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Lymph Node Failure Pattern and Treatment Results of Esophageal Cancer Patients Treated with Definitive Radiotherapy (근치목적 방사선치료를 받은 식도암 환자의 림프절 재발양상과 치료성적)

  • Lee, Sun-Young;Kwon, Hyoung-Cheol;Lee, Heui-Hwan;Kim, Jung-Soo;Kim, Soo-Geon
    • Radiation Oncology Journal
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    • v.26 no.2
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    • pp.77-82
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    • 2008
  • Purpose: We evaluated the failure pattern of the celiac axis, gastric lymph node, and treatment outcome in the upper and mid-esophageal region of cancer patients treated by definitive radiotherapy, except when treating the celiac axis and gastric lymph node for treatment volume, retrospectively. Materials and Methods: The study constituted the evaluation 108 patients with locally advanced esophageal cancer receiving radiotherapy or a combination of radiotherapy and chemotherapy at Chonbuk National University Hospital from January 1986 to December 2006. In total, 82 patients treated by planned radiotherapy, except when treating the celiac axis and gastric lymph node for treatment volume, were analysed retrospectively. The study population consisted of 78 men and 2 women(mean age of 63.2 years). In addition, 51 patients received radiotherapy alone, whereas 31 patients received a combination of radiation therapy and chemotherapy. The primary cancer sites were located in the upper portion(17 patients), and mid portion(65 patients), respectively. Further, the patients were in various clinical stages including T1N0-1M0(7 patients), T2N0-1M0(18 patients), T3N0-1M0(44 patients) and T4N0-1M0(13 patients). The mean follow up period was 15 months. Results: The various treatment outcomes included complete response(48 patients), partial response(31 patients) and no response(3 patients). The failure patterns of the lymph node were comprised of the regional lymph node(23 patients) and the distance lymph node which included celiac axis and gastric lymph node(13 patients). However, metastasis was not observed in the regional and distant lymph node in 10 patients, whereas 36 patients were not evaluated. Furthermore, of the 13 patients who developed celiac axis and gastric lymph node metastases, 3 were in stage T1N0-1M0 and 10 were in stage T2-4N0-1M0. A complete response appeared in 12 patients, whereas a partial response appeared in 1 patient. The mean survival time of the patients who appeared for regional and distant lymph node metastasis was 14.4 and 7.0 months, respectively. Conclusion: In locally advanced esophageal cancer patients, who were treated by definitive radiotherapy without celiac axis and gastric lymph node irradiation, the distant lymph node metastasis rate was high and the overall survival rate was lower compared to the regional lymph node metastasis. The incidence of regional and distant lymph node metastasis was high in patients who appeared beyond clinical stage T2 and received radiotherapy alone.

A Comparative Study of the Standard Uptake Values of the PET Reconstruction Methods; Using Contrast Enhanced CT and Non Contrast Enhanced CT (PET/CT 영상에서 조영제를 사용하지 않은 CT와 조영제를 사용한 CT를 이용한 감쇠보정에 따른 표준화섭취계수의 비교)

  • Lee, Seung-Jae;Park, Hoon-Hee;Ahn, Sha-Ron;Oh, Shin-Hyun;NamKoong, Heuk;Lim, Han-Sang;Kim, Jae-Sam;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.3
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    • pp.235-240
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    • 2008
  • Purpose: At the beginning of PET/CT, Computed Tomography was mainly used only for Attenuation Correction (AC), but as the performance of the CT have been increase, it could give improved diagnostic information with Contrast Media. But it was controversial that Contrast Media could affect AC on PET/CT scan. Some submitted thesis' show that Contrast Media could overestimate when it is for AC data processing. On the contrary, the opinion that Contrast Media could be possible to affect the alteration of SUV because of the overestimated AC. But it does not have a definite effect on the diagnosis. Thus, the affection of Contrast Media on AC was investigated in this study. Materials and Methods: Patient inclusion criteria required a history of a malignancy and performance of an integrated PET/CT scan and contrast- enhanced CT scan within a 1-day period. Thirty oncologic patients who had PET/CT scan from December 2007 to June 2008 underwent staging evaluation and met these criteria. All patients fasted for at least 6 hr before the IV injection of approximately 5.6 MBq/kg (0.15 mCi/kg) of $^{18}F$-FDG and were scanned about 60 min after injection. All patients had a whole body PET/CT performed without IV contrast media followed by a contrast-enhanced CT on the Discovery STe PET/CT scanner. CT data were used for AC and PET images came out after AC. The ROIs drew and measured SUV. A paired t-test of these results was performed to assess the significance of the difference between the SUV obtained from the two attenuation corrected PET images. Results: The mean and maximum Standardized Uptake Values (SUV) for different regions averaged over all Patients. Comparing before using Contrast Media and after using, Most of ROIs have the increased SUV when it did Contrast Enhanced CT compare to Non-Contrast enhanced CT. All regions have increased SUV and also their p value was under 0.05 except the mean SUV of the Heart region. Conclusion: In this regard, the effect on SUV measurements that occurs when a contrast-enhanced CT is used for attenuation correction could have significant clinical ramifications. But some submitted thesis insisted that the percentage change in SUV that can determine or modify clinical management of oncology patients is small. Because there was not much difference that could be discovered by interpreter. But obviously the numerical change was occurred and on the stage finding primary region, small change would be base line, such as the region of liver which has greater change than the other regions needs more attention.

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Effects of Applying Cattle Slurry and Mixed Sowing with Legumes on Productivity, Feed Values and Organic Stock Carrying Capacity of Winter Forage Crops in Gyeongbuk Regions (경북지역에서 액상우분뇨 시용과 콩과작물의 혼파가 동계사료작물의 생산성, 사료가치 및 단위면적당 유기가축 사육능력에 미치는 영향)

  • Hwangbo, Soon;Jo, IK-Hwan
    • Korean Journal of Organic Agriculture
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    • v.21 no.3
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    • pp.451-465
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    • 2013
  • This study was conducted to estimate Hanwoo carrying capacity when whole crop barley, rye, wheat and tritcale as winter forage crops was grown on different applying sources (chemical fertilizer, cattle or organic fertilizer) and mixed sowing combination with hairy vetch or forage pea during the period of 2011~2012. The experimental plots within whole crop barley or rye were consisted of 7 treatments, which were non-fertilizer, chemical fertilizer (P+K), chemical fertilizer (N+P+K), organic fertilizer, cattle slurry, cattle slurry with hairy vetch, and cattle slurry with forage pea. Each plot was triplicates and experimental treatments were allocated in the randomized complete block design. For whole crop barley, annual mean dry matter (DM) and total digestible nutrients (TDN) yields were the highest in N+P+K plots, but there were no significant differences among organic fertilizer, cattle slurry and mixed sowing with legumes. The TDN were the highest in mixed sowing plots of forage pea plus cattle slurry application. As 450 kg Hanwoo heifers were fed diets included 70% whole crop barley, organic fertilizer, cattle slurry application and mixed sowing plots of forage pea is capable of raising average 2.8 to 3.1 heads/ha a year. For whole crop rye, annual mean DM were the highest in N+P+K plots, but there were no significant differences among cattle slurry. Organic fertilizer application significantly increased TDN and relative feed value (RFV) in comparison with treatments of N+P+K fertilization as chemical fertilizers. In case of 450 kg Hanwoo heifers fed diets included 70% forage rye, it is estimated that cattle slurry application (mixed sowing with legumes) plots can rear average 2.8~ 3.2 heads/ha a year. For whole crop wheat, annual DM, crude protein, and TDN yields of application groups and mixed sowing treatment with legumes showed 6.90~7.44, 0.53~0.60 and 4.35~5.04 ton/ha, respectively. In case of 450 kg Hanwoo heifers fed diets included 70% forage rye, it is estimated that cattle slurry application (mixed sowing with legumes) plots can rear average 3.1~3.7 heads/ha a year. For Triticale, TDN yield was significantly (P<0.05) higher N+P+K plots, organic ferilizer, cattle slurry, cattle slurry with legumes than for no fertilizer and N+P+K plots. The Crude protein (CP) contents were the highest in mixed sowing plots of forage pea plus cattle slurry application. In case of 450 kg Hanwoo heifers fed diets included 70% forage triticale, it is estimated that cattle slurry application (mixed sowing with legumes) plots can rear average 3.4~3.7 heads/ha a year. It can be concluded that, on the basis of DM yield, not only mixed sowing with legumes by applying cattle slurry rather than single sowing of whole crop barley or whole crop rye enhanced production yield and feed values, but also it could be a substitute for imported grains as dietary protein sources in the case of feeding Hanwoo.

Regional Development And Dam Construction in Korea (한국의 지역개발과 댐건설)

  • 안경모
    • Water for future
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    • v.9 no.1
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    • pp.38-42
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    • 1976
  • Because of differences in thoughts and ideology, our country, Korea has been deprived of national unity for some thirty years of time and tide. To achieve peaceful unification, the cultivation of national strength is of paramount importance. This national strength is also essential if Korea is to take rightful place in the international societies and to have the confidence of these societies. However, national strength can never be achieved in a short time. The fundamental elements in economic development that are directly conducive to the cultivation of national strength can be said to lie in -a stable political system, -exertion of powerful leadership, -cultivation of a spirit of diligence, self-help and cooperation, -modernization of human brain power, and -establishment of a scientific and well planned economic policy and strong enforcement of this policy. Our country, Korea, has attained brilliant economic development in the past 15 years under the strong leadership of president Park Chung Hee. However, there are still many problems to be solved. A few of them are: -housing and home problems, -increasing demand for employment, -increasing demand for staple food and -the need to improve international balance of payment. Solution of the above mentioned problems requires step by step scientific development of each sector and region of our contry. As a spearhead project in regional development, the Saemaul Campaign or new village movement can be cited. The campaign is now spreading throughout the country like a grass fire. However, such campaigns need considerable encouragement and support and the means for the desired development must be provided if the regional and sectoral development program is to sucdceed. The construction of large multipurpose dams in major river basin plays significant role in all aspects of national, regional and sectoral development. It ensures that the water resource, for which there is no substitute, is retained and utilized for irrigation of agricultural areas, production of power for industry, provision of water for domestic and industrial uses and control of river water. Water is the very essence of life and we must conserve and utilize what we have for the betterment of our peoples and their heir. The regional and social impact of construction of a large dam is enormous. It is intended to, and does, dras tically improve the "without-project" socio-economic conditions. A good example of this is the Soyanggang multipurpose dam. This project will significantly contribute to our national strength by utilizing the stored water for the benefit of human life and relief of flood and drought damages. Annual average precipitation in Korea is 1160mm, a comparatively abundant amount. The catchment areas of the Han River, Keum River, and Youngsan River are $62,755\textrm{km}^2$, accounting for 64% of the national total. Approximately 62% of the national population inhabits in this area, and 67% of the national gross product comes from the area. The annual population growth rate of the country is currently estimated at 1.7%, and every year the population growth in urban area increases at a rising rate. The population of Seoul, Pusan, and Taegu, the three major cities in Korea, is equal to one third of our national total. According to the census conducted on October 1, 1975, the population in the urban areas has increased by 384,000, whereas that in rural areas has decreased by 59,000,000 in the past five years. The composition of population between urban and rural areas varied from 41%~59% in 1959 to 48%~52% in 1975. To mitigate this treand towards concentration of population in urban areas, employment opportunities must be provided in regional and rural areas. However, heavy and chemical industries, which mitigate production and employment problems at the same time, must have abundant water and energy. Also increase in staple food production cannot be attained without water. At this point in time, when water demand is rapidly growing, it is essential for the country to provide as much a reservoir capacity as possible to capture the monsoon rainfall, which concentarated in the rainy seaon from June to Septesmber, and conserve the water for year round use. The floods, which at one time we called "the devil" have now become a source of immense benefit to Korea. Let me explain the topographic condition in Korea. In northern and eastern areas we have high mountains and rugged country. Our rivers originate in these mountains and flow in a general southerly or westerly direction throught ancient plains. These plains were formed by progressive deposition of sediments from the mountains and provide our country with large areas of fertile land, emminently suited to settlement and irrigated agricultural development. It is, therefore, quite natural that these areas should become the polar point for our regional development program. Hower, we are fortunate in that we have an additional area or areas, which can be used for agricultural production and settlement of our peoples, particularly those peoples who may be displaced by the formation of our reservoirs. I am speaking of the tidelands along the western and southern coasts. The other day the Ministry of Agriculture and Fishery informed the public of a tideland reclamation of which 400,000 hectares will be used for growing rice as part of our national food self-sufficiency programme. Now, again, we arrive at the need for water, as without it we cannot realize this ambitious programme. And again we need those dams to provide it. As I mentioned before, dams not only provide us with essential water for agriculture, domestic and industrial use, but provide us with electrical energy, as it is generally extremely economical to use the water being release for the former purposes to drive turbines and generators. At the present time we have 13 hydro-electric power plants with an installed capacity of 711,000 kilowatts equal to 16% of our national total. There are about 110 potential dams ites in the country, which could yield about 2,300,000 kilowatts of hydro-electric power. There are about 54 sites suitable for pumped storage which could produce a further 38,600,000 kilowatts of power. All available if we carefully develop our water resources. To summarize, water resource development is essential to the regional development program and the welfare of our people, it must proceed hand-in-hand with other aspects of regional development such as land impovement, high way extension, development of our forests, erosion control, and develop ment of heavy and chemical industries. Through the successful implementation of such an integrated regional development program, we can look forward to a period of national strength, and due recognition of our country by the worlds societies.

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Off-pump Coronary Artery Bypass Surgery Versus Drug Eluting Stent for Multi-vessel Coronary Artery Disease (다혈관 관상동맥질환에서의 심폐바이패스를 사용하지 않은 관상동맥우회술과 약물용출 스텐트시술)

  • Lee, Jae-Hang;Kim, Ki-Bong;Cho, Kwang-Ree;Park, Jin-Shik;Kang, Hyun-Jae;Koo, Bon-Kwon;Kim, Hyo-Soo;Sohn, Dae-Won;Oh, Byung-Hee;Park, Young-Bae
    • Journal of Chest Surgery
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    • v.41 no.2
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    • pp.202-209
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    • 2008
  • Background: The introduction of Drug Eluting Stents (DES) decreased the number of patients referred for coronary artery bypass grafting (CABG). The impact of DES on CABG (Step 1) was studied and compared with the 1-year outcome after CABG with DES (Step 2). Material and Method: Surgical results for patients who underwent off-pump CABG (OPCAB) before the introduction of DES(n=298) were compared with those who underwent OPCAB after the introduction of DES (n=288) (Step 1). Postoperative 30-day and 1-year results were also compared between the patients who underwent percutaneous coronary intervention (PCI) using DES (n=220) and those who underwent OPCAB (n=255) (Step 2). Result: Since the introduction of DES, the ratio of CABG versus PCI decreased. In the CABG group, the number of high risk patients such as elderly patients (age 62 vs. 64, p=0.023), those with chronic renal failure (4% vs. 9%, p=0.021), calcification of the ascending aorta (9% vs. 15%, p=0.043), or frequency of urgent or emergent operations (12% vs. 22%, p=0.002) increased. However, there were no differences in the cardiac death and graft patency rates between the two groups (step 1). During the one-year follow up period, the rate of target vessel revascularization (12.3% vs. 2.4%, p<0.001) and major adverse cardiac events (MACE: death, myocardial infarct, TVR) were higher in the DES than the CABG group (13.6% vs 4.3%) (stage 2). Conclusion: Introduction of DES decreased the number of patients referred for surgery, and increased the comorbidity in patients who underwent CABG. DES increased the rate of target vessel revascularization, and the occurrence of MACE during the 1-year follow-up. However, there was no difference in the incidence of myocardial infarction and cardiac death between the two groups.

A Study on Determination of Consumptive Use Needed in the Vegetable Plots for the Prevention of Drought Damage (고등채소의 한해를 방지하기 위한 포장 용수량 결정에 관한연구)

  • 최예환
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.15 no.2
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    • pp.2949-2967
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    • 1973
  • The purpose of this study is to find out and determine the minimum consumptive use of water for Korean cabbage and turmp, so that the minimum water requirement can be secured always for a stable cultivation of these vegetables regardless of weather conditions. The experiment was conducted in two periods; first one from May to July and second one from August to October, each experiment with two varieties of cabbage and two varieties of radish with 2 replicants and 15 treatments. The results found from the above are briefly as follows: 1. Since the mean soil moisture equivalent 64 days after the treatment was 28.5% and the soil moisture content at the time was 2.67% which is far less than that of the wilting point, the crop seemed to be extremely caused by a drought. 2. The rate of 51 days after the seeding, soil moisture content of plot No.2 where irrigation has been continuous was the highest or 21.3%, whereas the plot No.14 without irrigations was 11.2% and the lowest. Therefore, the soil moisture content for the minimum qrowth seemed to be 20%. 3. The consumptive coefficient of Blaney and Criddle on cabbage in two periods were K=1.14 and 0.97 respectively, and on radish in two periods were K=1.06 and 0.86 respectively, thus, cabbage was higher than radish. The consumptive coefficient in the first experiment (May-July) was 0.17 to 0.20 higher than the 2nd experiment(August-October). 4. Nomally, cabbage and radish germinate within one week, however, the germination ot these crops which were treated with a suspended water supply from the beginning took two full weeks. 5. When it elapsed 30 days after seeding, the conditions in plot 1,2 and 3 were fairly good however, the crops in the plops other than these showed a withering and the leaves were withered and changed into high green due to an extrem drought. Though it was about same at the beginning, the drought damage on cabbage was worse than that on radish period, and the reasos for this appears in the latter that the roots are grown too deep. 6. The cabbage showed a high affinity between treated plots and varieties. Consequently, it can be said that cabbage is very suseptive to drought damage, and the yield showed a difference of 35% to 56% depending on the selection oe varieties. 7. The radish also showed a high affinity between the treated plots, however, almost us affinity existed between varieties. Therfore, the yield of radish largely depends on the extent of drought, and the selection of variety does not affect at all. 8. The normal consumptive use on cabbage is $0.62{\ell}/sec$, while that on radish is $0.64{\ell}/sec$, and the minimum optimum water requirement that was obtained in this study is $4,000cc/day/m^3$ or $0.462{\ell}/sec/ha$.

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Studies on the Effect of Low Temperature Treatment at Meiotic, Heading and Seedling Stage in Paddy Rice (수도의 장해형 냉해에 관한 연구)

  • Hong-Suk Lee;Hyung-Yull Cho;Pyeong-Ki Yim;Hoon Heu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.15
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    • pp.85-97
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    • 1974
  • In order to clarify the inducing conditions and cause of sterility in rice plants, 4 varieties were cooled at 3 different levels of temperature combined with 3 different levels of treatment period. And 19 varieties were tested to examine the varietal difference of cold resistance. The results obtained were summarized as follows; 1. There were significant varietal differences in the effect of cooling treatment at meiotic stage. Suwon 213-1 was induced heavy sterility by 3 day cooling treatment at 17.5$^{\circ}C$ whereas Hayayuki, Nongpaik and Jinheung were induced a little sterility by 3 day cooling treatment at 15$^{\circ}C$ and 5 day treatment at 17.5$^{\circ}C$. The per cent of grain fertility was correlated significantly with the delayed days to heading, the degree of panicle extraction (Suwon 213-1, Nongpaik, Jinheung), culm length (Nongpaik, Suwon 213-1), and Auricle distance (Suwon 213-1). The degree of sterility was able to be estimated from the linear regression equation between the degree of panicle extraction (distance from panicle neck to flag leaf) and fertility percentage. In the case of heavy cold damage by the treatment of low temperature at meiotic stage, the rice plant had somewhat lower pollen density per anther, small and ununiform anther and pollen in size, and more sterile pollen grains. Suwon 213-1 showed anthesis in almost all spikelets, while Nongpaik, Jinheung and Hayayuki indicated considerable number of indehisced anther at 5 days after heading. 2. The fertility were not generally higher in cooling treatment at heading stage than at meiotic stage treatment. And significant correlation was found between the percentage of grain fertility treated at above two stages. Nongpaik and Jinheung were not affected in percentage of fertility by 5 day treatment at 15$^{\circ}C$ when these were treated at heading stage. Indehisced anthers were not found in Suwon 213-1 and Hayayuki, but Nongpaik and Jinheung showed more anthers which did not show anthesis 3. There was different varietal response to low temperature which was indicated by the decrease of grain fertility resulted from cooling treatment at meiotic stage. Jaekeun and Jinheung did not show low fertility but Milseong, Suwon 210, Satominoli and Suwon 213-1 showed outstanding decrease in fertility percentage by the cooling treatment at meiotic stage. The varieties which had low fertility were likely to have low pollen density per anther, abnormal anthers, small size po]]en grains and many sterile pollens. 4. Remarkable varietal difference of cold resistance was found in heading stage cooling treatment. Nongpaik, Jinheung, Jaekeun, Paltal, Akibare, Milseung and Palkeong were not affected in grain fertility by cooling treatments but Nonglimna No. 1, Suseong, Hayayuki, Suwon 213-1 and Suwon 210 showed significantly high sterility as treated by cool temperature. Most of the varieties showed higher fertility by cooling treatment at heading stage than meiotic stage but Hayayuki, Suseong and Nonglimna No.1 showed lower fertility when these were treated at heading stage than meiotic stage. There were two grops of varieties in the response to cooling treatment, one was somewhat non-anthesised and the other showed full anthesis. 5. In cold injury test of young seedlings, the result of observation was not accorded with the degree of growth inhibition. As a general, Palkeum and Suseong were highly torelant to cool temperature but Suwon 213-1, Jaekeun, Paltal, Shirogane, Palkeong, Mankyung were highly susceptible. 6. There is no significant correlation between the degree of young seedling cold damage and or the degree of growth retardation at seedling stage and grain fertility resulted from coding treatment both heading and meiotic stage.

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Hematological Characteristic of Bastard halibut according to Cultured experiment of Mari-floating netcage-II On the Blood serum constituents and Electrolytes in blood serum (넙치의 해상(海上)가두리 사육시험(飼育試驗)에 따른 혈액학적(血液學的) 연구(硏究)-II 혈청화학지수(血淸化學指數) 및 전해질지수(電解質指數)에 대(對)하여)

  • Sim, Doo-Saing;Jeon, Im-Gi;Min, Kwang-Sik;Lee, Jong-Moon
    • Journal of fish pathology
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    • v.3 no.1
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    • pp.39-50
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    • 1990
  • Chemical constituents in blood serum and electrolytes were mearsured to the cultured flounder, Paralichthys olivaceus classified by control group and establishments of mari-netcages from April 7, 1990 to May 8, 1990. The total protein, albumin and glucose were $5.74{\pm}0.83g/dl$, $0.94{\pm}0.22g/dl$ and $62{\pm}29mg/dl$, respectively in the blood serum constituents of control group. The potassium, sodium and calcium were $2.5{\pm}1.1\;mmol/l$, $169{\pm}17\;mmol/l$ and $5.0{\pm}1.7\;mg/l$, respectively in the electrolytes of control group. In the variation of chemical constituents and electrolytes in blood serum, glucose of PVC group was alone represented $66{\pm}19\;mg/dl$ as control level on the 9th after locomotion to mari-floating netcages, and was stable within period of experiment in comparision with the other group. Subsequently stable netron group was decreased $49{\pm}15\;mg/dl$ on the 12th. Total protein of netron group was alone represented $5.72{\pm}1.11\;g/dl$ as control level on the 27th. Albumin of PVC group was stable, and was retruned $1.00{\pm}0.18\;g/dl$ as control level on the 27th. Potassium of PVC and netron group were stable within priod of experiment. Sodium of PVC, pole-PVC group were stable, and were $169{\pm}17{\sim}178{\pm}10\;mmol/l$, $173{\pm}10{\sim}179{\pm}9\;mmol/l$ respectively in blood serum with in priod of experiment. According to the combined results of chemical constituents in blood serum and electrolytes classified by establishment of mari-floating netcages, the experiment group that were stabilized variation were in order of PVC, netron and pole-PVC group. But the other groups were extended the range of variation.

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The Study of Water Environment Variations in Lake Hwajinpo (화진포호의 수환경변화에 관한 연구)

  • Heo, Woo-Myung;Choi, Sang-Gyu;Kwak, Sung-Jin;Bhattrai, Bal Dev;Lee, Eun-Joo
    • Korean Journal of Ecology and Environment
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    • v.44 no.1
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    • pp.9-21
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    • 2011
  • This study is conducted to know the change in water environment of Lake Hwajinpo from 2000 to 2008 with physico-chemical parameters; salinity, dissolved oxygen, total phosphorus and total nitrogen and others. And zooplanktons and phytoplanktons were studied from 2007 to 2008. From the water quality data of Lake Hwajinpo from 2000 to 200S; water temperature, salinity, transparency, chemical oxygen demand and dissolved oxygen ranges are $2.8{\sim}29.4^{\circ}C$, 0.23~33.2‰, $0.2{\sim}1.8\;m$, $0.2{\sim}20.2\;mg\;L^{-1}$ and $0.1{\sim}17.4\;mg\;L^{-1}$ and the average values are $18.0^{\circ}C$, 15.7‰, 0.7 m, $5.7\;mg\;L^{-1}$ and $8.0\;mg\;L^{-1}$, respectively. Total phosphorus (TP) and total nitrogen (TN) ranges are $0.024{\sim}0.869\;mg\;L^{-1}$ (average 0.091) and $0.240{\sim}5.310\;mg\;L^{-1}$ (average 1.235). Average TN/TP ratio is 16.4. The annual variations in COD, TP, TN and Chl.${\alpha}$ are compared. COD in 2000 is $4.83\;mg\;L^{-1}$ and 2008 is $1.80\;mg\;L^{-1}$ which is reduced by $0.34\;mg\;L^{-1}$ every year. TP in 2000 is $0.07\;mg\;L^{-1}$ and 2008 is $0.05\;mg\;L^{-1}$ reduced gradually. Yearly reduction in TN is $0.09\;mg\;L^{-1}$, in 2000 and 2008 the values are $1.54\;mg\;L^{-1}$ and $0.77\;mg\;L^{-1}$ respectivly. Chl.${\alpha}$ in 2000 is $46.30\;{\mu}g\;L^{-1}$ and $5.78\;{\mu}g\;L^{-1}$ in 2008; yearly reduction is $4.50\;{\mu}g\;L^{-1}$. The tropic state index (TSI) in south and north parts of Lake Hwajinpo in 2000 are 67 and 63 which are reduced to 63 and 59 in 2008 respectively. North and south part of Lake Hwajinpo have 67 species of phytoplankton under 47 families in 2007 and 2008. Dominant species in south part in 2007 are; Asterococcus superbus in May, Lyngbya sp. in September and Trachelomonas spp. in November and in 2008 Anabaena spiroides in August are abundant and varies with time. Zooplankton species in Lake Hwajinpo are 25 of 25 families. Dominant species in south part in May and August 2007 and May and November in 2008 Copepoda larvae and in September 2007 Protozoa spp. of Protozoan and Brachionus plicatilis and Brachionus urceolaris of Cladocera in August 2008. Dominant species in north part Asplanchna sp. of Cladecera in August and November 2007 and rest of the time are larvae of Copepoda. In this way, the water quality of Lake Hwajinpo is changing with slow rate in the long period specially nutrients concentration (TP, TN etc) is decreasing.

Spatio-temporal Fluctuations with Influences of Inflowing Tributary Streams on Water Quality in Daecheong Reservoir (대청호의 시공간적 수질 변화 특성 및 호수내 유입지천의 영향)

  • Kim, Gyung-Hyun;Lee, Jae-Hoon;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.45 no.2
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    • pp.158-173
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    • 2012
  • The objectives of this study were to analyze the longitudinal gradient and temporal variations of water quality in Daecheong Reservoir in relation to the major inflowing streams from the watershed, during 2001~2010. For the study, we selected 7 main-stream sites of the reservoir along the main axis of the reservoir, from the headwater to the dam and 8 tributary streams. In-reservoir nutrients of TN and TP showed longitudinal declines from the headwater to the dam, which results in a distinct zonation of the riverine ($R_z$, M1~M3), transition ($T_z$, M4~M6), and lacustrine zone ($L_z$, M7) in water quality, as shown in other foreign reservoirs. Chlorophyll-a (CHL) and BOD as an indicator of organic matter, were maximum in the $T_z$. Concentration of total phosphorus (TP) was the highest (8.52 $mg\;L^{-1}$) on March in the $R_z$, and was the highest (165 ${\mu}g\;L^{-1}$) in the $L_z$ on July. Values of TN was the maximum (377 ${\mu}g\;L^{-1}$) on August in the $R_z$, and was the highest (3.76 $mg\;L^{-1}$) in the $L_z$ on August. Ionic dilution was evident during September~October, after the monsoon rain. The mean ratios of TN : TP, as an indicator of limiting factor, were 88, which indicates that nitrogen is a surplus for phytoplankton growth in this system. Nutrient analysis of inflowing streams showed that major nutrient sources were headwater streams of T1~T2 and Ockcheon-Stream of T5, and the most influential inflowing stream to the reservoir was T5, which is located in the mid-reservoir, and is directly influenced by the waste-water treatment plants. The key parameters, influenced by the monsoon rain, were TP and suspended solids (SS). Empirical models of trophic variables indicated that variations of CHL in the $R_z$ ($R^2$=0.044, p=0.264) and $T_z$ ($R^2$=0.126, p=0.054) were not accounted by TN, but were significant (p=0.032) in the $L_z$. The variation of the log-transformed $I_r$-CHL was not accounted ($R^2$=0.258, p=0.110) by $I_w$-TN of inflowing streams, but was determined ($R^2$=0.567, p=0.005) by $I_w$-TP of inflowing streams. In other words, TP inputs from the inflowing streams were the major determinants on the in-reservoir phytoplankton growth. Regression analysis of TN : TP suggested that the ratio was determined by P, rather than N. Overall, our data suggest that TP and suspended solids, during the summer flood period, should be reduced from the eutrophication control and P-input from Ockcheon-Stream should be controlled for water quality improvement.