance at 4.9GHz can be controlled from 4.12 nH to 5.97 nH by control voltage.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.99-106
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• 1998

This study was performed to investigate the bioconcentration of dichlorvos, methidathion and phosalone in zebrafish (brachydanio rerio), red sword tail(Xiphophorus hellieri). The fishes were exposed to 0.05 ppm, 0.01 ppm, 0.50 ppm, one-hundredth concentration of 96-hrs LC$_{50}$ and one-thousandth concentration of 96-hrs LC$_{50}$ and test periods were 3, 5 and 8 days. The deputation rate of each pesticide from the whole body of fish was determined over the 24-hr period after treatment. Obtained results are summerized as follows: In the case of dichlorvos, dichlorvos concentration in zebrafish extract and BCF$_{s}$ of dichlorvos were increased as increasing test concentration. In the case of same experimental concentrations, dichlorvos concentration in zebrafish extract and BCF$_{s}$ of dichlorvos were decreased as proloning test periods, especially dropped after 5days. Dichlorvos concentration in red sword tail extract were increased as increasing test concentration, lyat BCF$_{s}$ in concentration of 0.05 ppm, 0.01 ppm and one-hundredth of 96-hrs LC$_{50}$ were decreased. Methidathion and phosalone concentration in zebrafish extract in zebrafish extract were increased as increasing test concentration, but there was little difference in BCF$_{s}$. In the case of same experimental concentrations, there were little differences in BCF$_{s}$ and concentration in zebrafish extract. In the case of red sword tail, it was impossible to calculate on BCF$_{s}$ data because test concentration was under the detecting limit on GC or test fish were die. Determined deputation rate conatant were highest on dichlorvos, and followed by methidathion, and phosalone. The results of determining depuration rate of these pesticides showed that the high BCF in fish might be due to the slow depuration rate in fish, it is thought to be responsible for vapor pressure, water solubility and partition coefficient. It is suggested that one-hundredth concentration of 96-hrs LC$_{50}$ will be proper test concentration because one-thousundth of LC$_{50}$ was under the detecting limit on GC. Dichlorvos, methidathion and phosalone, organophosphorous pesticides, were examined to their BCF$_{s}$ and depuration rates by means of fish test.

• Journal of fish pathology
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• v.22 no.1
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• pp.1-7
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• 2009

To investigate the effect of hydrogen peroxide in israel carp, Cyprinus carpio, toxicity and microbial activities were determined. For hydrogen peroxide toxicity test, the median lethal concentration ($LC_{50}$) to israel carps Cyprinus carpio (average weight 0.44 g) by acute toxicity was determined after 24 hour treatment. All israel carp were alive in 24 hours treatment at 80 $\mu\ell/\ell$ concentration and $LC_{50}$ value was 148.9 $\mu\ell/\ell$. For biocidal activities of hydrogen peroxide, remove of parasite and growth inhibition of pathogenic bacteria were determined. The parasite Trichodina sp. infected on the skin and gills of israel carps (average weight 0.1 g) was completely eliminated at 40 $\mu\ell/\ell$ of hydrogen peroxide treatment for 24 hour. Most of the minimum inhibitory concentrations (MICs) against 30 fish pathogenic bacteria were less than 40 $\mu\ell/\ell$.

• Microbiology and Biotechnology Letters
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• v.13 no.2
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• pp.157-162
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• 1985

The cell cultures and crude extracts of Bacillus sphaericus 1593 K-5 and its mutant Spo-Dl216 were respectively bioassayed against Culex pipiens var. pollens mosquito larvae. The B. sphaeriucs 1593 K-5 showed toxic activity against the larvae. LC$_{50}$ values (cells/$m\ell$) was 2.6$\times$10$^2$. Also the LC$_{50}$ ($\mu\textrm{g}$ Protein/$m\ell$) of the crude extract was 10.26. However, B. sphaericus Spo-Dl216 didn't show toxic activity against the larvae. The soluble cytoplasmic toxin in broken B. sphaeriucs 1593k-5 cells was partially purified by gel permeation chromatography and ion exchange chromatography. Among the fractions of the gel permeation chromatography only a single fraction was found to be toxic. LC$_{50}$ values ($\mu\textrm{g}$ protein/$m\ell$) of the active fraction was 0.182. The active fraction of the gel permeation was subjected to ion exchange chromatography. Only a single fraction showed toxic activity and its LC$_{50}$ values ($\mu\textrm{g}$ protein/$m\ell$) was 0.02..02.