• Radiation Oncology Journal
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• v.18 no.4
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• pp.226-232
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• 2000

Purpose :This study was performed to find out the prognostic factors affecting local control in early glottic cancer treated with radiation therapy alone. Materials and Methods :We analysed 37 patients of histologically confirmed early glottic cancer treated at Chonnam National University Hospital between July Im and December 1995, retrospectively. Age of patients ranged from 30 to 73 years (median; 59 years). Thirty-five (95$\%$) patients were male. Histological type was all squamous cell carcinoma. According to the staging system of 1997 American Joint Committee on Cancer, 37 patients were restaged as follows: Tla; U (73$\%$), Tlb; 3 (8$\%$), 72: 7 (19$\%$). Radiation therapy was done using 6 MV X-ray of linear accelerator The range of total radiation dose delivered to the glottic lesion was between 5,040 cGy and 7,020 cGy (median; 6,600 cGy). Median follow-up period was U months. local control rates were calculated by Kaplan-Meier method. Generalized Wilcoxon test was used to evaluate the difference of control rates between comparable groups. Multivariate analysis using Cox proportional hazard model was done to find out prognostic factors affecting local control. Results:5 year survival rate of 37 patients was 89$\%$. Local control rate of 37 patients was 74$\%$ in 5 years. We included age, 7-stage, anterior commissure involvement, fraction size, total radiation dose, treatment time of radiotherapy as potential prognostic factors in univariate and multivariate analysis. As a result, treatment time had statistical significance in local control rate in both univariate (p=0.026) and multivariate (p=0.017) analysis. Complication was not recorded except one patient with hypothyroidism. Conclusion :This study revealed that overall treatment time of radiation was a significant factor affecting local control rate.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.277-282
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• 2000

Purpose : Though It has been known that the to tolerance of the liver to external beam irradiation depends on the irradiated volume and dose, few data exist which Quantify this dependence. However, recently, with the development of three dimensional (3-D) treatment planning, have the tools to Quantify the relationships between dose, volume, and normal tissue complications become available. The objective of this study is to investigate the relationships between normal tissue complication probabili쇼 (WCP) and the risk of radiation hepatitis for patients who received variant dose partial liver irradiation. Materials and Methods : From March 1992 to December 1994, 10 patients with hepatoma and 10 patients with bile duct cancer were included in this study. Eighteen patients had normal hepatic function, but 2 patients (prothrombin time 73$\%$, 68$\%$) had mild liver cirrhosis before irradiation. Radiation therapy was delivered with 10MV linear accelerator, 180$\~$200 cGy fraction per day. The total dose ranged from 3,960 cGy to 6,000 cGy (median dose 5,040 cGy). The normal tissue complication probability was calculated by using Lyman's model. Radiation hepatitis was defined as the development of anicteric elevation of alkaline phosphatase of at least two fold and non-malignant ascites in the absence of documented progressive. Results: The calculated NTCP ranged from 0.001 to 0.840 (median 0.05). Three of the 20 patients developed radiation hepatitis. The NTCP of the patients with radiation hepatitis were 0.390, 0.528, 0.844(median : 0.58$\pm$0.23), but that of the patients without radiation hepatitis ranged fro 0.001 to 0.308 (median .0.09$\pm$0.09). When the NTCP was calculated by using the volume factor of 0.32, a radiation hepatitis was observed only in patients with the NTCP value more than 0.39. By contrast, clinical results of evolving radiation hepatitis were not well correlated with NTCP value calculated when the volume factor of 0.69 was applied. On the basis of these observations, the volume factor of 0.32 was more correlated to predict a radiation hepatitis. Conclusion : The risk of radiation hepatitis was increased above the cut-off value. Therefore the NTCP seems to be used for predicting the radiation hepatitis.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.115-123
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• 2013

Stoker type incinerator is one of the most popular one used as municipal solid waste (MSW) incineration because, in general, it is quite suitable for large capacity and need no preprocessing facility. Nowadays, however, since the combustible portion of incoming MSW increases together with the decrease of the moisture content due to prohibition of directly burying food waste in landfill, the heating value of waste is remarkably increasing in comparison with the early stage of incinerator installation. Consequently, the increased heating value in incinerator operation causes a number of serious problems such as reduction of waste amount to be burned due to the boiler heat capacity together with the significant NO generation in high temperature environment. Therefore, in this study, a series of numerical simulation have been made as parameters of waste amount and the fraction of moisture in air stream in order to investigate optimal operating condition for the resolution of the problems associated with the high heating value of waste mentioned above. In specific, a detailed turbulent reaction flow field calculation with NO model was made for the full scale incinerator of D city. To this end, the injection method of moisturized air as oxidizer was intensively reviewed by the addition of moisture water amount from 10% and 20%. The calculation result, in general, showed that the reduction of maximum flame temperature appears consistently due to the combined effects of the increased specific heat of combustion air and vaporization heat by the addition of water moisture. As a consequence, the generation of NOx concentration was substantially reduced. Further, for the case of 20% moisture amount stream, the afterburner region is quite appropriate in temperature range for the operation of SNCR. This suggests the SNCR facility can be considered for reoperation. which is not in service at all due to the increased heating value of MSW.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.90-104
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• 2019

In this study, CALPUFF modeling was performed, using a real surface and upper air meterological data to predict trustworthy modeling-results. Pollutant-releases from windscreen chambers of enclosed poultry farms, P1 and P2, and from a open poultry farm, P3, and their diffusing behavior were modeled by CALPUFF modeling with volume sources as well as by finally-adjusted CALPUFF modeling where a linear velocity of upward-exit gas averaged with the weight of each directional-emitting area was applied as a model-linear velocity ($u^M_y$) at a stack, with point sources. In addition, based upon the scenario of poultry farm-releasing odor and particulate matter (PM) removal efficiencies of 0, 20, 50 and 80% or their corresponding emission rates of 100, 80, 50 and 20%, respectively, CALPUFF modeling was performed and concentrations of odor and PM were predicted at the region as a discrete receptor where civil complaints had been frequently filed. The predicted concentrations of ammonia, hydrogen sulfide, $PM_{2.5}$ and $PM_{10}$ were compared with those required to meet according to the offensive odor control law or the atmospheric environmental law. Subsequently their required removal efficiencies at poultry farms of P1, P2 and P3 were estimated. As a result, a priori assumption that pollutant concentrations at their discrete receptors are reduced by the same fraction as pollutant concentrations at P1, P2 and P3 as volume source or point source, were controlled and reduced, was proven applicable in this study. In case of volume source-adopted CALPUFF modeling, its required removal efficiencies of P1 compared with those of point source-adopted CALPUFF modeling, were predicted similar each other. However, In case of volume source-adopted CALPUFF modeling, its required removal efficiencies of both ammonia and $PM_{10}$ at not only P2 but also P3 were predicted higher than those of point source-adopted CALPUFF modeling. Nonetheless, the volume source-adopted CALPUFF modeling was preferred as a safe approach to resolve civil complaints. Accordingly, the required degrees of pollution prevention against ammonia, hydrogen sulfide, $PM_{2.5}$ and $PM_{10}$ at P1 and P2, were estimated in a proper manner.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.40-54
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• 2004

Purpose : Captopril (angiotension converting enzyme inhibitor) is known to have a radioproptective effect in the lungs, intestines and skin, but its effect in the heart is unclear. To investigate the radioprotectlve efiect and mechanism of captopril on the heart, the histopathological changes and immunohistochemical stains were compared with radiation alone, and radiation combined with captopril, in the rats. Materials and Methods : The histopathological changes and immunohistochemical stains ($TNF{\alpha}$, $TGF{\beta}1$, PDGF and FGF2) were examined in the radiation alone and the combined captopril and radiation groups, 2 and 8 weeks after irradiation. Each group consisted of 8 to 10 rats (Sprague-Dawley). Irradiation (12.5 Gy) was given to the left hemithorax in a single fraction. Captopril (50 mg/Kg/d) mixed with water, was given orally and continuously from the first week prior to, up to the 8th week of the experiment. Results : In the radiation alone group, the ventricle at 2 weeks after irradiation showed prominent edema (p=0.082) and fibrin deposit (p=0.018) compared to the control group. At 8 weeks, the edema was decreased and fibrosis increased compared to those at 2 weeks. The histopathological changes of the combined group were similar to those of the control group, due to the reduced radiation toxicity at 2 and 8 weeks. The endocardial fibrin deposit (p=0.047) in the atrium, and the interstitial fibrin deposit (p=0.019) and edema (p=0.042) of the ventricle were reduced significantly in the combined group compared to those in the radiation alone group at 2 weeks. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$, PDGF and FGF-2 in the radiation alone group were more increased than in the control group, especially in the pericardium and endocardium of the atrium at 2 weeks. At 8 weeks, the pericardial $TNF-{\alpha}$ and $TGF-{\beta}1$ in the radiation alone group continuously increased. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were decreased in the combined group at 2 weeks. At 8 weeks, the expressions of $TNF-{\alpha}$ in the atrial and ventricular pericardia were markedly reduced (p=0.049, p=0.009). Conclusion : This study revealed that the early heart damage induced by radiation can be reduced by the addition of captopril in a rat model. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were further decreased in the combined compared to the radiation alone group at both 2 and 8 weeks. From these results, it may be concluded that these cytokines probably play roles in the radioprotective mechanism of captopril from the radiation-induced heart toxicity, similarly to in other organs.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.8-17
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• 2006

Purpose : We describe the changes of rat glomerular epithelial cells when exposed to high levels of glucose and advanced glycosylation endproducts(AGE) in the in vitro diabetic condition. We expect morphological alteration of glomerular epithelial cells and permeability changes experimentally and we may correlate the results with a mechanism of proteinuria in DM. Methods : We made 0.2 M glucose-6-phsphate solution mixed with PBS(pH 7.4) containing 50 mg/mL BSA and pretense inhibitor for preparation of AGE. As control, we used BSA. We manufactured and symbolized five culture dishes as follows; B5 - normal glucose(5 mM) + BSA, B30 - high glucose(30 mM) + BSA, A5 - normal glucose(5 mM) + AGE, A30 - high glucose(30 mM) + AGE, A/B 25 - normal glucose(5 mM) + 25 mM of mannitol(osmotic control). After the incubation period of both two days and seven days, we measured the amount of heparan sulfate proteoglycan(HSPG) in each dish by ELISA and compared them with the B5 dish at 2nd and 7th incubation days. We observed the morphological changes of epithelial cells in each culture dish using scanning electron microscopy(SEM). We tried the permeability assay of glomerular epithelial cells using cellulose semi-permeable membrane measuring the amount of filtered BSA through the apical chamber for 2 hours by sandwich ELISA. Results : On the 2nd incubation day, there was no significant difference in the amount of HSPG between the 5 culture dishes. But on the 7th incubation day, the amount of HSPG increased by 10% compared with the B5 dish on the 2nd day except the A30 dish(P<0.05). Compared with the B5 dish on the 7th day the amount of HSPG in A30 and B30 dish decreased to 77.8% and 95.3% of baseline, respectively(P>0.05). In the osmotic control group (A/B 25) no significant correlation was observed. On the SEM, we could see the separated intercellular junction and fused microvilli of glomerular epithelial cells in the culture dishes where AGE was added. The permeability of BSA increased by 19% only in the A30 dish on the 7th day compared with B5 dish on the 7th day in the permeability assay(P<0.05). Conclusion: We observed not only the role of a high level of glucose and AGE in decreasing the production of HSPG of glomerular epithelial cells in vitro, but also their additive effect. However, the role of AGE is greater than that of glucose. These results seems to correlate with the defects in charge selective barrier. Morphological changes of the disruption of intercellular junction and fused microvilli of glomerular epithelial cells seem to correlate with the defects in size-selective barrier. Therefore, we can explain the increased permeability of glomerular epithelial units in the in vitro diabetic condition.