• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.10-15
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• 2010

Most pesticides are poorly soluble in water and must be dissolved in a solvent carrier before being added to the test medium on aquatic toxicity test. The concentration of solvent is critical to the success of a test. This study were conducted to recommend possible organic solvents which have good solubility for pesticides and low toxicity to Korean native water flea to establish new standard toxicity test methods using Korean native water flea for ecological risk assessment of pesticide. Four Korean freshwater cladocerans, Daphnia obtusa, Daphnia sp., Moina macrocopa and Simocephalus vetulus were exposed to 10 different organic solvents during 48 hours to evaluate their toxic response to solvents. Ethyl acetate was the most toxic to cladocerans tested. Although ethyl ether was the least toxic to cladocerans tested, it may not adequate as possible solvent in aquatic toxicity test due to high volatility and low water solubility. In conclusion, acetone, methanol, ethanol and acetonitrile which has low toxicity as well as good water solubility are recommended as optimal organic solvent to use in aquatic toxicity tests with Korean native cladocerans tested.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.2
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• pp.131-134
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• 2010

Purpose: TOMO therapy treatment for a relatively long run Beam time and temperature-sensitive detector, such as CT clinics in optimal temperature ($20~21^{\circ}$) to maintain a constant temperature in addition to its own Chamber Cooling system is activating. TOMO This clinic has been reduced in the patients' body temperature to keep the sheets and covers over the treated area. Therefore, these materials for any changes in the organization gives the dose were analyzed. Materials and Methods: To compare changes in the organization Dose Phantom cheese (Cheese Phantom) were used, CT-simulation taking the center point of the cheese phantom PTV (Planning Target Volume, treatment planning target volume) by setting Daily dose 200 cGy, 3 meetings planned treatment. PTV, PTV +7 cm, PTV +14 cm, the total count points on the phantom using the Ion chamber cover without any substance to measure the dose, and one of the most commonly used treatment, including the frequently used four kinds of bedding materials (febric 0.8 mm, gown 1.4 mm, rug, 3.3 mm, blanket 13.7 mm) and covered with a phantom and the dose measured at the same location were analyzed 3 times each. Results: PTV, PTV +7 cm, PTV +14 cm from the point of any substance measured in the state are covered with four kinds of materials (fabric, gown, rug, blanket) was measured in the covered states and compares their results, PTV respectively -0.17%, -0.44%, -0.53% and -0.9% change, PTV +7 cm, respectively -0.04%, +0.07%, +0.06%, +0.07%, were changed, PTV +14 cm, respectively 0%, -0.06%, -0.02%, +0.6%, respectively. Conclusion: These results TOMO treatment to patients to maintain their body mass by using PTV thickness of the material decreased in proportion to. PTV +7 cm, but showed slight changes in the point, PTV +14 cm at the point of the dose was increased a little. Sejijeom all the difference in treatment tolerance ${\pm}3%$ range, this is confirmed in the coming treatment will not affect the larger should be considered.

• Journal of Environmental Impact Assessment
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• v.29 no.3
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• pp.157-181
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• 2020

Sediments from rivers, lakes and marine ports serve as end points for pollutants discharged into the water, and at the same time serve as sources of pollutants that are continuously released into the water. Until now, the contaminated sediments have been landfilled or dumped at sea. Landfilling, however, was expensive and dumping at sea was completely banned due to the London Convention. Therefore, this study applied contaminated sedimentation soil of 'Royal Palace Livestock Complex' as soil purification method. Soil remediation methods were applied to pretreatment, composting, soil washing, electrokinetics, and thermal desorption by selecting overseas application cases and domestically applicable application technologies. As a result of surveying the site for pollutant characteristics, Disolved Oxigen (DO), Suspended Solid (SS), Chemical Oxygen Demand (COD), Total Nitrogen (TN), and Total Phosphorus (TP) exceeded the discharged water quality standard, and especially SS, COD, TN, and TP exceeded the standard several tens to several hundred times. Soil showed high concentrations of copper and zinc, which promote the growth of pig feed, and cadmium exceeded 1 standard of Soil Environment Conservation Act. In the pretreatment technology, hydrocyclone was used for particle size separation, and the fine soil was separated by more than 80%. Composting was performed on organic and Total Petroleum Hydrocarbon (TPH) contaminated soils. TPH was treated within the standard of concern, and E. coli was analyzed to be high in organic matter, and the fertilizer specification was satisfied by applying the optimum composting conditions at 70℃, but the organic matter content was lower than the fertilizer specification. As a result of continuous washing test, Cd has 5 levels of residual material in fine soil. Cu and Zn were mostly composed of ion exchange properties (stage 1), carbonates (stage 2), and iron / manganese oxides (stage 3), which facilitate easy separation of contamination. As a result of applying acid dissolution and multi-stage washing step by step, hydrochloric acid, 1.0M, 1: 3, 200rpm, 60min was analyzed as the optimal washing factor. Most of the contaminated sediments were found to satisfy the Soil Environmental Conservation Act's standards. Therefore, as a result of the applicability test of this study, soil with high heavy metal contamination was used as aggregate by applying soil cleaning after pre-treatment. It was possible to verify that it was efficient to use organic and oil-contaminated soil as compost Maturity after exterminating contaminants and E. coli by applying composting.

• Journal of Life Science
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• v.19 no.6
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• pp.770-780
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• 2009

A new photosensitizer, 9-Hydroxypheophorbide-a (9-HpbD-a), was derived from Spirulina platensis. We conducted a series of experiments, in vitro and in vivo, to evaluate the anticancer effect and mechanism of photodynamic therapy using 9-HpbD-a and 660 nm diode lasers on a squamous carcinoma cell line. We studied the cytotoxic effects of pheophytin-a, 9-HpbD-a, 9-HpbD-a red and 660 nm diode lasers in a human head and neck cancer cell line (SNU-1041). Cell growth inhibition was determined by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The effects of 9-HpbD was higher than those of 9-HpbD-a red or pheophytin-a in PDT. We then tested the cytotoxic effects of 9-hydroxypheophorbide-a (9-HpbD-a) in vitro. The cultured SNU-I041 cells were treated with serial concentrations of 9-HpbD-a followed by various energy doses (0, 0.1, 0.5, 3.2 J/$cm^{2}$) and by various interval times (0, 3, 6, 9, 12 hr) until laser irradiation, then MTT assay was applied to measure the relative inhibitory effects of photodynamic therapy (PDT). Optimal laser irradiation time was 30 minutes and the cytotoxic effects according to incubation time after 9-HpbD-a treatment increased until 6 hours, after which it then showed no increase. To observe the cell death mechanism after PDT, SUN-I041 cells were stained by Hoechst 33342 and propidium iodide after PDT, and observed under transmission electron microscopy (TEM). The principal mechanism of PDT at a low dose of 9-HpbD-a was apoptosis, and at a high dose of 9-HpbD-a it was necrosis. PDT effects were also observed in a xenografted nude mouse model. Group I (no 9-HpbD-a, no laser irradiation) and Group II (9-HpbD-a injection only) showed no response (4/4, 100%), and Group III (laser irradiation only) showed recurrence (1/4,25%) or no response (3/4, 75 %). Group IV (9-HpbD-a + laser irradiation) showed complete response (10/16, 62.5%), recurrence (4/16, 25%) or no response (2/16, 12.5%). Group IV showed a significant remission rate compared to other groups (p<0.05). These results suggest that 9-HpbD-a is a promising photosensitizer for the future and that further studies on biodistribution, toxicity and mechanism of action would be needed to use 9-HpbD-a as a photosensitizer in the clinical setting.

• Journal of Life Science
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• v.30 no.2
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• pp.156-161
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• 2020

Since industrialization, the production and utilization of various chemicals has contributed to improving the quality of our lives, but the subsequent discharge of massive waste is inevitable, and environmental pollution is becoming more serious every day. Exposure to chemicals as a result of environmental pollution is having a negative effect on human health and the ecosystem, and cleaning up the polluted environment that can affect our lives is a very important issue. Toxic aromatic compounds have been detected frequently in soil, groundwater, and wastewater because of the extensive use of oil products, and phenol, which is used to produce synthetic resins, textiles, and dyes, is one of the major pollutants, along with insecticides and preservatives. Phenol can cause dyspnea, headache, vomiting, mutation, and carcinogenesis. Phenol-degrading bacterium DWB-1-8 was isolated from the activated sludge of textile wastewater; this strain was identified as Comamonas testosteroni by 16S rRNA gene sequencing. The optimal culture conditions for the cell growth and degradation of phenol were 0.7% K₂HPO₄, 0.6% NaH₂PO₄, 0.1% NH₄NO₃, 0.015% MgSO₄·7H₂O, 0.001% FeSO₄·7H₂O, an initial pH of 7, and a temperature of 30℃. The strain was also able to grow by using other toxic compounds, such as benzene, toluene, or xylene (BTX), as the sole source of carbon.

• Journal of Life Science
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• v.29 no.12
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• pp.1378-1385
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• 2019

The nutritional composition and optimal eating stage of the super mealworm, Zophobas atratus (Coleoptera : Tenebrionidae), were investigated to explore its use as a food ingredient. It was determined that 10^th instar larvae were most suitable for eating in terms of nutritional value as well as economic aspects. To improve the quality of powder production, the nutritional value of 10^th instar larvae before and after degreasing was analyzed. After drying the larvae powder, crude protein was the most abundant nutrient both before (52.3%) and after (60.6%) degreasing while crude fat measured 36.3% and 21.7% before and after degreasing, respectively. In terms of essential amino acids, leucine levels were highest and 1.3 times greater after degreasing (4.5%) than before (3.5%). Oleic acid, the highest unsaturated fatty acid in larvae, was 31.7% after degreasing which was 1.1 times higher than before (33.2%). Among various major minerals, potassium was most abundant and 1.4 times higher after degreasing (1267.0 mg/100 g) than before (879.3 mg/100 g). Harmful substances were 1.3 to 2.0 times lower in the degreased larvae, although mercury or pathogenic bacteria were not detected in either group. We therefore conclude that degreased Z. atratus larvae are more suitable for eating than before degreasing.

• Radiation Oncology Journal
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• v.13 no.4
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• pp.391-396
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• 1995

Purpose : The Conformal Radiation Therapy has bee widely used under favour of development of computer technologies. The delivery of a large number of static radiation fields are being necessary for the conformal irradiation. In this paper we investigate dosimetric characteristics on penumbra regions of a multileaf collimator(MLC), and compare to those of lead alloy block for the optimal use of the system in 3-D conformal radiotherapy. Materials and Methods : The measurement of penumbra by MLC or lead alloy block was performed with 6 or 10 MV X-rays. The film was positioned at a dmax depth and 10 cm depth, and its optical density was determined using a scanning videodensitometer. The effective penumbra, the distance from $80{\%}$ to $20{\%}$ isodose lines and $90{\%}$ to $10{\%}$ were analyzed as a function of the angle between the direction of leaf motion and the edge defined by leaves. Results : Increasing MLC angle ($0-75^{\circ}$) was observed with increasing the penumbra widths and the scalloping effect. There was no definite differences of penumbra width from $80{\%}$ to $20{\%}$ isodose lines, while being the small increase of penumbra width from $90{\%}$ to $10{\%}$ isodose line varing the depth and energy. The effective penumbra width of lead alloy block are agree resonably with those of MLC within 4.8mm. Conclusion : The comparative qualitative study of the penumbra between MLC and lead alloy block demonstrate the clinical acceptability and suitability of the multileaf collimator for 3-D conformal radiotherapy.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.346-355
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• 1997

To evaluate the utility of I-131, T1-201 scintigraphy, and serum thyroglobulin(Tg) in the follow-up of differentiated thyroid cancer, we compared retrospectively the data from 33 patients who underwent total or subtotal thyroidectomy. I-131 scintigraphy was performed after optimal endogenous TSH stimulation ($TSH>50{\mu}U/ml$). Total 41 cases of I-131 and T1-201 scintigraphy pairs were examined. Concomitant serum thyroglobulin levels were measured for 41 pairs of scan. Tg-off levels(that measured after discontinuation of the thyroid hormone) higher than 40ng/m1 were considered positive, and Tg-on levels(that measured during the thyroid hormone replacement) higher than 5ng/ml were considered positive. The concordance rates between I-131 therapeutic scintigraphy and T1-201 scintigraphy was 48% in the 38 case of total scan pairs(59% in the 17 cases of postoperative preablation group, and 38% in the 21 cases of postoperative postablation group). Of 17 studies before the I-131 ablation therapy(preablation group), 7 showed positive I-131 therapeutic scintigraphy despite of negative T1-201 scintigraphy. Among patients with negative I-131 therapeutic scintigraphy, no patients had abnormal T1-201 uptake. However, of 21 studies which were done after radioiodine therapy(postablation group) 6 had abnormal uptake on T1-201 scintigraphy which were not seen on I-131 therapeutic scintigraphy, and Tg-off levels also elevated in this 4 of 6 cases. As a result, I-131 therapeutic scintigraphy showed highest positive rate at postoperative preablation follow-up study in differentiated thyroid cancer patients. T1-201 scintigraphy may be useful in postablation studies, and the use of the combined modalities(T1-201 and Tg levels) provides a higher diagnostic yield.

• Journal of Korea Water Resources Association
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• v.48 no.12
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• pp.1065-1075
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• 2015

In the estuary where the structure such as river-mouth weir has been installed, the flow is developed very complicatedly due to river water from upstream, tide of the sea and floodgate operation. Especially, if basin outlets more than one exists in one estuary, the boundary conditions will be significantly more complex form. Saemangeum(SMG) project area in Korea is the most typical example. There are Mankyung river and Dongjin river in upstream. The water of them inflows into SMG project area. In the downstream, river flow was drained from inland to sea over the SMG sea dike through the sluice. The connecting channel was located between Mankyung and Dongjin basins. It functions not only as transportation by ship in ordinary period but also as flood sharing by sending flood flow to each other in flood period. Therefore, in order to secure the safety against flood, it is very important to understand the flood sharing capacity for connecting channel. In this study, the flood control effect was analyzed using numerical simulation. Delft3D was used to numerical simulation and simulated period was set up with neap tide, in which the maximum flood stage occurred due to poor drainage. Actually, three connecting channels were designed in land use plan of the SMG Master Plan, but they were simplified to a single channel for conciseness of analysis in this study. According to the results of numerical analysis, the water level difference between two basins was increased and the maximum flood stage at dike sluice was also upraised depending on decrease of conveyance. And the velocity induced by same water level difference was decreased when the conveyance became smaller. In certain conveyance above, there was almost no flood control effect. Therefore, if the results of this study are considered for design of connecting channel, it will be expected to draw the optimal conveyance for minimizing dredging construction cost while maximizing the flood control effect.

• Journal of Mushroom
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• v.17 no.4
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• pp.211-217
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• 2019

Currently, cultivation of mushrooms using the Information and Communication Technology (ICT)-based smart farming technique is increasing rapidly. The main environmental factors for growth of mushrooms are temperature, humidity, carbon dioxide (CO₂), and light. Among all the mentioned factors, currently, only temperature has been maintained under automatic control. However, humidity and ventilation are controlled using a timer, based on technical experience.Therefore, in this study, a Pleurotus eryngii first-generation smart farm model was set up that can automatically control temperature, humidity, and ventilation. After installing the environmental control system and the monitoring device, the environmental condition of the mushroom cultivation room and the growth of the fruiting bodies were studied. The data thus obtained was compared to that obtained using the conventional cultivation method.In farm A, the temperature during the primordia formation stage was about 17℃, and was maintained at approximately 16℃ during the fruiting stage. The humidity was initially maintained at 95%, and the farm was not humidified after the primordia formation stage. There was no sensor for CO₂ management, and the system was ventilated as required by observing the shape of the pileus and the stipe. It was observed that, the concentration of CO₂ was between 700 and 2,500 ppm during the growth period. The average weight of the mushrooms produced in farm A was 125 g, and the quality was between that of the premium and the first grade.In farm B. The CO₂ sensor was in use for measurement purposes only; the system was ventilated as required by observing the shape of the pileus and the stipe. During the growth period, the CO₂ concentration was observed to be between 640 and 4,500 ppm. The average weight of the mushrooms produced in farm B was 102 g.These results indicate that the quality of the king oyster mushroom is determined by the environmental conditions, especially by the concentration of CO₂. Thus, the data obtained in this study can be used as an optimal smart farm model, where, by improving the environmental control method of farm A, better quality mushrooms were obtained.