• The Journal of Korean Society for Radiation Therapy
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• v.31 no.2
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• pp.51-63
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• 2019

Purpose: Radiation therapy for breast cancer should consider the change in breast shape due to breathing and swelling. In this study, we evaluate the benefit of using virtual bolus for IMRT of left breast cancer. Materials and methods: 10 patients with early breast cancer who received radiation therapy after breastconserving surgery compared the VMAT and IMRT plans using the virtual bolus method and without using it. The first analysis compared the V95%, HI, CI of treatment volume, Dmean, V5, V20, V30 of ipsilateral lung, and Dmean of heart in VMAT plan made using the virtual bolus method(VMAT_VB) to the plan without using it(VMAT_NoVB) in case there is no change in the breast. In IMRT, the same method was used. The second analysis compared TCP and NTCP based on each treatment plan in case there is 1cm expansion of treatment volume. Result: If there is no change in breast, V95% in VB Plan(VMAT_VB, IMRT_VB) and NoVB Plan(VMAT_NoVB, IMRT_NoVB) is all over 99% on each treatment plan. V95% in VMAT_NoVB and VMAT_VB is 99.80±0.17% and 99.75±0.12%, V95% in IMRT_NoVB and IMRT_VB is 99.67±0.26% and 99.51±0.15%. Difference of HI, CI is within 3%. OAR dose in VB plan is a little high than NoVB plan, and did not exceed guidelines. If there is 1cm change in breast, VMAT_NoVB and IMRT_NoVB are less effective for treatment. But VMAT_VB and IMRT_VB continue similar treatment effect compared in case no variation of breast. Conclusion: This study confirms the benefit of using a virtual bolus during VMAT and IMRT to compensate potential breast shape modification.

• Korean Journal of Microbiology
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• v.17 no.3
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• pp.97-130
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• 1979

Many industrial processes those employ bacteria are subjected to phage infestations. In L-glutamic acid fermentions using acetic acid, the phage infestations of the organisms have been recently recognized. In efforts to elucidate the sources of phage contamination involved in the abnormal fermentation, a series of study was conducted to isolate the phages both from the contents of abnormally fermented tanks and the soil or sewage samples from the surroundings of a fermentation factory, to define major charateristics of the phage isolates, and finally to determine the correlation between the phage isolates and temperate phages originating from the miscellaneous bacterial species isolated from the soil or sewage samples. The results are summarized as follows; 1) All phages were isolated from the irregular fermentation tanks and soil or sewage samples, and they were designated as phage PR-1, PR-2, PR-3, PR-4, PR-5, PR-6, and PR-7, in the order of isolation. These PR-series phages were proved to be highly specific for the variant strains of Br. lactofermentum only, namely, phage PR-1 and PR-2 for Br. lactofermentum No. 468-5 and phage PR-3~PR-7 for Br. lactofemrentum No. 2256. By cross-neutralization test, the 7 phagescould be subdivided into 3 groups, i. e., phage PR-I and PR-2 the first, phage PR-3, PR-4, PR-5, PR-6 the second, and the phage PR-7 the third. 2) The 7 phages were virulent under the experimental conditions. They produced plaques with clear and relatively sharp margins without distinct halo. The mean sizes of plaques were 1.5mm in diameter for phage PR-1 and PR-2, and 1. Omm for phages PR-3~PR-7. Double layer technique modified by Hongo and described by Adams, was applied to assay of the PR-series phages. The factors influencing the plaques were as follows;young age cells of host bacteria cultured for 3-6 hours represented the largest number and size, optimum was pH 7.0, incubation temperature was $30^{\circ}C$, and agar concentration and amount of overlayer medium were 0.6% and 0.2ml, respectively. 3) PR-series phages were stable in 0.05M tris buffer and 0.1M ammonium acetate buffer solution. The addition of $5{\times}10^{-3}M$ magnesium ion effectively increased the stability. Thermostability experiments indicated that PR-series phages were stable at the teinperture between $50^{\circ}{\sim}55^{\circ}C$ in nutrient medium, $45^{\circ}{\sim}50^{\circ}C$ in buffer solution. However, the phages mere completely inactivated at 603C and 65$^{\circ}$C within 10 minutes. The phages were stable at the range of pH6~9 in nutrient medium and of pH 8-9 in buffer solution, respectively. Exposure of the phages to UV for 25, 60 and 100 seconds resulted in the complete loss of infectivily, respectively. 4) Electron microscopy showed that PR-series phage particles exhibited rather similar morphology, differing in the size All of PR-series phages had a multilateral head and had a simple long tiil about three to five times long as compared with head. By the size, phage PR-1 and PR-2, PR-3, PR-4, PR-5, and PR-6 and PR-7 were classified into same groups, respectively. The head and tail size of phage PR-1, PR-5, PR-5(T) and PR-7 were 85nm, 74nm and 235nm and 350mm, and 72nm and 210nm, respectively. 5) Nucleic acids of PR-series phages were double stranded DNA. The G+C contents of phage PR-1, PR-5 and PR-7 were 56.1, 52.9 and 53.7, respectively. The values of G+C contents derived from the $T_m$ were in agreement with the chemically determined values. 6) PR-series phages effectively adsorbed on their host bacteria at the rate of more than 90% during 5 min. K value for phage PR-1, PR-5 and PR-7 were calculated to be $6{\times}10^9 ml$ per minute, respectiveky. The pH of the medium did effect adsorption rate, but both temperature and age of host cells did not. Generally, optimum adsorption condition of phages seemed to be almost same as optimum growth conditions of host bacteria. 7) In one-step growth experiments, the latent periods at $30^{\circ}C$ for PR-1, and PR-7 were about 70, 50 and 55 min, respectively. The corresponding average burst size was 200, 70 and 90, respectively. Lpsis period according to the multiplicity of infection and a phage series. In case of m. o. i. 100, strain No. 2256 (PR-5) and No. 468-5(PR-1) failed to grow and turbidity decreased after 50 and 70min, respectively. 8) In the lysate of a plaque purified phage PR-5 infected bacteria, there observed 2 types ofphage particles, i. e., phage PR-5 and PR-5 (T) of similar morphology but differing at the length of phage tail, and phage tail like particles. The phage taillike particles could be divided into 4 types by the length. Induction experiments of Br. lactofermentum with UV irradiation, mitomycin C or bacitracin treatment produced neither phage PR-5 (T) or phage tail-like particles. 9) No lysis occured when the growth of 7 strains of miscellaneous bacteria, isolated from soil and sewage samples, were inoculated with either phage PR-5 (T) or phage tail-like particles the inoculation of phage PR-5 pellet resulted in the growth inhibition of the orgainsms in the spot test. The lysates obtained from 3 miscellaneous soil derived bacteria following mitomycin C treatment the growth of Br. lactofermentum, but did not lyze the bacterium.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.397-406
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• 2015

ZnO, II-VI group inorganic compound semi-conductor, has been receiving much attention due to its wide applications in various fields. Since the ZnO has 3.37 eV of a wide band gap and 60 meV of big excitation binding energy, it is well-known material for various uses such the optical property, a semi-conductor, magnetism, antibiosis, photocatalyst, etc. When applied in the field of photocatalyst, many research studies have been actively conducted regarding magnetic materials and the core-shell structure to take on the need of recycling used materials. In this paper, magnetic core-shell ZnFe₂O₄@SiO₂ nanoparticles (NPs) have been successfully synthesized through three steps. In order to analyze the structural characteristics of the synthesized substances, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) were used. The spinel structure of ZnFe₂O₄ and the wurtzite structure of ZnO were confirmed by XRD, and ZnO production rate was confirmed through the analysis of different concentrations of the precursors. The surface change of the synthesized materials was confirmed by SEM. The formation of SiO₂ layer and the synthesis of ZnFe₂O₄@ZnO@SiO₂ NPs were finally verified through the bond of Fe-O, Zn-O and Si-O-Si by FT-IR. The magnetic property of the synthesized materials was analyzed through the vibrating sample magnetometer (VSM). The increase and decrease in the magnetism were respectively confirmed by the results of the formed ZnO and SiO₂ layer. The photocatalysis effect of the synthesized ZnFe₂O₄ @ZnO@SiO₂ NPs was experimented in a black box (dark room) using methylene blue (MB) under UV irradiation.

• Tuberculosis and Respiratory Diseases
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• v.67 no.1
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• pp.14-20
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• 2009

Background: The pathophysiologic mechanisms of radiation-induced lung injury should be elucidated to enhance the therapeutic efficacy of radiotherapy and to manage patients exposed to serious radiation by accident. It has been suggested that pro-inflammatory cytokines play an important role in radiation-induced effect on the lung. This study was aimed to investigate changes in pro-inflammatory cytokines such as TNF-$\alpha$, MIP-2, IL-1$\beta$ and HMGB1, a newly recognized inflammatory mediator. Methods: The chests of BALB/c mice were selectively irradiated with single fraction of 20 Gy and then sacrificed at indicated times. Pathologic changes in the lung were examined after H&E staining. The expression level of pro-inflammatory cytokines was evaluated by ELISA kits in lung homogenate and in serum. Results: Radiation induced inflammatory changes and mild fibrosis in lung. Biphasic increase of TNF-$\alpha$ and IL-1$\beta$ was found in lung homogenate at 4 hours and at 3 weeks after radiation. The elevation in the second phase tended to be more intense. However, there was no similar change in serum. MIP-2 level was slightly increased in lung homogenate at 4 hours, but not at 3 weeks. HMGB1 was increased at 3 weeks in serum while there was no significant change in lung homogenate. Conclusion: Radiation induced a biphasic increase in TNF-$\alpha$ and IL-1$\beta$. The effective control of second phase cytokine elevation should contribute to preventing severe lung fibrosis caused by radiation.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.114-122
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• 1986

At present, the treatments of the radiation-induced diseases are only performing by the palliative treatment technique. Moreover, radiation protective agents are a little toxic for human being and this seriously limits their applicability with various complications in clinical uses. Accordingly, as a part of the aim of gain of the basic data for protective roles of some radioprotectors, the present investigation was carried out to evaluate the comparative radioprotective effects by the administration of DDC, MEA, WR-2721. Results are shown for statistically significant analysis and correlation with each group as follows; 1. The proper doses of the radioprotectors were DDC; 1,550 mg/kg, MEA; 450 mg/kg, WR-2721; 780 mg/kg of the mouse body weight. 2. DMF(Dose modification factor) of LD 50/10 and LD 50/30 for whole body irradiation was DDC; 1.2, MEA; 1.4, WR-2721; 1.9 and DDC; 1.7, MEA; 1.8, WR-2721; 2.5 respectively. 3. DMF for radiation reaction of jejunal crypt was DDC: 1.07, MEA: 1.21 and WR-2721: 1.76 and that of jejunal crypt cell was DDC: 1.04, MEA: 1.08 and WR-2721: 1.38 respectively. 4. Conclusively, WR-2721 was the most effective drung among the three radioprotectors and this result must be a supportive data for further study for clinical application.

• Progress in Medical Physics
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• v.24 no.2
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• pp.92-98
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• 2013

The experimental verification of treatment planning on the treatment spot is the ultimate method to assure quality of radiotherapy, so in-vivo skin dose measurement is the essential procedure to confirm treatment dose. In this study, glass rod dosimeter (GRD), which is a kind of photo-luminescent based dosimeters, was studied to produce a guideline to use GRDs in vivo dosimetry for quality assurance of radiotherapy. The pre-processing procedure is essential to use GRDs. This is a heating operation for stabilization. Two kinds of pre-processing methods are recommended by manufacturer: a heating method (70 degree, 30 minutes) and a waiting method (room temperature, 24 hours). We equally irradiated 1.0 Gy to 20 GRD elements, and then different preprocessing were performed to 10 GRDs each. In heating method, reading deviation of GRDs at same time were relatively high, but the deviation was very low as time went on. In waiting method, the deviation among GRDs was low, but the deviation was relatively high as time went on. The meaningful difference was found between mean reading values of two pre-processing methods. Both methods present mean dose deviation under 5%, but the relatively high effect by reading time was observed in waiting method. Finally, GRD is best to perform in-vivo dosimetry in the viewpoint of accuracy and efficiency, and the understanding of how pre-processing affect the accuracy is asked to perform most accurate in-vivo dosimetry. The further study is asked to acquire more stable accuracy in spite of different irradiation conditions for GRD usage.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.188-198
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• 2017

Asparagus (Asparagus officinalis L.) spears were treated with white (color temperature 4,500 k), blue (peak 450 nm), and red (peak 660 nm) light-emitting diodes (LEDs) at a photosynthetic photon flux density (PPFD) of $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for 12 h, and UV-B (280 nm) at 0.5 kJ or 1.0 kJ to determine the effect on agronomic characteristics, antioxidant phytochemicals, and antioxidant activity. The fresh weight, length, and width of spears were not affected by light quality treatments. The free sugars and chlorophyll contents were increased by 9 and 41%, respectively in the UV-0.5 kJ treatments. Among the antioxidant phytochemicals (vitamin C, total phenol, rutin, and total flavonoid), vitamin C was most greatly affected by the light treatments. Vitamin C content was significantly increased in asparagus spears subjected to the white (114%), red (137%), and UV-0.5 kJ(127%) treatments compared to the control. By contrast, rutin, total phenol, and total flavonoid content were increased only in samples subjected to the red and UV-0.5 kJ treatment. Furthermore, antioxidant activity, as measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, increased in white, red, and UV-0.5 kJ treatments by about 43, 41, and 43%, respectively, compared to the control. These results suggest that postharvest treatment of asparagus spears with red light at $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for 12 h or with UV-B (280 nm) at 0.5 kJ could enhance the functional quality of the asparagus spears by increasing the content of phytochemicals like vitamin C, rutin, total phenolics, and total flavonoids.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.335-341
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• 2011

This paper searched the affect of Water dropwort and Tumeric on radiation exposure. By experimenting 50 male mouse, ICR type 5 weeks old male 25~30g, 5 mouse was divided in to each group respectively. A : 3 Gy control group, B : 5 Gy control group, C : 3 Gy, FW, D : 5 Gy FW, E : 3 Gy LW, F : 5 Gy LW, G : 3 Gy FT, H : 5 Gy FT, I : 3 Gy LT, J : 5 Gy LT FW : Ate Water dropwort before the radiation exposure. FT : Ate Tumeric before the radiation exposure. LW : Ate Water dropwort after the radiation exposure. LT : Ate Tumeric after the radiation exposure. During the 7 day radiation, Control group (A, B) received physiological saline (500mg/kg/day) in oral administration, LW and LT group (E, F, I, J) respectively received Water dropwort or tumeric (500mg/kg/day) in oral administration after the radiation, FW and FT group (C, D, G, H) respectively received Water dropwort or tumeric (500mg/kg/day) in oral administration before the radiation. As a result, an average leukocyte rate on 5 mouse was 200K/${\mu}L$ on group A. 6.46K/${\mu}L$ on group C which was in normal rate range (1.8-10.7 K/${\mu}L$). An average leukocyte rate was 23.33K/${\mu}L$ on group G. which was not normal rate, but compare to 200K/${\mu}L$, it was closer to normal rate. An average lymphocyte rate was 118.87K/${\mu}L$ on Group A. 1.51K/${\mu}L$ on Group G. which was in normal lymphocyte rate range (0.9-9.3K/${\mu}L$). An average thrombocyte rate was 4000K/${\mu}L$ on Group A. 1107 K/${\mu}L$ on Group C. 2759.6 K/${\mu}L$ on Group G. which was in normal thrombocyte rate range (592-2972 K/${\mu}L$). From this result, it was found that when exposed to radiation, Water dropwort and Tumeric have defensive effect in a preventive level. Also from an animal experiment, it was found that blood corpuscle rate returns to a normal rate. Based on this experiment, diverse research on this field should be conducted.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.241-246
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• 2013

The purpose of this study was to investigate the synergistic effects of erythrosine sensitized with a conventional halogen curing unit and sub-minimal bactericidal concentration(sub-MBC) of chorhexidine on bacterial viability of Streptococcus mutans in planktonic state. Sub-minimal bactericidal concentration of chlorhexidine was added into wells containing bacteria and erythrosine. The range of concentrations tested for chorhexidine was from 0.0000001% to 0.001%. The irradiation of the bacterial suspensions was performed for 15 sec with a conventional halogen curing unit light. In another set of experiment, the effects of 0.001% chlorhexidine were observed by adding chlorhexidine into wells containing the sub-minimal bactericidal concentration of erythrosine. At the concetration of 0.001% chlorhexidine, there were no antibacterial effects in the absence of erythrosine PDT(p < 0.05). At the concentraton of $1{\mu}M$ erythrosine, there was no photodynamic therapy effect in the absence of chlorhexidine(p < 0.05). But in the presence of sub-minimal bactericidal concentration of erythrosine with light exposure, the addition of 0.001% chlorhexidine increased the bactericidal rate(p < 0.05). A combination of erythrosine PDT with sub-MBC chlorhexidine resulted in a significant reduction in bacterial counts when compared to the case with the absence of chlorhexidine.

• The Korean Journal of Nuclear Medicine
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• v.35 no.2
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• pp.83-88
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• 2001

Purpose: The purpose of this study was to ascertain whether radiation adaptive response could be induced by high dose I-131 therapy in patients with differentiated thyroid cancer. Materials and Methods: Lymphocytes from 21 patients (7 males, 14 females, mean age $55{\pm}12$ years) were collected before and after administration of 5,550 MBq (150 mCi) I-131. They were exposed to a challenge dose of 1 Gy gamma rays using a Cs-137 cell irradiator. The number of ring-form (R) and dicentric (D) chromosomes was counted under the light microscope, and used to calculate the frequency of chromosomal aberration. Ydr, which was defined as the sum of R and D divided by the total number of counted lymphocytes. Results: Ydr in patients before I-131 therapy ($0.09{\pm}0.01$) was not different from that of controls ($0.08{\pm}0.01$). Ydr was significantly increased to $0.13{\pm}0.02$ (p<0.0001) after I-131 therapy. Increase of Ydr after the challenge irradiation of 1 Gy was significantly lower in patients after I-131 therapy than before I-131 therapy ($0.17{\pm}0.03\;vs\;0.21{\pm}0.02$, p<0.0001). Cycloheximide (CHM), an inhibitor of protein synthesis, abolished this effect. Ydr after CHM ($0.20{\pm}0.01$) was significantly higher than Ydr after I-131 therapy ($0.17{\pm}0.03$, p<0.0001), but was not different from Ydr before I-131 therapy ($0.21{\pm}0.02$).Conclusion: High dose I-131 therapy induces an adaptive response in peripheral lymphocytes of patients with well-differentiated thyroid cancer, which is associated with protein synthesis.