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Dose Distribution and Characterization for Radiation Fields of Multileaf Collimateor System (방사선 입체조형치료용 다엽콜리메이터의 특성과 조직내 선량분포 측정)

  • Chu, Sung-Sil;Kim, Gwi-Eon
    • Radiation Oncology Journal
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    • v.14 no.1
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    • pp.77-85
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    • 1996
  • Purpose : Multileaf collimator(MLC) is very suitable tool for conformal radio-therapy and commissioning measurements for a multileaf collimator installed on a dual energy accelerator with 6 and 10MV photons are required, For modeling the collimator with treament planning software, detailed dosimetric characterization of the multileaf collimator including the penumbra width, leaf transmission between leaf leakage and localization of the leaf ends and sides is an essential requirement. materials and Methods : Measurement of characteristic data of the MLC with 26 pair block leaves installed on CLINAC 2100C linear accelerator was performed. Low sensitive radiographic film(X-omatV) was used for the penumbra measurement and separate experiments using radiographic film and thermoluminescent dosimeters were performed to verify the dose distribution, Measured films were analized with a photodensitometer of WP700i scanner. Results : For 6 & 10 MV x-ray energies, approximately $2.0\%$ of photons incident on the multileaf collimator were transmitted and an additional $0.5\%$ leakage occurs between the leaves. Localizing the physical end of the leaves showed less than 1mm deviation from the $50\%$ decrement line and this difference is attributed to the curved shaped end on the leaves One side of a sin히e leaf corresponded to the $50\%$ decrement line, but the opposite face was aligned with a lower value. This difference is due to the tongue and groove used to decrease between leaf leakage. Alignment of the leaves to form a straight edge resulted larger penumbra at far position from isocenter as compare with divergent alloy blocks. When the MLC edge is stepped by sloping field, the isodose lines follow the leaf pattern and Produce scalloping isodose curves in tissue. The effective penumbra by 45 degree stepped MLC is about 10mm at 10cm depth for 6MV x-ray. The difference of effective penumbra in deep tissue between MLC and divergent alloy blocks is small (5mm). Conclusion : Using the characteristic data of MLC, the MLC has the clinlical acceptability and suitability for 3-D conformal radiotherapy except small field size.

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Accelerated Hyperfractionated Radiotherapy for Locally Advanced Uterine Cervix Cancers (국소진행된 자궁경부암에서의 가속과분할 방사선치료)

  • Seo, Young-Seok;Cho, Chul-Koo;Yoo, Seong-Yul;Kim, Mi-Sook;Yang, Kang-Mo;Yoo, Hyung-Jun;Choi, Chul-Won;Lee, Kyung-Hee;Lee, Eui-Don;Rhu, Sang-Young;Choi, Suck-Chul;Kim, Moon-Hong;Kim, Beob-Jong
    • Radiation Oncology Journal
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    • v.26 no.1
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    • pp.24-34
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    • 2008
  • Purpose: To assess the efficacy of the use of accelerated hyperfractionated radiotherapy(AHRT) for locally advanced uterine cervix cancers. Materials and Methods: Between May 2000 and September 2002, 179 patients were identified with FIGO stage IIB, IIIB, and IVA cancers. Of the 179 patients, 45 patients were treated with AHRT(AHRT group) and 134 patients were treated with conventional radiotherapy(CRT group), respectively. Patients undergoing the AHRT regimen received a dose of 30 Gy in 20 fractions(1.5 $Gy{\times}2$ fractions/day) to the whole pelvis. Subsequently, with a midline block, we administered a parametrial boost with a dose of 20 Gy using 2 Gy fractions. Patients also received two courses of low-dose-rate brachytherapy, up to a total dose of 85{\sim}90 Gy to point A. In the CRT group of patients, the total dose to point A was $85{\sim}90$ Gy. The overall treatment duration was a median of 37 and 66 days for patients that received AHRT and CRT, respectively. Statistical analysis was calculated by use of the Kaplan-Meier method, the log-rank test, and Chi-squared test. Results: For patients that received cisplatin-based concurrent chemotherapy and radiotherapy, the local control rate at 5 years was 100% and 79.2% for the AHRT and CRT group of patients, respectively(p=0.028). The 5-year survival rate for patients with a stage IIB bulky tumor was 82.6% and 62.1% for the AHRT group and CRT group, respectively(p=0.040). There was no statistically significant difference for severe late toxicity between the two groups(p=0.561). Conclusion: In this study, we observed that treatment with AHRT with concurrent chemotherapy allows a significant advantage of local control and survival for locally advanced uterine cervix cancers.

Effect of Pre-wilting on the Forage Quality of Organic Sorghum$\times$Sudangrass Silage (예건이 수수$\times$수단그라스 교잡종 유기 사일리지의 품질에 미치는 영향)

  • Lim, Hyun-Jin;Kim, Jong-Duk;Lee, Hyun-Jin;Jeon, Kyeong-Hup;Yang, Ka-Young;Kwon, Chan-Ho;Yoon, Sei-Hyung
    • Korean Journal of Organic Agriculture
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    • v.17 no.4
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    • pp.519-527
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    • 2009
  • The main nutritional problem of sorghum$\times$sudangrass hybrid silage is low quality and dry matter (DM) contents. This experiment was conducted to evaluate whether field pre-wilting treatment of sorghum$\times$sudangrass hybrid silage increases DM content and forage quality of the silage. The experiment was a randomized complete block design with three replications. The treatments were consisted of five different wilting days: 0 day (direct cut silage), 0.5 day, 1 day, 2 days and 3 days. Sorghum$\times$sudangrass hybrid silage with pre-wilting showed low 4.00 pH values, however direct cut silage (control) showed a 4.30 value because of its high moisture content. The DM content of sorghum$\times$sudangrass hybrid silage with pre-wilting was high above 25.1% after 1 days, however that of direct cut silage had 17.6%. And the effluent of wilted silage was decreased with prolonged wilting period, but that of direct cut silage produced effluent of 183 mL/kg. Crude protein and ether extract with wilted silage were decreased, however crude ash was increased with prolonged wilting period. Silage with pre-wilting had higher acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents than control silages, while its non-fiber carbohydrate (NFC) showed the opposite results. Lactic acid and total organic acid were increased with prolonged wilting period. For the palatability of dairy goat, silage with 2 days wilting was highest among silages. The experiment results indicate that wilted sorghum$\times$sudangrass hybrid silage could be recommended as effective method for reducing effluent, increasing pH and forage quality more than direct cut silage. Optimum pre-wilting day of sorghum$\times$sudangrass hybrid silage may be 1 days.

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Effects of Probiotics as an Alternative for Antibiotics on Growth Performance, Nutrient Digestibility, Noxious Gas Emission and Fecal Microbial Population in Growing Piglets (항생제 대체 생균제가 자돈의 생산성,영양소 이용률, 유해가스 발생량 및 분내 미생물 수에 미치는 영향)

  • Kim, Jong-Duk;Chung, Heung-Woo;Shim, Kum-Seob;Park, Seung-Young;Ju, Jong-Cheol;Song, Jae-Jun;Lee, Kyung-Ho;Park, Joong-Kook;Park, Do-Yun;Kim, Chang-Hyun
    • Korean Journal of Organic Agriculture
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    • v.18 no.4
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    • pp.527-539
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    • 2010
  • This study was conducted to determine the effect of probiotics as an alternative for antibiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in growing piglets. A total of 96 piglets ($22.5{\pm}1.3$kg average body weight) were allotted to 3 different treatment groups and replicated 4 times with 8 piglets per replicate in randomized complete block design. Treatments were T1) (Control, basal diet+0.2% antibiotics), T2) 0.2% probiotics complex and T3) 0.3% Bacillus probiotics. During the whole experiment period, there were no differences (p>0.05) in average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency. However, digestibility of dry matter, crude protein, ether extract, nitrogen free extract and crude ash were showed higher in probiotics groups (T2 and T3) than those of control. In noxious gas emission, ammonia, amine, hydrogen sulfide and mercaptan were significantly (p<0.05) reduced in T2 and T3 treatments compared to those in control. Moisture content of feces was not significantly different among treatments. The colony forming units (CFU) of total bacteria, E. coli and thermoduric bacteria in feces were significantly different among treatments. The CFU of total bacteria, E. coli and thermoduric bacteria in T3 treatment were reduced by feeding probiotics B. From this study, we suggest that probiotics A and B are likely able to improve the growth performance and nutrients digestibility, reduce noxious gas emission and change the fecal microbial composition in growing piglets.

Clinical Results According to the Level and Extent of Sympathicotomy in Essential Hyperhidrosis (본태성다한증에서 흥부교감신경의 차단 범위와 부위에 따른 임상결과)

  • 최순호;박권재;이삼윤
    • Journal of Chest Surgery
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    • v.35 no.2
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    • pp.127-132
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    • 2002
  • Video-assisted thoracic sympathicotomy is a safe and effective therapy for the treatment of essential hyperhidrosis with immediate symptomatic improvement. However, this is offset by the occurrence of a high rate of side effects, such as embarrassing compensatory hyperhidrosis. Therefore, by comparing and assessing the degree of symptomatic improvement or compensatory sweating following sympathicotomy at various levels and the extent of block, we are to determine the optimal level of sympathicotomy and which method will result in minimal side effects and maximal benefits. Material and Method: From January 1998 to June 2001, the thoracoscopic sympathicotomy was performed in 150 patients suffering from essential hyperhidrosis in the Dept. of Thoracic and Cardiovascular Surgery, Wonkwang University Hospital. The patients were divided into three groups. GroupI(n=50): patients having undergone 72,3,4 sympathicotomy, GroupII (n=50): patients having undergone 72 sympathicotomy which consist of blocking the interganglionic neural fiber on the second rib, and group 111(n=50): patients having undergone 73 sympathicotomy which consist of blocking the interganglionic neural fiber on the third rib. The parameters were composed of the satisfaction rate of treatment, the degree of compensatory sweating, postoperative complications, and changes of plantar sweating. Results: There was no difference in age and sex among the groups. All of the treated patients obtained satisfactory alleviation of essential hyperhidrosis in immediate postoperative period. However the rate of long-term satisfaction were 80%, 92%, and 96% in groupsI,II, and III respectively(p<0.05). More than embarrassing compensatory hyperhidrosis was present in 50%, 28%, and 18% in groups I,II ,and III respectively(p<0.05). Slight but comfortable amounts of palmar humidness was expressed in decreasing order, group III(34%), groupII(6%), and group I(4%) respectively(p<0.05). In regard to plantar sweating, decrease in sweating was expressed in each of the three groups, but was not significant between the groups.

Modified Blalock-Taussig Shunt in Neonates (신생아에서 변형 Blalock-Taussig 단락술)

  • 조광조;성시찬
    • Journal of Chest Surgery
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    • v.30 no.4
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    • pp.378-382
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    • 1997
  • To evaulate the effectiveness and risk factors for shunt failure of the Blalock-Taussig shunt in neonates, we analyzed the 21 neonates who were undergone Blalok-Taussig shunt operation at Dong-A University Hospital from December 1991 to Feburary 1996. We evaluated operative mortality, patency of the shunt. and distortion of pulmonary artery. We also determined the risk factors for the shunt failure. Age at operation was from 1 day to 30 days(mean 11.7 days). We ghts were 2.4 to 4.5kg(mean 3.1 kg). The underlying lesions included severe tetralogy of Fallot with pulmonary stenosls or atresia(N=11) and single ventricle varieties with. pulmonary stenosis or atresia(N=10). Prostaglandin El was given in 13 neonates prior to operation. The mean preoperative(prior to prostaglandin El therapy) and postoperative arterial oxygen tension were 30.1 mmHg and 46.3 mmHg respectively(P(0.01). The shunt was performed through a left thoracotomy in 11 patients and through a right thoracotomy In 10. A 5 mm graft was used in 15 patients and a 4 mm graft in 6 patients. The incidence of early shunt occlusion was 9.5%(2 patients). The hospital mortality was 9.5%(2 patients with early shunt occlusion). Univariate analysis revealed that body weight of 2.6 kg or less(p=0.021), pulmonary artery size of 3mm or less(p=0.008), and 4 mm graft (p=0.021) were risk factors predictive of early shunt failure. The patency rate of the shunt in hospital survivors was 100% at mean ollow-up of ll.3 months(There was not death or reoperation related to shunt failure). 10 patients were catheterized during postoperative follow-up. There was no significant distorsion of pulmonary artery. So we concluded that the modified Blalock-Taussig shunt in neonates was excellent in the hospital survivors.

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Arrhythmia Surgery in Fontan Operation (폰탄 수술에서의 부정맥수술)

  • 임홍국;한국남;김웅한;이정렬;노준량;김용진
    • Journal of Chest Surgery
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    • v.37 no.8
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    • pp.644-651
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    • 2004
  • Background: Refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We reviewed our experience with arrhythmia surgery in patients who had Fontan operation. Material and Method: Between July 1986 and December 2003, 275 early survivors after Fontan operation were reviewed. Fourteen patients underwent. arrhythmia surgery at reoperation after Fontan operation, and mean age at reoperation was 16.8$\pm$7.1 (range: 4.5 ∼ 30.6) years. Mechanisms of arrhythmia included atrial flutter in 8 patients, and atrial fibrillation in 2. Arrhythmia surgery has evolved from isthmus cryoablation in 12 patients to right-sided maze in 2 patients. Thirty-two patients. underwent prophylactic isthmus cryoablation concomitantly at initial Fontan operation. Result: Postoperative arrhythmias occurred in 68 patients (24.7%) among 275. There was no early and late mortality after the arrhythmia surgery. After redo Fontan operation, all patients maintained normal sinus rhythm. Atrial flutter recurred in 3 patients who had sinus conversion with medication and 7 required permanent pacemakers with a mean follow-up of 26.5$\pm$29.1 (range: 2 ∼ 73) months. All patients have improved to NYHA class I or II. After prophylactic cryoablation at initial Fontan operation, 29 patients (90.6%) had sinus rhythm, 1 patient had junctional tachycardia, 1 patient had sinus nodal dysfunction, and 1 patient had AV block with a mean follow-up of 51.3$\pm$19.8 (range: 4∼80) months. Conclusion: Redo Fontan operation, and concomitant arrhythmia surgery reduced atrial arrhythmias and improved NYHA functional classification.

Effect of Acute and Chronic Treatment with Risperidone on the Serotonin and Dopamine Receptors in the Rat Brain (Risperidone의 급성 및 만성 투여가 흰쥐 뇌의 Serotonin과 Dopamine 수용체에 미치는 영향)

  • Choi, Yun-Young;Son, Hye-Kyung;Kim, Chang-Yoon;Lee, Chul;Lee, Hee-Kyung;Moon, Dae-Hyuk
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.1
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    • pp.9-18
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    • 1997
  • The therapeutic efficacy of antipsychotic drugs is generally attributed to their ability to block dopamine $D_2$ receptors. Classical $D_2$ antagonists are not effective to treat negative symptoms and produce extrapyramidal side effects On the other hand, atypical antipsychotic agents ameliorate negative symptoms without producing extra-pyramidal side effects, and it is reported to be associated with blockade of serotonin $5-HT_2$ receptors. The purpose of this study was to evaluate the effect of risperidone on neuroreceptors in the rat brain by Quantitative autoradiography method. In acute treatment group, risperidone was injected into Peritoneal cavity of male Wistar rats with dose of 0, 0.1, 0.25, 0.5, 1.0 and 2.0mg/kg in each group(5/group), and they were decapitated after 2 hours. In chronic treatment group, risperidone was injected with dose of 0, 0.1, and 1mg/kg(I.P.) for 21 days and decapitated after 24 hours following last treatment. The effect of risperodone on the binding of [$^3H$]spiperone to $5-HT_2$ and $D_2$ receptors were analysed in 4 discrete regions of the striatum, nucleus accumbens, and frontal cortex by quantitative autoradiography Acute treatment with risperidone reduced cortical $5-HT_2$ specific [$^3H$]spiperone binding to 32% of vehicle-treated control. Subcortical $5-HT_2$ specific [$^3H$]spiperone binding was not affected at all dose groups whereas a significant reduction (57%) in $D_2$ specific [$^3H$]spiperone binding was observed in risperidone treated group at doses of 1-2mg/kg. Chronic treatment with risperidone produced a decrease in the maximal number of cortical $5-HT_2$ receptors to 51% and 46% of control in 0.1mg/kg & 1mg/kg treated group respectively. In conclusion, risperidone is a cortical serotonin receptor antagonist with relatively weak antagonistic action on dopamine receptors. These effects oil neuroreceptors may explain the therapeutic effect of risperidone as a atypical antipsychotic agents.

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Effect of Grass Filter Strips on PO4-P and Soil Loss in Runoff from Forage Cropland (사료작물 재배지에서 초지식생대가 PO4-P 및 토양유실 저감에 미치는 영향)

  • Jo, Nam-Chul;Yoon, Sei-Hyung;Kim, Ki-Young;Lee, Ki-Won;Kim, Meng-Jung;Yook, Wan-Bang;Jung, Min-Woong
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.30 no.4
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    • pp.309-316
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    • 2010
  • The performance of grass filter strips (GFS) in reducing $PO_4$-P concentrations and soil loss from the forage cropland was tested in an experiment on the 10% slope in Grassland and Forages Division, National Institute of Animal Science, Rural Development Administration (RDA) from October 2007 to September 2009. Forage cropland with rye-corn double cropping system receiving inorganic fertilizer or livestock manure (LM) were compared in a natural condition. The plots were hydrologically isolated in a randomized block layout of 3 treatments $\times$ 2 factors $\times$ 3 replicates. Main plots consisted of the length of GFS, such as $25\;m^2$ ($5{\times}5\;m$), $50m^2$ ($5{\times}10\;m$), $75m^2$ ($5{\times}15\;m$). Sub plots consisted of the type of LM, such as chemical fertilizer (CF), cattle manure (CM) and swine manure (SM). Concentrations of $PO_4$-P in surface runoff water were reduced as the length of GFS increased. Especially, GFS with 10 m and 15 m reduced $PO_4$-P concentrations significantly compared to that with 0 m (p<0.05). However, there was not significant different between $PO_4$-P concentrations of GFS with 10m and that of GFS with 15 m. Moreover, Soil loss in surface runoff water were reduced as the length of GFS increased. GFS with 15 m reduced soil loss significantly compared to that with 5 m and 10 m (p<0.05). The results from this study suggest GFS improve the removal and trapping $PO_4$-P and soil loss from forage cropland.

Effect of Seeding Rates of Cold Tolerant Italian Ryegrass Varieties on Those Seed Production (내한성 이탈리안 라이그라스 품종별 파종량이 종자생산에 미치는 영향)

  • Kim, Meing-Jooung;Seo, Sung;Kim, Jong-Geun;Choi, Ki-Jun;Kim, Ki-Yong;Lee, Sang-Hoon;Chang, Sun-Sik;Kim, Tae-Il;Kwon, Eung-Gi;Jeon, Byoung-Soo;Choi, Ki-Choon
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.30 no.3
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    • pp.247-256
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    • 2010
  • This experiment was carried out to investigate the effect of seeding rate of newly developed Italian ryegrass varieties, "Kogreen" and "Hwasan 101", on those seed production in Cheonan for three years (2005 to 2007). Two Italian ryegrass varieties were seeded at experimental fields of Grassland and Forage Division, National Institute of Animal Science on late September, and harvested at seed shattering stage. The experiment was arranged in randomized complete block design with three replications by each variety. The treatments was consisted of five seeding rates (5, 10, 20, 30, 40 kg/ha). The average heading date of "Kogreen" was 9 May and "Hwasan 101" was 25 May. The harvesting date of "Kogreen" was on 16 June when the rainy season should not set in. In the case of "Hwasan 101", the harvesting date of seed production was 3 July, because of rainy season. The number of ear per square meter, ear length, spikelet number, seed yield per ha and ripening rate of "Hwasan 101" were 471, 28.5 cm, 24.8, 1,631 kg and 71%, respectively. and those of "Kogreen" were 633, 24.0 cm, 20.8, 2,676 kg and 82.1%, respectively. The shattering property rate of "Hwasan 101" 40.3% was higher than that of "Kogreen" 2.6%. The germination rate of harvested "Hwasan 101" seed was 81.8% and that of "Kogreen" was 79.4%, respectively. In conclusion, the optimum seeding rate of Italian ryegrass for seed production are recommended 20kg/ha in both "Hwasan 101" and "Kogreen".