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Pulmonary Hypertension Secondary to Bronchopulmonary Dysplasia in Very Low Birth Weight Infants (<1,500 g) (기관지 폐 이형성증을 가진 극소 저체중 출생아에서 폐고혈압증)

  • Yoo, Hye-Soo;Kim, Myo-Jing;Kang, Ji-Man;Lee, Cha-Gon;Kim, Jin-Kyu;Ahn, So-Yoon;Kim, Eun-Sun;Huh, June;Chang, Yun-Sil;Kang, I-Seok;Park, Won-Soon;Lee, Heung-Jae
    • Neonatal Medicine
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    • v.18 no.1
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    • pp.96-103
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    • 2011
  • Purpose: Although infants with bronchopulmonary dysplasia (BPD) are at risk of developing secondary pulmonary hypertension (PH), which is associated with significant morbidity and mortality, little has been reported about the incidence, clinical course and prognosis of PH secondary to BPD in premature infants. This study was done to investigate the incidence, risk factors, clinical course, and the ultimate prognosis of PH developed secondary to BPD in very low birth weight infants (<1,500 g). Methods: Medical records of very low birth weight infant (VLBWI) admitted to Samsung Medical Center NICU from January 2000 to July 2007 were reviewed retrospectively. BPD was defined by Jobe's classification. The diagnosis of pulmonary hypertension was established as velocity of tricuspid valve regurgitation (TR) ${\geq}$3 m/s and a flattening of the intraventricular septum by conducting Doppler echocardiography. Results: The incidence of pulmonary hypertension was 6% in VLBWI with BPD and it developed in moderate to severe BPD. The diagnosis of pulmonary hypertension was made on postnatal 133 days (range 40-224 days) and the risk factors related to developing pulmonary hypertension were severe BPD, small for gestational age and outborn infants. The mortality rate was 57% and especially higher in severe BPD (70%). The time to recovery spent 3 months (range 1-10 months) in survived patients. Conclusion: Based on the results of this research, pulmonary hypertension secondary to BPD in VLBWI related to severity of BPD and had a poor prognosis. We expect that regular long-term echocardiography may be helpful in treating reversible in VLBWI with moderate to severe BPD.

Total Spinal Block and Cortical Epidural Block for Whiplash Syndrome and Reflex Sympathetic Dystrophy (Report of Four Cases) (전척수(全脊髓) 및 경막외차단(硬膜外遮斷)으로 편타성(鞭打性) 손상(損傷)의 통증치험(痛症治驗) (4례(例) 보고(報告)))

  • Park, Wook;Ok, See-Young;Song, Hoo-Bin
    • The Korean Journal of Pain
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    • v.1 no.1
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    • pp.106-119
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    • 1988
  • For the relief of pain in 3 cases of whiplash syndromes (case I, II and IV) and in one of reflex sympathetic dystrophy (case III), we have carried out six intentional. total spinal blocks (TSB) which attempted two times in case I, three in case II and one in carte III whoso various symptoms were chronically unresponsive to the usual conservative treatments, and a time of cervical epidural and right suprascapular nerve block in case W whose acute symptom lasted 4 drys following the cervical injury (see fables from 1 to 9). During the 753, we have observed clinically the sequential charges of respiration, lid and pupil reflexes, body motion and consciousness. And checked the blood pressure, pulse rate and arterial Pco2. The effectiveness of those blocks has been assessed by using the Visual Analog Scale which is designed to measure the patient$\acute{s}$ subjective intensity of pain and also we have found out the sequelae following those blocks. The methods of the blocks were as the following: 1. Under the N.P.O. for 8~10 hours, the preparations of immediate cardiopulmonary resuscitation and premedication with atropine 0.5mg at thirty minutes before the TSB, it was performed by injecting the mixture of 2% mepivacaine 10 or 15ml and normal saline 10 or 5ml through No. 23 G. spinal needle into the subarachnoid space of $C_7-T_1$ interspinous region with fully flexed neck on the lateral posture. Immediately after the injection of the local anesthetic in the lateral position, the patient$\acute{s}$ were hasten to change Trendelenburg$\acute{s}$ position in order to act the drugs cephalad and to make easy controlled respiration with oxygen. 2. The cervical epidural block was done by injecting the mixture of 0.5% bupivacaine 4ml, normal saline 4ml and triamcinolone 15mg through No. 18 G. Tuohy needle into the epidural space on the same region and posture as the above without premedication.7he suprascapular nerve block was done by injecting of 0.5% bupivacaine 3ml only into the right suprascapular fossa on the sitting posture. The results were as the following: 1. The cessation of respiration was seen within 5 minutes following the subarachnoidal injection of the above 20ml mixture in 2 to 3 minutes and then soon the consciousness began to disappear. The loss of Lid and pupil reflexes noted between 5 to 10 minutes and the size of the dilated pupils was equal between 5 to 20 minutes, but the pupil of the dependent side on tile lateral position was dilated 1 to 3 minutes earlier than that of the independent. The patients had r=ever responded to any stimulations during the TSB except their heart funtion. 2. The recovery of the TSB was as the following, firstly the ankle and lower limb of the independent side began to move slightly with in 34 to 75 minutes after the injection and then that of the dependent Secondly the neck and upper limb moved 6 to 15 minutes later than the lower limb. Thirdly the self respiration began to appear between 40 to 80 minutes from the block. The lid and pupil reacted to touch and light respectively between 40 to 80 minutes but the pupil of the independent side responded earlier than that of the depends. Lastly the consciousness recovered completely between 80 to 125 minutes from the block. 3. In the cardiopulmonary function during the TSB, the blood pressure were stable except the 210/130 tory at the and block of case I. There were bradycardias between 65 to 85 minutes in case I and II but no arrythmia on the EKG. The level of the arterial Pco2 was maintained to 43~45 torr during the TSB. 4. The effectiveness of the above blocks was no pain(0%) in case IV, and light (10~20%) in case I and II but no improvement in case III. 5. The right arm weakness has been complicated as to be Injected accidently the "COLD" local anesthetic at the End block of case I.

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In Vivo Embryo Production and Embryo Transfer in Hanwoo and Jeju Black Cattle Using CIDR (CIDR를 이용한 제주 한우 및 흑우의 체내 수정란 생산과 이식)

  • Kim, Y.H.;Koo, J.C.;Oh, C.W.;Kang, S.Y.;Yang, B.S.;Oh, S.J.;Kim, C.N.;Song, J.Y.;Kim, I.H.
    • Journal of Embryo Transfer
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    • v.21 no.3
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    • pp.191-198
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    • 2006
  • The objectives of this study was to produce valuable offsprings of Hanwoo and Jeju black cattle using in vivo embryo production and embryo transfer techniques during 5 years ($2001{\sim}2005$) in Jeju. Two hundred and eighty six Hanwoo and sixty nine Jeju black cattles, at random stages of the estrous cycle, received a CIDR. Seven days later, the animals were superovulated with a total of 400 mg pFSH ($Folltropin^{(R)}-V$) administered twice daily in constant doses (each 50 mg) over 4 days. On the 6th administration of FSH, CIDR was withdrawn and 25 mg $PGF_{2{\alpha}}$ was administered. Cows were artificially inseminated thrice after estrous detection at 12 hr intervals. The cows received $250{\mu}g$ GnRH at the time of 2nd insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Recipients were synchronized with donors by insertion of a CIDR for 7 days and administration of 25 mg $PGF_{2{\alpha}}$ at the time of CIDR removal. The collected embryos were transferred to 1,219 recipients by 6 transfer persons. The mean numbers of total ova and transferable embryos from Hanwoo and Jeju black cattle donors were 7.4 and 4.7, respectively The number of transferable embryos differed between Hanwoo (5.0) and Jeju black cattle (3.5, p<0.05), while that of total ova did not differ. Repeated superovulation treatments decreased (p<0.05) the ratio of numbers of the flushed animals vs. superovulated animals in Jeju black cattle, and the numbers of total ova and transferable embryos in Hanwoo. More transferable embryos were collected at summer (5.6) than winter (2.9, p<0.01). The mean pregnancy rate was 40%. The pregnancy.ate was affected by transfer year (2001<2004, p<0.05) and transfer person ($33.0{\sim}41.9%$, p<0.01), while not by donor (embryo) breed. These results showed that in vivo embryo preduction and embryo transfer techniques using CIDR for Hanwoo and Jeju black cattle donors as well as recipient, regardless of their estrous cycle, may enable a stable embryo production and recipient preparation.

A COMPARISON OF THE SEDATIVE EFFECT ON CHLORAL HYDRATE DOSAGE IN THE SEDATION OF THE PEDIATRIC DENTAL PATIENTS (소아환자 진정요법에서 chloral hydrate의 용량에 따른 진정효과에 관한 연구)

  • Rho, Seung-Chul;Kim, Young-Jae;Jang, Ki-Taeg;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.32 no.3
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    • pp.517-524
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    • 2005
  • Despite the widespread use of chloral hydrate with hydroxyzine in the sedation of children, there is little agreement among pediatric dentists regarding its therapeutic dosage for the management of very uncooperative young children. Also, increasing concern has been raised with respect to its frequent failure to provide adequate levels of sedation when used according to the manufacturer's recommended dosage. Therefore, there has been many suggestions with respect to sedative effectiveness and safety of varying drug dosage, and some pediatric dental articles have advocated dosages exceeding manufacturer's recommendations. This study was performed to compare the effectiveness and safety in behavior management of the manufacturer's recommended dose of chloral hydrate(50mg/kg) with those of a higher dose(70mg/kg) used together with hydroxyzine(2mg/kg) and nitrous oxide(50%) when young children were sedated for dental treatment. The following results were obtained; 1. II group(70mg/kg) displayed higher mean score compared to I group(50mg/kg) with regard to the degree of sleep, crying, movement and overall behavior. The difference was statistically significant(p<0.05). 2. In comparison of success rates for sedation between the two groups, I group and II group showed 38.7% and 71.0% success rates respectively. An analysis of variance was statistically significant(p<0.05). 3. Comparing the occurrence rate hypoxia between the two groups, there were 22.6% and 19.4% occurrence of hypoxia in I group and II group. An analysis of variance was not statistically significant(p>0.05).

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Several causes of non virus-induced mosaic symptom on potato leaves and its induction by herbicides (감자 이상모자이크증상의 몇 가지 발생원인 및 제초제에 의한 증상 유기)

  • Kwon, Min;Hahm, Young-Il;Kim, Hyun-Jun;Yiem, Myoung-Soon
    • The Korean Journal of Pesticide Science
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    • v.5 no.2
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    • pp.45-50
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    • 2001
  • In recent, non virus-induced mosaic symptoms(NVMS) on potato leaves were observed in the seed potato fields, and its incidence rate was $5{\sim}20%$ nationwide. It made difficult to rogue out virus-infected plants, and caused much arguments between seed potato production farmers and seed potato inspectors. The objectives of these experiments were to find out the causes of NVMS, and also to induce mosaic symptom(phytotoxicity) on potato plants by treatment of several herbicides. No significant correlations were found between incidence rates of NVMS and values from soil analyses; soil pH, soil EC, organic matter content, and contents of inorganic constituents($P_2O_5,\;NO_3$, Ca, Mg, K) in the soil around the potato planted. The examinations by ELISA, virus indicator plants, and TEM showed that NVMS on potato leaves was not caused by the viruses infection. But, the use of herbicides could induced the NVMS on potato leaves. The incidence rates of potato treated with pendimethalin linuron of 400 mL/10 a, pendimethalin of 200 mL/10 a, pendimethalin.oxadiazon of 300 mL/10 a, and control were 61.1%, 47.2%, 19.4%, and 1.4%, respectively. Based on these results, we confirmed that the treatment of pendimethalin alone and in mixture with other herbicides were the reason of NVMS on potato leaves. The yields among test plots were similar except dicamba treated plot, which decreased by about 23% compared to control plot. When their progenies harvested in 1999 were planted in the following season, no symptoms of mosaic were observed.

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Ground Security Activities for Prevention of Aviation Terrorism -Centered on San Francisco International Airport of the U.S.A.- (항공테러방지를 위한 지상 보안활동 -미국 샌프란시스코국제공항을 중심으로-)

  • Kang, Maeng-Jin;Kang, Jae-Won
    • The Journal of the Korea Contents Association
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    • v.8 no.2
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    • pp.195-204
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    • 2008
  • With the growth of airline management, as well as computer and IT security, the international trade in this modern society has been rapidly increasing, Along with the advancing, airplanes have become a universal means of communication. However, the complications associated with airplane safety have also been brought up as a result, the most concerning of which is terrorism. One of the main counterplans for preventing terrorism is Ground security activities the core of Ground security activities is absolute safety for passengers in both passenger terminal and freight terminal. Subastral security refers to physical protection, proximity control and 100% security search and freight guarding of the passengers' possessions, and the personnel's duties to perform such jobs are be! coming more crucial. On the other hand, Airport security check has bee n gradually developing since the 1960's, when hijacking began to take place. Although the airports have been providing more safe and comfortable services to their customers, terrorism is still happening today. When Ground security activities is minute, the users feel displeasure and discomfort, yet considering solely their convenience can brings problems in achieving safety. Since the 9.11 terror in 2001, the idea of improving and strengthening airport security was reinforced and a considerable amount of estate is being spent today for invention and application of new technology. Various nations, including the United States, have been improving their systems of security through public services; public police department is actively carrying out their duties in airports as well. In San Francisco International Airport, private police department is in charge of collection of data, national events, VIP protection, law enforcement, cooperation within facilities, daily-based patrol and traffic control. Under guidance and supervision of national organizations, such as TSA, general police department interprets X-Rays, operates metal detectors, checks passports or IDs and observes reactions to explosives. Under these circumstances, studies about advancement of cooperation and duties of general police department and private police department necessitated: especially about private police department and their training for searching equipments, decrease in number of turn over rate, invention of technology and prior settlement in estate for security. The privacy of the public, who make up the major population of airport passengers, must also be minimized. In the following research, the activities of police departments in San Francisco International Airport will be analyzed in order to understand recent actions of the United States on airport security.

An Analysis of School Life Sensibility of Students at Korea National College of Agriculture and Fisheries Using Unstructured Data Mining(1) (비정형 데이터 마이닝을 활용한 한국농수산대학 재학생의 학교생활 감성 분석(1))

  • Joo, J.S.;Lee, S.Y.;Kim, J.S.;Song, C.Y.;Shin, Y.K.;Park, N.B.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.21 no.1
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    • pp.99-114
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    • 2019
  • In this study we examined the preferences of eight college living factors for students at Korea National College of Agriculture and Fisheries(KNCAF). Analytical techniques of unstructured data used opinion mining and text mining techniques, and the analysis results of text mining were visualized as word cloud. The college life factors included eight topics that were closely related to students: 'my present', 'my 10 years later', 'friendship', 'college festival', 'student restaurant', 'college dormitory', 'KNCAF', and 'long-term field practice'. In the text submitted by the students, we have established a dictionary of positive words and negative words to evaluate the preference by classifying the emotions of positive and negative. As a result, KNCAF students showed more than 85% positive emotions about the theme of 'student restaurant' and 'friendship'. But students' positive feelings about 'long-term field practice' and 'college dormitory' showed the lowest satisfaction rate of not exceeding 60%. The rest of the topics showed satisfaction of 69.3~74.2%. The gender differences showed that the positive emotions of male students were high in the topics of 'my present', 'my 10 years later', 'friendship', 'college dormitory' and 'long-term field practice'. And those of female were high in 'college festival', 'student restaurant' and 'KNCAF'. In addition, using text mining technique, the main words of positive and negative words were extracted, and word cloud was created to visualize the results.

Studies on the morphological variation of plant organs of elongating node-part in rice plant (수도 신장 절위 경엽의 형태변이에 관한 연구)

  • 김만수
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.5 no.1
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    • pp.1-35
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    • 1969
  • Attempts were made to obtain the fundamental knowledge on the quantitative constitution status of leaves and stem of elongating node-part, and the relationships between these morphological characteristics along with the nitrogen contents of leaves and grain yield were examined varing application amounts of nitrogen in rice plant. I. The agronomic characteristics of leaves and nodes of elongation node-part (4-node parts from the top of stem) were observed at heading stage with 20 leading rice varieties of Kang Won district. The results are summarized as follows: 1. Leaf area magnitude of the flag and the fourth leaf was smaller than that of the second and the third with the average value of flag leaf 18.61 $cm^2$, the second leaf 21.84 $cm^2$, the third 21.52 $cm^2$ and the fourth 18.56 $cm^2$. The weight of leaf blade showed an isotonic tendency with the magnitude of leaf area with the value of the flag leaf 97.0 mg, the second leaf 117.1 mg, the third 115.4 mg, and the fourth 95.3 mg. The weight of each leaf sheath was remarkably larger at the higher node-part than at the lower node-part of the stem with the value of flag leaf sheath 176.3 mg, the second 163.7 mg, the third 163.4 mg and the fourth 123.9 mg. Accordingly, the total leaf weight of each part was larger at the second and the third leaf than at the first and the fourth. Total plant weight of each part (weight of leaf blade, leaf sheath, and culm) also was larger at the middle node-part. 2. Coefficients of variation for the varietal differences of the morphological characteristics of elongating node-part were 12.75% for the leaf area, 15.29% for the weight of leaf blade, 15.90%, for the weight of leaf sheath, 11.42% for the weight of internode, 15.45% for the leaf weight (leaf blade & leaf sheath) and 13.24% for the straw weight. And these coefficient values of the most characteristics were, on the whole, smaller at the second and the third node-part than at the first and the fourth node-part, but the coefficient value of the internode weight was rather small at the third and fourth node-part. 3. Constitutional ratio of each plant organ to the total plant weight in term of dry matter weight (excluding head and root wight) was 39.2% for the leaf sheath, 34.2% for the culm, 26.6% for the leaf blade. And ocnstitutional ratio of leaf sheath in term of dry matter weight was larger at the higher position in contrast with that of culm. 4. Average weight ration of leaf blade to culm, leaf sheath to culm, leaf blades to sheath and the leaf blades to culm plus leaf sheath were 77.7 %, 114.5%, 67.9% and 36.2%, respectively. With regard to the position of the plant organ, the weight ratio of leaf blade to culm and that of leaf sheath to culm were larger at higher part in contrast with that of leaf blade to leaf sheath. 5. Generally, there founded deep relationships between grain yield and each morphological characteristics of plant organ of elongating node-part as follows; Correlation coefficient between total area of 4 leaves (from flag to the fourth leaf) and grain yield was ${\gamma}$=0.666$^{**}$ In regard to the position of leaves, correlation coefficient values of flag, the second, the third and the fourth leaf were ${\gamma}$=0.659$^{**}$, ${\gamma}$=0.609$^{**}$, ${\gamma}$=0.464$^{*}$ and ${\gamma}$=0.523$^{*}$, respectively. Correlation coefficient between total weight of leaf blades and the grain yield was ${\gamma}$=0.678$^{**}$. In regard to the position of leaves, that of flag leaf was ${\gamma}$=0.691$^{**}$, and ${\gamma}$=0.654$^{**}$ for the second leaf, ${\gamma}$=0.570$^{**}$ for the third, and ${\gamma}$=0.544$^{**}$ for the fourth. Correlation between the weight of leaves (blade weight plus sheath weight) and the grain yield showed similar values. In the relationship between plant weight and grain yield there also was significant correlation, but with highly significant value only for the first node-part. There appeared correlation between total weight of leaf sheath and grain yield with the value of ${\gamma}$=0.572$^{**}$ and in regard to the position of each leaf sheath the values were ${\gamma}$=0.623$^{**}$ for the flag leaf, ${\gamma}$=0.486$^{**}$ for the second leaf, ${\gamma}$=0.513$^{**}$ for the third, ${\gamma}$=0.450$^{**}$ for the fourth. However, there was no significant correlation between culm weight and grain yield. 6. With respect to in gain yield, varietal differences in magnitude of leaf area, weight of leaf blade, leaf weight per unit area, weight of leaf sheath, culm weight, total leaf and stem weight were larger in the case of high yielding varieties and decreased in accordance with decreasing yield. And this tendency also was shown in the varietal differences of magnitude of each part. Variation in magnitude of each part for the leaf area, weight of leaf blade, culm weight was significantly small in high yielding varieties compared to low yielding varieties. 7. Plant constitutional ratio of each organ of the elongating node-part in term of weight magnitnde varied to som extent according to varieties indicating leaf blade 27.6%, leaf sheath 39.5%, culm 32.9% in the case of high yielding varieties, leaf blade 25.5%, leaf sheath 38.1%, culm 36.4% in the case of low yielding varieties, and medium yielding varieties showed intermadiate values. 8. Far higher values of the weight ration of leaf blade to culm and leaf sheath to culm were given to the high yielding varieties compared to low yielding varieties. And medium yielding varieties showed intermadiate values. II. Effects of application rate of nitrogen on the morphological characteristics of the elongating node-part, nitrogen content of leaf blade, and their relation with the grain yield of the rice were observed with 3 rice varieties; Shin No.2, Shirogane, and Jinheung varying application amounts of nitrogen as 8kg, 12kg and 16kg per 10 are. 1. As for the variation of morphological magnitude s affected by the amounts of nitrogen application, total leaf area (4 leaves from the flag leaf) increased to 16.5% at 12kg N plot, and about 30% at 16kg N polt compared to 8kg N plot and total weight of leaf blade also increased to similar extent, respectively, in contrast with weight of leaf sheath increasing 4.9% and 7.8%, respectively. However, the weight of culm decreased to 1.5% and 11.2%at the 12kg N plot and 16kg N plot, respectively, and these decreasing rate was noted at the nodes of lower part. 2. As for the verietal differences in variation of morphological magnitude as affected by the amount of nitrogen fertilization, leaf area coefficient value of variation of the total leaf area was 15.40% for Shin No. 2, 12.87% for Shirogane, and 10.99% for Jinheung. With respect to the position of nodes, the largest variation of leaf blade magnitude was observed at the fourth for Shin No. 2, the second for Shirogan, and flag leaf for Jinheung. And there also was an isotonic varietal difference in the weight of leaf blade. Variation in total culm weight showed varietal differences with the coefficient value of 7.72% for Shin No.2, 12.11% for Shirogane, and 0.94% for Jinheung. There also was varietal differences in the variation according to the position of nodes. 3. Variation of each elongating node-part related to the fertilization amount decreased with the increase of fertilization amount in the items of leaf area, weight of leaf sheath, culm weight, but weight of leaf sheath varied more at heavier fertilization than at others. 4. Constitutional ratio of each organ excluding head also varied with fertilization amount; constitutional ratio of leaf blade increased much with the increasing amount of fertilization in contrast with the response of culm eight. However, constitutional ration of the weight of leaf sheath was not much affected. 5. Lower value of the ration of leaf blade to culm was given to the 8kg N per 10 are plot, and the ratio of leaf blade to leaf sheath decreased with the increasing amount of fertilization in contrast with the increase in the ratio of leaf sheath to culm. however, the ration of leaf blade to culm plus leaf sheath decreased. 6. With the increase of nitrogen fertilization, leaf area, weight of leaf blade and leaf sheath increased. Accordingly, grin yield also increased to some extent. It was noted that culm weight was changed inversely to the changes in grain yield, but the degree of this variation varied with varietal characteristics. 7. Nitrogen content of leaves at heading and fruiting stage varied with the fertilization amount, and average nitrogen content of leaves of the varieties used 2.19%, 2.49% and 2.74% at the plot of 8kg N, and 12kg N and 16kg N per 10 are, respectively, at heading time, and 0.80%, 0.92% and 1.03% at each plot at fruiting stage. Thus, nitrogen content of leaves increased much with the increasing amount of fertilization, and higher value was given to the leaves on the higher position of elongating node-part. 8. There also was variation of nitrogen content of leaves in accordance with the varieties. However higher grain yield was obtained from the plants retaining higher nitrogen content in leaves at heading or fruiting stage.

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Dosimetry of the Low Fluence Fast Neutron Beams for Boron Neutron Capture Therapy (붕소-중성자 포획치료를 위한 미세 속중성자 선량 특성 연구)

  • Lee, Dong-Han;Ji, Young-Hoon;Lee, Dong-Hoon;Park, Hyun-Joo;Lee, Suk;Lee, Kyung-Hoo;Suh, So-Heigh;Kim, Mi-Sook;Cho, Chul-Koo;Yoo, Seong-Yul;Yu, Hyung-Jun;Gwak, Ho-Shin;Rhee, Chang-Hun
    • Radiation Oncology Journal
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    • v.19 no.1
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    • pp.66-73
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    • 2001
  • Purpose : For the research of Boron Neutron Capture Therapy (BNCT), fast neutrons generated from the MC-50 cyclotron with maximum energy of 34.4 MeV in Korea Cancer Center Hospital were moderated by 70 cm paraffin and then the dose characteristics were investigated. Using these results, we hope to establish the protocol about dose measurement of epi-thermal neutron, to make a basis of dose characteristic of epi-thermal neutron emitted from nuclear reactor, and to find feasibility about accelerator-based BNCT. Method and Materials : For measuring the absorbed dose and dose distribution of fast neutron beams, we used Unidos 10005 (PTW, Germany) electrometer and IC-17 (Far West, USA), IC-18, ElC-1 ion chambers manufactured by A-150 plastic and used IC-l7M ion chamber manufactured by magnesium for gamma dose. There chambers were flushed with tissue equivalent gas and argon gas and then the flow rate was S co per minute. Using Monte Carlo N-Particle (MCNP) code, transport program in mixed field with neutron, photon, electron, two dimensional dose and energy fluence distribution was calculated and there results were compared with measured results. Results : The absorbed dose of fast neutron beams was $6.47\times10^{-3}$ cGy per 1 MU at the 4 cm depth of the water phantom, which is assumed to be effective depth for BNCT. The magnitude of gamma contamination intermingled with fast neutron beams was $65.2{\pm}0.9\%$ at the same depth. In the dose distribution according to the depth of water, the neutron dose decreased linearly and the gamma dose decreased exponentially as the depth was deepened. The factor expressed energy level, $D_{20}/D_{10}$, of the total dose was 0.718. Conclusion : Through the direct measurement using the two ion chambers, which is made different wall materials, and computer calculation of isodose distribution using MCNP simulation method, we have found the dose characteristics of low fluence fast neutron beams. If the power supply and the target material, which generate high voltage and current, will be developed and gamma contamination was reduced by lead or bismuth, we think, it may be possible to accelerator-based BNCT.

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The Role of Primary Radiotherapy for Squamous Cell Carcinoma of the Suprag1ottic Larynx (성문상부 상피세포암에서의 근치적 방사선치료의 역할)

  • Kim, Won-Taek;Kim, Dong-Won;Kwon, Byung-Hyun;Nam, Ji-Ho;Hur, Won-Joo
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.233-243
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    • 2000
  • Purpose : First of all, this study was performed to assess the result of curative radiotherapy and to evaluate different possible prognostic factors for squamous cell carcinoma of the supraglottic larynx treated at the Pusan National University Hospital. The second goal of this study was by comparing our data with those of other study groups, to determine the better treatment policy of supraglottic cancer in future. Methods and Material : Thirty-two patients with squamous cell carcinoma of the supraglottic larynx were treated with radiotherapy at Pusan National University Hospital, from August 1985 to December 1996. Minimum follow-up period was 29 months, Twenty-seven patients (84.4$\%$) were followed up over 5 years. Radiotherapy was delivered with 6 MV photons to the primary laryngeal tumor and regional iymphatics with shrinking field technique. Ail patients received radiotherapy under conventional fractionated schedule (once a day). Median total tumor dose was 70.2 Gy (range, 55.8 to 75.6 Gy) on primary or gross tumor lesion. Thirteen patients had Induction chemotherapy with cisplatln and 5-fluorouracil (1-3 cycles). Patient distribution, according to the different stages, were as follows: stage I, 5/32 (15.6$\%$): stage II, 10/32 (31.3$\%$); stage III, 8/32 (25$\%$): stage IV, 9/32 (28.1$\%$). Results :The 5-year overall survival rate of the whole series (32 patients) was 51.7$\%$. The overall survival rate at 5-years was 80$\%$ in stage I, 66.7$\%$ in stage II, 42.9$\%$ in stage III, 25$\%$ in stage IV (p=0.0958). The S-year local control rates after radiotherapy were as fellows: stage I, 100$\%$; stage II, 60$\%$ stage III, 62.5$\%$; stage IV, 44.4$\%$ (p=0.233). Overall vocal preservation rates was 65.6$\%$, 100% In stage I, 70% in stage II, 62.5$\%$ In stage III, 44.4$\%$ in stage IV (p=0.210). There was no statistical significance in survival and local control rate between neoadjuvant chemotherapy followed by radiotherapy group and radiotherapy alone group. Severe laryngeal edema was found in 2 cases after radiotllerapy, emergent tracheostomy was done. Four patients were died from distant metastsis, . three in lung, one in brain. Double primary tumor was found in 2 cases, one in lung (metachronous), another in thyroid (synchronous). Ulcerative lesions were revealed as unfavorable prognostic factor ( p=0.0215), and radiation dose (more or less than 70.2 Gy) was an important factor on survival (p=0.002). Conclusion : The role of radiotherapy treatment of supraglottic carcinoma is to important factor on survival and to preserve the laryngeal function. Based on our data and other studies, early and moderately advanced supragiottic carcinomas could be successfully treated with either consewative surgery or radiotherapy alone. Both modalities showed similar results in survival and vocal preservation. For the advanced cases, radiotherapy alone is Inadequate for curative aim and surgery combined with radiotherapy should be done in operable patients. When patients refuse operation or want to preserve vocal function, or for the patients with inoperable medical conditions, combined chemoradiotherapy (concurrent) or altered fractionated radiotherapy with or without radiosensitizer should be taken into consideration in future.

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