• Horticultural Science & Technology
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• v.34 no.1
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• pp.84-93
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• 2016

Plant factories with artificial lights require a large amount of electrical energy for lighting; therefore, enhancement of light use efficiency will decrease the cost of plant production. The objective of this study was to enhance the light use efficiency by using filters to diffuse the light from LED sources in plant factory conditions. The two treatments used diffuse glasses with haze factors of 40% and 80%, and a control without the filter. For each treatment, canopy light distribution was evaluated by a 3-D ray tracing method and canopy photosynthesis was measured with a sealed acrylic chamber. Sixteen lettuces for each treatment were cultivated hydroponically in a plant factory for 28 days after transplanting and their growth was compared. Simulation results showed that the light absorption was concentrated on the upper part of the lettuce canopy in treatments and control. The control showed particularly poor canopy light distribution with hotspots of light intensity; thus the light use efficiency decreased compared to the treatments. Total light absorption was the highest in the control; however, the amount of effective light absorption was higher in treatments than the control, and was highest in treatment using filters with a haze factor of 80%. Canopy photosynthesis and plant growth were significantly higher in all the treatments. In conclusion, application of the diffuse glass filters enhanced the canopy light distribution, photosynthesis, and growth of the plants under LED lighting, resulting in enhanced the light use efficiency in plant factory conditions.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.77-82
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• 2004

DA-125, a novel derivative of adriamycin, is known for its anti-cancer activity. In this study, the inhibitory mechanism of DA-125 on topoisomerase was investigated in the simian virus 40 (SV40) replicating CV-1 cell by studying the SV40 DNA replication intermediates and DNA-topoisomerase complexes. DNA-protein complexes that were formed in the drug-treated cells were quantitated by using a glass filter assay. SV40 DNA replication intermediates that were accumulated in the drug-treated CV-1 cell were analyzed in a high resolution gel. DA-125 did not accumulate B-dimers of SV40 DNA replication intermediates which were found in the adriamycin-treated CV-1 cells. DA-125 induced a dose-dependent formation of the DNA-protein complexes, while adriamycin did not. When adriamycin and etoposide (VP16) were added to the SV40-infected cells at the same time, adriamycin blocked the formation of the DNA-protein complexes induced by VP16 in a dose-dependent manner. However, DA-125 blocked the formation of the DNA-protein complexes induced by VP16 up to the maximum level of the DNA-protein complexes that were induced by DA-125 alone. Adriamycin and DA-125 did not inhibit the formation of the DNA-protein complexes that were caused by camptothecin, a known topoisomerase I poison. DA-125 is bifunctional in inhibiting topoisomerase II because it simultaneously has the properties of the topoisomerase II poison and the DNA intercalator. As a topoisomerase II poison, DA-125 alone induced dose-dependent formation of the DNA-protein complexes. However, as a DNA intercalator, it quantitatively inhibited the formation of the DNA-protein complexes induced by a strong topoisomerase II poison VP16. Furthermore considering that the levels of the DNA-protein complex induced by VP16 were decreased by DA-125 in terms of the topoisomerase II poison, we suggest that DA-125 has a higher affinity to the drug-binding sites of DNA than VP16 has.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.337-343
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• 2014

Purpose : The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. Materials and Methods : The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Results : Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of $64.94{\pm}0.84mGy$ and $37.64{\pm}1.20mGy$ in left ovary part and average of $64.38{\pm}1.85mGy$ and $32.96{\pm}1.11mGy$ in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Conclusion : Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.1
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• pp.65-74
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• 2011

Purpose: In this study we investigated improvement degree of reading ability of the student who was in a condition of dyslexia symptoms by wearing $ChromaGen^{TM}$ lenses. Methods: After wearing the $ChromaGen^{TM}$ lens for 3 months, the dyslexia symptoms corrective lens, 52 students who had suspected symptom of dyslexia were asked questions, and we measured the improvement degree of reading ability of the student. Results: The $ChromaGen^{TM}$ wearer read 110.26${\pm}$22.07 words in 1 minute, and naked yeses or glass wearing students read 106.42${\pm}$22.70 words. Reading ability of the student having suspected symptom of dyslexia were measured after wearing $ChromaGen^{TM}$ for 3 months. The results showed improvement reading ability of 3.70${\pm}$0.29 (p=0.01, t=2.26), 4.50%${\pm}$0.10 (p=0.01, t=2.78) for $ChromaGen^{TM}$ wearer with statistical difference. A survey on the satisfaction of reading improvement with wearing $ChromaGen^{TM}$ showed that 88.4% of questioned person answered wearing $ChromaGen^{TM}$ had improved their dyslexia symptoms. Conclusions: With statisical significance (p<0.05). this study suggests that $ChromaGen^{TM}$ lens has an effect on improving reading speed of dyslexia patient. We know from these results that the $ChromaGen^{TM}$ lens which is used to dyslexia had an effect to improvement of reading speed for dyslexia. And the results of this study is statistically different (p<0.05).

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.279-285
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• 2005

Background : Ambient particles during Asian dust events are usually less than $10{\mu}m$ in size, and known to be associated with the adverse effects on the general population. There is little evidence linking Asian dust to adverse effects on the airways. In 2002, the authors found that particulate matter during Asian dust events had an effect on the symptoms and pulmonary function of patients with bronchial asthma. An aggravating factor might be that of a viral infection, but this remains unclear. Conversely, it has been speculated that African dust may carry the virus responsible for foot and mouth disease. Asian dust events are also likely to be responsible for transporting viruses, some of which are pathogenic, and common in many environments. Therefore, in this study, air samples were screened for the presence of viruses. Methods : Air samples were collected 20 times each during Asian dust events and under non-dust conditions, for at least 6 hours per sample, using a high volume air sampler (Sibata Model HV500F), with an airflow rate of 500L/min, between April and August 2003, and between April and August 2004. The samples were then screened for the presence of targeted viruses (Influenza A, B, Hog cholera virus, and Aphthovirus) using a polymerase chain reaction method. Results : One Asian dust event occurred between April and August 2003, and 3 between April and August 2004, with a 24 hour average PM10 level of $148.0{\mu}g/m^3$. The 24 hour average PM10 level was $57{\mu}g/m^3$. There was a significant difference in the PM10 concentration between dusty and clear days. No viruses (Influenza virus, Aphthovirus, and Hog cholera virus) were identified in the air samples obtained during the dusty days. Conclusions : Although no virus was detected in this study, further studies will be needed to identify suspected viruses carried during Asian dust events, employing more appropriate virus detection conditions.

• Analytical Science and Technology
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• v.32 no.6
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• pp.243-251
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• 2019

Microplastics (MP) are found in large quantities in the oceans, posing a major threat to the ecosystem. In Korea, MPs have been reported to be detected in sea salts. In order to analyze MPs, information on their composition, size, and shape is required. FT-IR microscopy is used frequently to measure sizes larger than 20 ㎛. Recently, however, Raman microscopy, which can analyze ultrafine plastics below 20 ㎛, has been applied extensively. In this study, 10.0 g samples of commercially available salts were dissolved and filtered through a 45 ㎛ mesh filter with a size of 25.4 mm × 25.4 mm. These filtered samples were then analyzed by both FT-IR microscopy and Raman microscopy. A total of four MPs, including three polyethylene (PE) of size 70-100 ㎛ and a polypropylene (PP) of size 170 ㎛, were detected by FT-IR microscopy, while 10 MPs, including nine PE of size 10-120 ㎛ and one polystyrene (PS) of size 40 ㎛, were detected by Raman microscopy. Approximately, 1,000 MPs/kg was estimated, which was almost two times higher than the previous reported levels (~550-681 particles/kg in sea salts); this is because Raman microscopy can detect much smaller MPs than FT-IR microscopy. A total of 113 particles were found using Raman microscopy: Carbon (35, 31.5 %), minerals (28, 25 %), and glass (16, 14.4 %) were dominant, forming around 70% of the total, but MPs (10, 8.8 %) and cellulose (5, 4.5 %) were also found. Raman microscopy has great potential as an accurate method for measuring MPs, as it can measure smaller size MPs than FT-IR microscopy. It also has a reduced sample preparation time.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.286-293
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• 2016

BACKGROUND: 18% of difenoconazole+iminoctadin triacetate microemulsion (3%+15%) formulation were mixed and sprayed as closely as possible to normal practice on the ten of farms located in the Youngju of South Korea. Patches, cotton gloves, socks, masks and XAD-2 resin were used to measure the potential exposure for applicators wearing standardized whole-body outer and inner dosimeter (WBD). This study has been carried out to determine the dermal and inhalation exposure to difenoconazole during preparation of spray suspension and application with a power sprayer on a grape orchard. METHODS AND RESULTS: A personal air monitor equipped with an air pump IOM sampler and cassette and glass fiber filter were used for inhalation exposure. The field studies were carried out in a grape orchard. The temperature and relative humidity were monitored with a thermometer and a hygrometer. Wind speed was measured using a pocket weather meter. All mean field fortification recoveries were between 97.3% and 119.6% in the level of 100 LOQ (limit of quantification) while the LOQ for difenoconazole was $0.025{\mu}g/mL$ using HPLC-UVD. The arms exposure to difenoconazole for the mixer/loader (0.0794 mg) was higher than other body parts (head, hands, upper body, legs). The exposure to difenoconazole in the legs for applicator (3.78 mg) was highest in the parts of body. The dermal exposure for mixer/loader and applicator were 0.02 and 2.28 mg on a grape orchard, respectively. The inhalation exposure during application was estimated as 0.02 mg. The ratio of inhalation exposure to dermal exposure was equivalent to 0.9% of the dermal exposure. CONCLUSION: The inhalation exposure for applicator indicated $18.8{\times}10^{-3}mg$, which was level of 0.9% of the dermal exposure (2.28 mg). Operator exposure (0.004 mg/kg bw/day) to difenoconazole during treatment for grape is calculated as 2.5% of the established AOEL (0.16 mg/kg bw/day).

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.343-349
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• 2012

Exposure and risk assessments were conducted to evaluate the relative safety of mixing/loading work of indoxacarb between wettable powder (WP) and water dispersible granule (WG). Hand exposure was monitored using cotton gloves while inhalation exposure was measured using personal air monitor. Method validation for the exposure monitoring was established successfully through several experiments. Limit of determination and limit of quantitation were 0.25 and 1 ng, respectively. $R^2$ of calibration curve linearity was more than 0.9999 and reproducibility was 0.7-6. Recovery of indoxacarb from gloves, solid sorbent and glass fiber filter at three different levels was 81.5-108.8%. Trapping efficiency and breakthrough tests gave 981.5-108.8% of recovery. During mixing/loading procedure, hand exposure amount (75 percentile of 30 repetitions) for indoxacarb WP was 6 folds (459.8 mg/kg a.i) than that of WG (81.4 mg/kg a.i). This result indicates that WG has less drift than WP thanks to its granular type of formulation. Inhalation amount was $10^{-8}-10^{-7}%$ of spray mixture prepared and $10^{-4}-10^{-3}%$ of hand exposure. In inhalation case, no significant differences were observed between two formulations. Margin of safety was calculated for risk assessment using male Korean average body weight and acceptable operator exposure level as the important exposure factors. Mixing/loading procedures for both of the formulations were considered to be of least risk because calculated MOS values were more than 1.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.24-29
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• 2003

In the previous reports, the authors isolated two strains of marine bacteria, Shewanella sp. SR-14, which has Chaetonros sp. growth inhibition activity, and Vibrio alginolyticus, that did not affect growth of the alga. In the present study, fatty acid compositions of diatoms, Chaetoceros calcitrans and Skeletonema costatum, and marine bacteria, Shewanella sp. SR-14 and V. alginolyticus, were analyzed. Changes of fatty acid composition in the diatoms grown with the marine bacteria were also determined. Major fatty acids of Sbewanella sp. SR-14 were 16:1n-7 $(29.4\%)$ and 16:0 $(19.2\%)$ during incubation in peptone broth at $20^{\circ}C$ for 3 days. The compositions of V. alginolyticus detected were 16:0 $(23.7\%),$ 16:1n-7 $(27.7\%)$ and 18:1n-7 $(21.0\%).$ C. calcitrans consisted of 16:1n-7 $(33.3\%),$ 16:0 $(27.1\%)$ and 14:0 $(12.1\%).$ S. costatum mainly contained 16:1n-7 $(28.9\%),$ 16:0 $(21.6\%)$ and 20:5 $(19.8\%).$ When halves of cell numbers of C. calcitrans were moribund cells by Shewanella sp. SR-14, the C. calcitrans and S. costatum simultaneously cultured with the bacteria were harvested by filtration with GE/D glass microfibre filter. In the fatty acid composition of both diatoms, saturated fatty acid contents in both diatoms grown with Shewanella sp. SR-14 were decreased, but unsaturated fatty acid contents were increased. The differences were greater in C. calcitrans than those in S. costatum. During the growth of diatoms with V. alginolyticus, C. calcitrans showed increase of saturated fatty acid contents and decrease of unsaturated fatty acid contents; however, S. costatum did not show sharp difference in fatty acid content. In this study, Shewanella sp. SR-14, which showed growth inhibition activity against C. calcitrans, influenced on the changes of fatty acid contents in the diatom. It was suggested that increased unsaturated fatty acid was synergistically activated algal growth inhibition activity of Shewanella sp. SR-14.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.51-55
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• 2004

The most commonly used inorganic nutrient compositions such as Murashige & Skoog medium have been optimized for heterotrophic growth. Therefore, they may not be optimal for photomixotrophic and photoautotrophic growth of plantlets. In photomixotrophic micropropagation, emdium sugar level is often lowered, while light and $CO_2$ levels in vessel are raised, and chlorophyllous explants are used to facilitate photosynthetic carbon acquisition. In a factorial experiment effect of addition (+) and omission(_) of organic materials (OM, 0.5 g ${\cdot}$ $m^{-3}$ each of thiamine, nicotinic acid and pyridoxine and 100 ${\cdot}$ $m^{-3}$ myo-inositiol) combined with three sucrose levels (0, 15, and 30 kg ${\cdot}$ $m^{-3}$) was tested on the growth of potato plantlets. Each of nodal cuttings with a leaf was cultured on 0.1${\times}$$10^{-4}m^{-3}$) MS agar ( 8 kg ${\cdot}$ $m^{-3}$) medium (pH 5.80 before autoclave) in glass test tubes (100 mm${\times}$25mm) capped with a sheet of transparent film with a 6 mm diameter gas permeable filter (5.1 air exchanges ${\cdot}$$h^{-1}$). Cultures were maintained in a room for 27 days at $23^{\circ}C$, 50% RH, 350-450${\mu}mol\;{\codt}\;mol^{-1}CO_2$, 16 h ${\cdot}$ $d^{-1}$ photoperiod at 13${\mu}mol\;{\codt}\;m\;{\codt}\;s^{-1}$ PPFD provided by white cool fluorescent lamps. Growth of potato plantlet in the +OM and -OM treatments were similar, while medium pH was 0.2 scale lower in the latter. Dry weight, % dry matter, and stem diameter enhanced, while shoot to root dry weight ratio, leaf area, chlorophyll concentration per gram dry weight, and medium pH decreased with increasing initial sucrose level. Interaction between OM and sucrose levels was observed in shoot length and medium pH. Results indicate that OM can be omitted from the medium without detrimental effect while addition of sucrose was beneficial for the photomixotrophic growth of potato plantlets under raised light and $CO_2$.