• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.347-353
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• 2010

Source terms of metal waste comprising a spent fuel assembly are relatively important when the spent fuel is pyroprocessed, because cesium, strontium, and transuranics are not a concern any more in the aspect of source term of permanent disposal. In this study, characteristics of radiation source terms for each structural component in spent fuel assembly was analyzed by using ORIGEN-S with a assumption that 10 metric tons of uranium is pyroprocessed. At first, mass and volume for each structural component of the fuel assembly were calculated in detail. Activation cross section library was generated by using KENO-VI/ORIGEN-S module for top-end piece and bottom-end piece, because those are located at outer core with different neutron spectrum compared to that of inner core. As a result, values of radioactivity, decay heat, and hazard index were reveled to be $1.40{\times}10^{15}$ Bequerels, 236 Watts, $4.34{\times}10^9m^3$-water, respectively, at 10 years after discharge. Those values correspond to 0.7 %, 1.1 %, 0.1 %, respectively, compared to that of spent fuel. Inconel 718 grid plate was shown to be the most important component in the all aspects of radioactivity, decay heat, and hazard index although the mass occupies only 1 % of the total. It was also shown that if the Inconel 718 grid plate is managed separately, the radioactivity and hazard index of metal waste could be decreased to 20~45 % and 30~45 %, respectively. As a whole, decay heat of metal waste was shown to be negligible in the aspect of disposal system design, while the radioactivity and hazard index are important.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.150-156
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• 2008

The influences of night break by costly artificial light sources were investigated on the photo-morphogenesis and growth of leafy perilla (Perilla ocymoides L.). The irradiation of red, blue, and three-colored light for night break significantly increased the stem length and stem diameter compared to dark. Three-colored light gave the highest fresh and dry weight of stem, followed by red and blue light. Floral induction was suppressed up to 100 days after the night break, by red and three-colored light, but the plants grown under the dark or treated with blue light showed 85% and 31% flowering rate, respectively. The time needed for floral induction after night break was 60 days in dark and 80 days in blue light. The number of leaf, leaf area, and fresh weight per plant were the highest in red and three-colored light night break, followed by blue light and dark. The photosynthetic rate observed 80 days after night break was the highest in red light, followed by blue and three-colored light. A low light compensation point of $20\;{\mu}mol\;m^{-2}{\cdot}s^{-1}$ was observed in three-colored light, while red and blue light tended to show higher measurements.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.95-106
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• 1996

The infestation rates and abundances of human infecting metacercariae (Clonorchis sinensis, Metcgonimus spry. , Centrocestus crmatus, Echinostoma hortense, Echinochusnus japonicw, Clinostomum complanctum) in freshwater fish were investigated at the three river areas - Taewhagang (river), Hyongsangang (river), Nakdonggang (river) - in Kyongsang-do and at four streams - Yonpungchon, Munsanchon, Kyonganchon, and Konjiamchon- in Kyonggi-do, Korea in 1994-1995. The fish caught at Taewhagang were heavily infested with metacercariae of Clonorchis sinensis and Centrocestw armctus. At Hyongsangang, Zncco platypus and Z. temmincki were moderately infested with metacercariae of C. crmctus. Chomanpo, at the basin of Nakdonggang, was still endemic for C. sinensis. In the fish caught at four streams of Kyonggi-do, metacercariae of C. sinensis exhibited the highest infestation rate and intensity out of 6 species of metacercariae. The infestation intensity of C. sinensis metacercariae in fish flesh was markedly different according to each division of flesh. The cause of this difference was conjectured as a result of larval behavior. The metacercariae of C. omnt5 were found in almost all parts, except scales and fins, of fish. The infestation rates and intensities of C. sinensis and C. armntus metacercariae in Taewhagang greatly increased as compared with those of previous reports . RhinoBobius bmnneus and Aconthorhone5 macropterus are newly recorded intermediate hosts of Echinostonn hortense. The reason of large differences from previous data was discussed and the standard method of metacercaria examination was proposed.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.153-158
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• 2013

This research was carried out to investigate silicon (Si) uptake levels by six potted plant species from a nutrient solution supplemented with $K_2SiO_3$. Uniform rooted plants of Dendranthema grandiflorum Ramat., Spathiphyllum patinii N.E. BR., Kalanchoe blossfeldiana, Hedera helix L., Dianthus caryophyllus L., and Euphorbia pulcherrima Willd. were grown in 350 mL boxes, one plant per box, containing a nutrient solution supplemented with either 0, 2.7, or 5.4 mM Si as $K_2SiO_3$. The nutrient solution in each container was adjusted to EC $1.5mS{\cdot}cm^{-1}$ and pH 5.6. The solution in each container was aerated by an 1 m-long polyethylene tube, all connected to a vacuum pump. After 15 days of cultivation in a glasshouse Si contents in the roots and shoots were measured using the colorimetric molybdate method and amount of remaining Si in the nutrient solution was measured using the ICP-AES to calculate the amount of absorption. A simple regression analysis was performed to observe the changes in Si contents in the roots and shoots as affected by concentration of Si supplied to the solution. Among the six species tested, carnation had the greatest and poinsettia the lowest tissue levels of Si concentration in the root, whereas carnation had the greatest and kalanchoe the lowest tissue levels of Si concentration in the shoot. Based on the Si content in the whole plant, Si uptake levels by poinsettia, kalanchoe, and chrysanthemum were low, whereas those by spathiphyllum were intermediate, and those of English ivy and carnation were high. These results indicated that the uptake level of Si by the plant vary depending on plant species.

• Applied Microscopy
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• v.38 no.1
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• pp.21-28
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• 2008

Carnivorous plants vary in their unique features of morphology, ultrastructure and biochemical properties by species. Furthermore, prey-capturing mechanism as well as structural and physiological adaptations have been used for grouping various carnivorous species. In Drosera plants, glandular trichomes, which develop in the leaf epidermis, are known to play the most important role during the prey capturing process. The present study examined such trichomes, focusing on the glandular type, in leaves of Drosera anglica using scanning and transmission electron microscopy. Three types of rudimentary glandular trichomes were found to develop within the folded leaf primordia and immature leaf during early development. The first type, stalked glandular trichomes (Type I), occurred on the margin and upper epidermis of the leaf. With maturation, the longest glandular trichomes having lengthy stalks, ca. $2.2{\sim}5.1\;mm$, developed along the margin, while shorter stalked trichomes, ca. up to $200\;{\mu}m$, were found on the inner leaf blade. The shorter ones consisted of a globose head having two layers of secretory cells, parenchyma bell cells and tracheids and a multicellular stalk. The stalks gradually decreased in length in centripetal fashion. The second type, Type II, having ca. $15{\sim}30\;{\mu}m$ short stalks, also developed along the inner blade. Both types secreted mucilage from the secretory cells which had a thin cell wall and cuticle layer. The sessile six-celled glandular trichomes were the third type, Type III, and were $25{\sim}40\;{\mu}m$ in length. They were distributed most commonly throughout the upper and lower epidermis, petiole and even on the stalk surfaces of the first two types of trichomes. The third type was also found to be involved in the active secretion. In prey capturing leaves, all trichome types secreted substances through thin cuticles in the head cell wall, which exhibited relatively loose wall components.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1179-1186
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• 2010

The antiradical property of hot water extract from dried radish (DR) or dried radish roasted with pressure (DRRP) was investigated in vitro and in LLC-PK1 cell system. The contents of total free amino acid and reducing sugar in DR were decreased by 72.86% and 3.17%, respectively, after pressurized roasting. In vitro test, $IC_{50}$ for DR and DRRP for DPPH radical scavenging activity were 646.70 and $135.45\;{\mu}g/mL$, 896.10 and $566.98\;{\mu}g/mL$ for superoxide anion radical, and 722.26 and $531.84\;{\mu}g/mL$ for hydroxy radical, respectively. The radical scavenging effects of DRRP was significantly greater than those for DR (p<0.001). These radical scavenging effects of DR and DRRP were confirmed in LLC-$PK_1$ at which oxidative stresses were induced by superoxide, nitric oxide and peroxynitrite generated in the treatment of pyrogallol, SNP, and SIN-1, respectively. Cell viability was increased in the presence of DR or DRRP, dose dependently (p<0.05), and TBARS formation was decreased. The protective effects of DRRP against oxidative damage in LLC-$PK_1$ were greater than those of DR at the same concentration tested (p<0.05). This superior antiradical activity of DRRP might be due to the products produced during the pressurized roasting in addition to the antioxidative compounds originally present in the radish. 5-hydroxyl methyl furfural (5-HMF) known as an intermediate product of the maillard reaction was detected in DRRP (0.57 mg/g), but not from DR. In conclusion, daily consumption of DRRP may prevent oxidative damage by retarding oxidative stress.

• Ocean and Polar Research
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• v.27 no.2
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• pp.125-133
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• 2005

This study described the phonology and reproductive potential of four species of Korean seagrasses, Zostera caespitosa, Z. caulescem, Z. Japonica and Z. marina. Z. caespitosa and Z. caulescens sampled from a mixed stand at the subtidal area of Yulpo Bay, Geojedo of the South Sea of Korea in November 2002 and August 2003. Z japonica and Z. marina occurred at the depth between the middle intertidal and shallow subtidal (<1m below mean sea level) of Seungbongdo (in Yellow Sea) samples collected in February and October 2003. The sexual reproductive phase of the four Zostera species was apparently different in timing of flowering, reproductive period, fruiting and seed maturing. Z. caespitosa flowered from February to early May $(10-16^{\circ}C)$, and its seed production completed in early May. The reproductive shoots of Z. caulescens began to appear in January $(9^{\circ}C)$, and its flowering followed from February to June $(10-19^{\circ}C)$. The flowers of Z. japonica were observed from July to September $(18-22^{\circ}C)$, and its seeds matured from August to September. The most commonly I marina flowered from April to August $(7-21^{\circ}C)$ and developed into seeds in July. Z. caulescens, the largest plant, had the highest number of seeds per shoot and longest spadix length. Z. marina, which was intermediate In size, recorded the highest reproductive potential. The study indicates that the reproductive phase and potential of the four species of seagrass from Korea are highly related to water temperature, and the populations of these species show a perennial lifespan with a low sexual reproductive input.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.31-39
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• 2002

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water column can accumulate in sediments at much higher levels. The purpose of this study was to make optimal treatment and disposal plan o( sediment for water quality improvement in small-scale resevoir based on an evaluation of degree of contamination. The degree of contamination were investigated for 23 samples of 9 site at different depth of sediment in small-scale J river. Results for analysis of contaminated sediments were observed that copper concentration of 4 samples were higher than the regulation of hazardous waste (3 mg/L) and that of all samples were exceeded soil pollution warning levels for agricultural areas. Lead and mercury concentration of all samples were detected below both regulations. Necessary of sediment dredge was evaluated for organic matter and nutrient through standard levels of Paldang lake and the lower Han river in Korea and Tokyo bay and Yokohama bay in Japan. The degree of contamination for organic matter and nutrient was not serious. Compared standard levels of Japan, America, and Canada for heavy metal, contaminated sediment was concluded as lowest effect level or limit of tolerance level because standard levels of America and Canada was established worst effect of benthic organisms. The optimal treatment method of sediment contained heavy metal was cement-based solidification/stabilization to prevent heavy metal leaching.

• Pediatric Infection and Vaccine
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• v.25 no.2
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• pp.82-90
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• 2018

Purpose: Survival after liver transplantation (LT) has improved over the years, but infection is still a major complication. We aimed to identify the characteristics of bacterial infections in pediatric LT recipients. Methods: This study is a retrospective review of 189 consecutive children undergoing LT between 2000 and 2015 at a single center. In this study, the incidence of infection was determined for the following periods: within 1 month, between 1-5 months, and between 6-12 months. Patients who underwent liver transplants more than once or multiple organ transplants were excluded. Results: All patients had received postoperative antibiotic for 3 days. Only the maintenance immunosuppression with oral tacrolimus and steroids were performed. As a result, 132 bacterial infections developed in 87 (46.0%) patients (0.70 events per person-year). Bacterial infections occurred most frequently within the first month (n=84, 63.6%) after LT. In the pathogens, Staphylococcus aureus (15.2%), Enterococcus species (15.2%), and Klebsiella species (13.6%) were most common. Regarding the organ infected, bloodstream was most common (n=39, 29.5%), followed by peritoneum (n=28, 21.2%), urinary tract (n=25, 18.9%), and lungs (n=20, 15.2%). We changed prophylactic antibiotics from ampicillin-sulbactam to piperacillin-tazobactam at 2011, October, there were no significant effects in the prevalence of antibiotics resistant bacterial infections. The 1-year mortality was 9.0% (n=17), in which 41.2% (n=7) was attributable to bacterial infection; septicemia (n=4), pneumonia (n=2), and peritonitis (n=1). Conclusions: The incidence and type of bacterial infectious complications after LT in pediatric patients were similar to those of previous studies. Bacterial complications affecting mortality occur within 6 months after transplantation, so proper prophylaxis and treatment in this period may improve the prognosis of LT.

• Research in Plant Disease
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• v.15 no.2
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• pp.120-126
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• 2009

In the course of study on the roles of phytotoxins in the pathogenicity of Botrytis cinerea, we isolated two novel phytotoxins. They were identified as 3-O-acetyl botcinol and 3-O-acetyl botcinolide. In this study, we investigated correlation between the two phytotoxins and the pathogenicity of B. cinerea. In liquid cultures, the two phytotoxins were not produced by three low pathogenic isolates out of 25 B. cinerea isolates. Among strong or moderate pathogenic isolates, some produced the two phytotoxins, but the others did not. On the other hand, the ethyl acetate extracts of fermentation broths of 10 out of 25 isolates showed phytotoxic activity against various plants tested in a whole plant assay. The phytotoxins were detected in all of the 10 phytotoxic ethyl acetate extracts. In planta, the two phytotoxins were detected in all of the plant tissues infected with strong pathogenic isolates. However, there was no correlation between the ability of B. cinerea isolates to produce the two phytotoxins and their pathogenicities. The two phytotoxins began to detect in tomato plant tissues infected with B. cinerea 2-16 at 3 days after inoculation, increased gradually till 4 days after inoculation, and then decreased. The above results suggest that 3-O-acetyl botcinol and 3-O-acetyl botcinolide are one of pathogenicity factors for B. cinerea, but not a primary determinant of its pathogenicity.