• Korean Journal of Veterinary Service
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• v.14 no.1
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• pp.71-77
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• 1991

Parathion is widely used in agriculture, but it is highly toxic and now clear that parathion behaves like a cholinergic drug by inhibiting the enzyme cholinesterase. In order to know acute toxicity and the changes of cholinesterase activity according to time lapsed in Sprague-Dawley rats injected single with half dose to LD$_{50}$ of parathion, cholinesterase activities in serum, spinal cord, whole brain and median lethal dose between sex difference were investigated. The results obtained were summerized as follows ; 1. 4LD_{50}$ values of parathion given intraperitoneally to male and female rats were 10.5mg / kg(95% confidence limits, 6.6-16.8mg/ kg) and 3.3mg/ kg(95% confidence limits, 1.9-5.6mg/ kg). 2. The inhibition rate of cholinesterase activities in serum of parathion-injected rats according to time lapsed were peakly decreased to 35.4%(male) and 32.4%(female) after 1 hour in comparison to control group, but cholinesterase activities were completely recovered after 48 hours. 3. The inhibition rate of cholinesterase activities in spinal cord of parathion-injected rats according to time lapsed were peakly decreased to 31.1% (male) and 36.3% (female) after 30 minutes in comparison to control group, but cholinesterase activities were completely recovered after 48 hours. 4. The inhibition rate of cholinesterase activities in whole brain of parathion -injected rats according to time lapsed were peakly decreased to 32.2%(male) and 42.6%(female) after 1 hour in comparison to control group, but cholinesterase activities were completely recovered after 48 hours.s.

• ALGAE
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• v.20 no.4
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• pp.379-388
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• 2005

Seagrass bed is an important component in coastal and estuarine ecosystems, providing food and shelter to a wide variety of fauna. Recently, seagrass coverage has declined significantly due to anthropogenic influences such as reclamation, dredging, and eutrophication and consequently, necessity of seagrass habitat restoration is rising. Transplantation experiments with Zostera marina using TERFS, staple method, and shell method have been conducted at Dadae Bay, Kosung Bay and Jindong Bay on the south coast of Korea to select an optimal transplanting method for restoration of Z. marina habitat. Three experimental sites located at the vicinity of natural Z. marina beds with an average water depth of about 4m. Z. marina plants, which were collected from donor bed in Koje Bay were also transplanted at 7 different time from October 2003 to July 2004 to find appropriate transplanting time. Density of Z. marina was monitored monthly at both transplanted areas and natural beds. Transplantation using the staple method showed the highest survival rate of transplant. Shell method was also an effective transplanting method at muddy areas in Kosung Bay and Jindong Bay, but not suitable at sandy areas in Dadae Bay. These results suggest that sediment composition of transplanting areas should be considered for the selection of the optimal transplanting method. Z. marina transplanted during fall usually showed the highest survival rate, while most Z. marina plants transplanted in summer died due to high lethal temperature during this period.

• Journal of Pharmacopuncture
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• v.18 no.4
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• pp.7-11
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• 2015

Objectives: Bee venom (BV) is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera) on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Methods: Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50), and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Blood samples were obtained from 10 rabbits, and the prothrombin time (PT) and the partial thromboplastin time (PTT) tests were conducted. The approximate lethal dose (LD) values of BV were determined. Results: Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations $(SDs)={\pm}0.71$; however, clotting was observed in the control group 13.8 s, $SDs={\pm}0.52$. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa), respectively. The $LD_{50}$ of the crude BV was found to be $177.8{\mu}g/mouse$. Conclusion: BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase $A_2(PLA_2)$ and melittin, and that can increase the blood clotting times in vitro.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.1-11
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• 1988

Recovery from potentially lethal damage (PLDR) after irradiation was studied in plateau-phase culture of Vero cells in vitro. Unfed plateau-phase cells were irradiated with dose of 1 to 9Gy using Cs-137 irradiator. Cells then were incubated again and left in situ for 0, 1, 2, 3, 4, 5, 6, and 24 hours and then were trypsinized explanted, and subcultured in fresh RPMI-1640 media containing $0.33\%$ agar. Cell survival was measured by colony forming ability. An adequate number of heavily irradiated Vero cells were added as feeder cells to make the total cell number constant in every culture dish. As the postirradiation in situ incubation time increased, surviving fraction increased by PLDR. The rate of PLDR was so rapid that increased surviving fraction reached saturation level at 2 to 4 hours after in situ incubation. As the radiation dose increased, the rate of PLDR fastened and the magnitude of increased surviving fraction at saturation level by PLOR also increased. In analysis of cell survival curve fitted to the linear-quadratic model, the linear inactivation coefficient $(\alpha)$ decreased largely and reached nearly to zero but the quadratic inactivation coefficient $(\beta)$ increased minimally by increment of postirradiation in situ incubation time. So PLDR mainly affected the damage expressed as $\alpha$, In the multitarget model, significant change was not obtained in $D_0\;but\;in D_q$. Therefore, shoulder region in cell survival curve was mainly affected by PLDR and terminal slope was not influenced at all. And dose-modifying factor by PLDR was relatively higher in shoulder region, that is, in low dose area below 3 Gy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.520-528
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• 1992

In order to establish the standard conditions for thermal sterilization of foods, a microcomputer based $F_o-value$ measuring system was developed upon the basis of the time-temperature profile in food. $F_o-value$ was calculated simultaneously from the time-temperature profile, and described as integrated lethality during the whole sterilization process. The accuracy of system was evaluated by the analysis of thermal diffusivity of the model solid food, Alaska pollack surimi. The $F_o-value$ could be measured precisely under the different sterilizing conditions as the varied time and temperature. The practical thermal diffusivities from various sterilizing conditions agreed well to the values predicted by some experimental equations suggested in the literatures. The differences were within the range of $\pm12\%$.

• Progress in Medical Physics
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• v.5 no.2
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• pp.35-43
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• 1994

Electromagnetic wave may induce effect and damage on the bio-body, either by electric fields of magnetic fields. We measure electrophysiological changs in rabbit's brain exposed to 2.45GHz micro wave(power density 40mW/cm$^2$) which distance 30cm from the source. In order to process the bio-electrical signal (EEG), used pre-amplifier module with self-made and Digtal analyzer computer system. Spectal analysis of the EEG showed variable power in the frequency range(1～30Hz) through each exposure time(10min, 20min, 30min) before and after. In effectively measured by the bio-electrical signal processing and can found threshold of minmal permissible exposure and lethal exposure.

• Korean Journal of Environmental Agriculture
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• v.15 no.2
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• pp.207-216
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• 1996

Simulated acid rain(SAR) treatment caused a lethal effect on the newly germinated seedlings of Capsicum annum cv. Komyung even though the germination rate of the seeds was stimulated by the treatment of SAR. Young germinated seedlings were much more sensitive to SAR than the already-grown seedlings. The typical symptom caused by SAR was white spot or lesion on the leaf and appeared readily and severely at the low pH of SAR. Generally, Phytophthora rot was severer in SAR treatments than in control. However, the disease was less severe in lower pH of the SAR treatment than in higher pH. Pathogen inoculation following the SAR treatment increased the disease. The severest Phytophthora rot was observed in the SAR treatment of pH 4.0 or 4.5 regardless of the inoculation time.

• Journal of Environmental Science International
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• v.7 no.4
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• pp.501-504
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• 1998

The role of iron as a possible pathogenic factor in the Infection of V. vulnificus was examined in thins paper The effects of iron and $CCl_4$ on the growth of V. vulnificus in human and rabbit sera were also done. Injection of iron to mice resulted in a lowering of the 50% lethal dose and in a reduction in the time of death postinfection. Serum iron levels were also elevated by damaged livers with infections of $CCl_4$- The inoculum size required to kill these mice was directly correlated with serum iron Irvels. Iron appeared to be the limiting factor In the ability of thins organism to survive or grow in mammalian sera. These results, both in vitro and In vivo, provided strong evidence that iron may play a major role In the pathogenesis of V. vulnificus.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.377-384
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• 2019

People currently spend more than 80% of their time indoors; therefore, the management of indoor air quality has become an important issue. The contamination of indoor air can cause sick house syndrome and various environmental diseases such as atopy and nephropathy. Formaldehyde gas, which is the main contaminant of indoor air, is lethal even with microscopic exposure; however, it is commonly used as an adhesive and waterproofing agent for indoor building materials. Therefore, there is a need for a gas sensor capable of detecting trace amounts of formaldehyde gas. In this review, we summarize recent studies on metal oxide-based semiconductor gas sensors for formaldehyde gas detection, methods to improve the gas-sensing properties of metal oxides of various dimensions, and the effects of catalysts for the detection of parts-per-billion level gases. Through this, we discuss the necessary characteristics of the metal oxidebased semiconductors for gas sensors for the development of next-generation sensors.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.3.1-3.6
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• 2015

Objectives This study aims to evaluate the size-dependent toxicity of spherical silver nanoparticles (Ag NPs) to an endemic benthic organism, Glyptotendipes tokunagai. Methods Ag nanoparticles of three nominal sizes (50, 100, and 150 nm) capped with polyvinyl pyrrolidone (PVP-Ag NPs) were used. Their physicochemical properties, acute toxicity (48 hours), and bioaccumulation were measured using third instar larvae of G. tokunagai. Results The aggregation and dissolution of PVP-Ag NPs increased with exposure time and concentration, respectively, particularly for 50 nm PVP-Ag NPs. However, the dissolved concentration of Ag ions was not significant compared with the median lethal concentration value for $AgNO_3$ (3.51 mg/L). The acute toxicity of PVP-Ag NPs was highest for the smallest particles (50 nm), whereas bioaccumulation was greatest for the largest particles (150 nm). However, larger PVP-Ag NPs were absorbed and excreted rapidly, resulting in shorter stays in G. tokunagai than the smaller ones. Conclusions The size of PVP-Ag NPs significantly affects their acute toxicity to G. tokunagai. In particular, smaller PVP-Ag NPs have a higher solubility and stay longer in the body of G. tokunagai, resulting in higher toxicity than larger PVP-Ag NPs.