• Title/Summary/Keyword: Research on Research

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The Evaluation of Forest-road Network Considering Optimum Forest-road Arrangement and Yarding Function (최적임도배치(最適林道配置) 및 집재기능(集材機能)을 고려(考慮)한 임도배치망(林道配置網) 평가(評價))

  • Park, Sang Jun;Bae, Sang Tae
    • Current Research on Agriculture and Life Sciences
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    • v.19
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    • pp.45-54
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    • 2001
  • This study was carried out to provide fundamental data for prospective forest-road project and forest-road network arrangement through appraising existing forest-road network with density, extension distance, maximum yarding distance and yarding area, position of forest-road line considered above foundation of two theories, one is "theory of optimal forest-road density" which has expense for yarding cost and constructing forest-road minimized, the other is "theory of optimal forest-road arrangement" which has investment effect maximized. The results are as follows. 1. In density and extension distance of the forest-road by site, it was showed up that density of existing forest-road is lower than that of calculated forest-road. So, it is thought that some additional forest-roads have to be constructed. 2. In the arrangement of the forest-road network by site, it was showed up that the arrangement of calculated forest-road is higher than that of existing forest-road arrangement for the forestry and yarding function. So, it is thought that the arrangement of forest-road network have to be considered to maximize the investment effect. 3. In "mean maximum distance for yarding" and "mean area which yarding can be done" by horizontal and inclined distance, the existing forest-road networks were different from those of calculated forest-road network. So, calculated forest-road network making investment effect maximize is more effective than existing forest-road network. Hence, in prospective forest-road project, it is needed that forest-road network having "area which yarding can be done" maximized through considering function for yarding have to be constructed.

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The effect of four different temperatures on the growth of Aedes albopictus larva (네 가지 다른 온도가 흰줄숲모기(Aedes albopictus) 유충 생장에 미치는 영향)

  • Na, Sumi;Jang, Hyeji;Park, Sojung;Lee, Eunyoung;Doh, Jiseon;Hong, Seungbie;Yi, Hoonbok
    • Journal of Wetlands Research
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    • v.20 no.2
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    • pp.155-160
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    • 2018
  • We investigated to know the growth patterns of Aedes albopictus larva at the four different temperature conditions. Each of 120 individuals was placed into a $20m{\ell}$ vial and 12 sets (a set of 10 vials) were separated into 12 water tanks ($17{\times}24{\times}18cm^3$). Each water tank was composed of 3 the $1^{st}$ instar, 3 the $2^{nd}$ instar, 2 the $3^{rd}$ instar, and 2 the $4^{th}$ instar. Three sets of water tanks were placed under the four different incubator temperatures ($17^{\circ}C$, $21^{\circ}C$, $24^{\circ}C$, $28^{\circ}C$). We found that the eclosion rates were $20.00{\pm}5.77%$ at $21^{\circ}C$ and $3.33{\pm}3.33%$ at other temperatures. For the mosquito larva mortality rate, $1^{st}$ instar was $19.24{\pm}3.65%$, $2^{nd}$ instar was $16.48{\pm}3.25%$, $3^{rd}$ instar was $23.54{\pm}5.06%$, and $4^{th}$ instar was $40.74{\pm}7.08%$. The lowest mortality rate in growth stages according to temperature was $13.33{\pm}6.67%$ at $17^{\circ}C$ in $1^{st}$ instar larva, $7.41{\pm}7.41%$ at $21^{\circ}C$ at $2^{nd}$ instar larva, $10.74{\pm}6.43%$ at $24^{\circ}C$ in $3^{rd}$ instar larva, and $20.37{\pm}5.46%$ at $28^{\circ}C$ in $4^{th}$ instar larva. The survival period of mosquitoes in underwater were $26.33{\pm}0.67days$ at $17^{\circ}C$, $23.33{\pm}1.33days$ at $21^{\circ}C$, $20.00{\pm}2.52days$ at $24^{\circ}C$, and $11.67{\pm}1.20days$ at $28^{\circ}C$. From our results the most effective temperature to the normal growth of mosquito larva was $21^{\circ}C$, and the highest mortality rate was shown at the $4^{th}$ instar stage of larva growth. Our results would provide the basic data for the mosquito larva's growth pattern.

Studies on the N-compounds during Chung-Kook-Jang Meju Fermentation (1) -Changes of Soybean Protein during Chung-Kook-Jang Meju Fermentation- (청국장(淸國醬) 메주 발효과정중(醱酵過程中)의 질소화합물(窒素化合物)의 소장(消長)에 관(關)한 연구(硏究)(I)-대두단백질(大豆蛋白質)의 소장(消長)에 관(關)하여-)

  • Park, Ke-In
    • Applied Biological Chemistry
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    • v.15 no.2
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    • pp.93-109
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    • 1972
  • Three lots of Chung-Kook-Jang were prepared by the use of 2 strains of Bacillus subtilis and Bacillus natto. For four samples taken from each lot in 12 hrs interval changes of nitrogenous compounds, insoluble protein, water soluble protein, peptides, free amino acids, amino and ammonia nitrogens during Chung-Kook-Jang fermentation, were studied together with the changes of moisture, pH, proteolytic enzyme activity. In addition the average peptide length of the peptides of a Bacillus subtilis lot was determined by the method of molecular sieving using ion exchange resin. The results were as follows: 1. The contents of moisture and total-nitrogen changed little in all samples throughout the fermentation as it would be expected. 2. In all three experimental lots the pH became higher gradually from the initial value of 6.65 to the final $7.5{\sim}7.85$ during the fermentation. Proteolytic enzyme activities, in accordance with this pH change, steadily increased up to $48{\sim}60$ hrs. of fermentation and then slightly decreased, probably affected by the high pH. The most strong proteolytic activity was observed in the experimental Chung-Kook-Jang fermentation lot using the Bacillus subtilis K-27 isolated by the author. 3. The contents of insoluble protein nitrogen in soybeans increased markedly (5%) by the cooking, after steeping 12 hrs in water. During the Chung-Kook-Jang fermentation, however, it decreased from 1/2 to 1/10 of that of the cooked soybeans. 4. The contents of water soluble protein nitrogen (5%) whereas, greatly decreased to the value of 1.0% by the cooking; but little changed further during the fermentation, 5. The total contents (0.25%) of peptides, amino, and ammonia-nitrogens, PAA-N., increased almost double by the cooking and steadily became higher as the fermentation proceeded, reaching finally up to$4{\sim}7%$ in 72 hrs fermentation. 6. The amounts of free amino acids of soybean generally decreased during the processing of cooking, even some of them like glutamic acid were destroyed completely, However in the subsequent Chung-Kook-Jang fermentation for 72 hrs., they showed from several to a few hundreds folds increases depending upon the kinds of amino acids. Valine which was contained in HCl-hydrolyzed steeped or cooked soybeans in amounts $220{\sim}267mg%$ was not detected at all as the free amino acid in all fermented samples. 7. Average peptide length (APL) of all fractions, eluted and fractionated by using the Dowex-50 ion exchange resin column, and fraction collector showed the highest value for the cooked soybean and then decreased as the fermentation proceeded. The APL value of effluent showed the highest in 12 hrs fermented sample, The value decreased thereafter by fermentation.

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Suggestion of Learning Objectives in Social Dental Hygiene: Oral Health Administration Area (사회치위생학의 학습목표 제안: 구강보건행정 영역)

  • Park, Su-Kyung;Lee, Ga-Yeong;Jang, Young-Eun;Yoo, Sang-Hee;Kim, Yeun-Ju;Lee, Sue-Hyang;Kim, Han-Nah;Jo, Hye-Won;Kim, Myoung-Hee;Kim, Hee-Kyoung;Ryu, Da-Young;Kim, Min-Ji;Shin, Sun-Jung;Kim, Nam-Hee;Yoon, Mi-Sook
    • Journal of dental hygiene science
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    • v.18 no.2
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    • pp.85-96
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    • 2018
  • The purpose of this study is to propose learning objectives in social dental hygiene by analyzing and reviewing learning objectives in oral health administration area of the existing public oral health. This study is a cross-sectional study. The subjects of the study selected with convenience extraction were 15 members of the social dental hygiene subcommittee of the Korean Society of Dental Hygiene Science. Data collection was conducted by self-filling questionnaire. The research tool is from 48 items of A division in the book of learning objectives in the dental hygienist national examination, and this study classified each of them into 'dental hygiene job relevance', 'dental hygiene competency relevance', 'timeliness', and 'value discrimination of educational goal setting' to comprise 192 items. Also, to collect expert opinions, this study conducted Delphi survey on 7 academic experts. Statistical analysis was performed using the IBM SPSS Statistics ver. 23.0 program (IBM Co., Armonk, NY, USA). Recoding was performed according to the degree of relevance of each learning objective and frequency analysis was performed. This study removed 18 items from the whole learning objectives in the dental hygienist national examination in the oral health administration area of public oral health. Fifteen revisions were made and 15 existing learning objectives were maintained. Forty-five learning objectives were proposed as new social dental hygiene learning objectives. The topics of learning objectives are divided into social security and medical assistance, oral health care system, oral health administration, and oral health policy. As a result of this study, it was necessary to construct the learning objectives of social dental hygiene in response to changing situation at the time. The contents of education should be revised in order of revision of learning objectives, development of competency, development of learning materials, and national examination.

A Study on the ' Zhe Zhong Pai'(折衷派) of the Traditional Medicine of Japan (일본(日本) 의학(醫學)의 '절충파(折衷派)'에 관(關)한 연구(硏究))

  • Park, Hyun-Kuk;Kim, Ki-Wook
    • The Journal of Dong Guk Oriental Medicine
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    • v.10
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    • pp.41-61
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    • 2008
  • The outline and characteristics of the important doctors of the 'Zhe Zhong Pai'(折衷派) are as follows. Part 1. In the late Edo(江戶) period The 'Zhe Zhong Pai', which tried to take the theory and clinical treatment of the 'Hou Shi Pai (後世派)' and the 'Gu Fang Pai(古方派)' and get their strong points to make treatments perfect, appeared. Their point was 'The main part is the art of the ancients, The latter prescriptions are to be used'(以古法爲主, 後世方爲用) and the "Shang Han Lun(傷寒論)" was revered for its treatments but in actual use it was not kept at that. As mentioned above The 'Zhe Zhong Pai' viewed treatments as the base, which was the view of most doctors in the Edo period. However, the reason the 'Zhe Zhong Pai' is not valued as much as the 'Gu Fang Pai' by medical history books in Japan is because the 'Zhe Zhong Pai' does not have the substantiation or uniqueness of the 'Gu Fang Pai', and also because the view of 'gather as well as store up'(兼收並蓄) was the same as the 'Kao Zheng Pai'. Moreover, the 'compromise'(折衷) point of view was from taking in both Chinese and western medical knowledge systems(漢蘭折衷). Generally the pioneer of the 'Zhe Zhong Pai' is seen as Mochizuki Rokumon(望月鹿門) and after that was Fukui Futei(福井楓亭), Wadato Kaku(和田東郭), Yamada Seichin(山田正珍) and Taki Motohiro(多紀元簡). Part 2. The lives of Wada Tokaku(和田東郭), Nakagame Kinkei(中神琴溪), Nei Teng Xi Zhe(內藤希哲), the important doctors of the 'Zhe Zhong Pai', are as follows. First Wada Tokaku(和田東郭, 1743-1803) was born when the 'Hou Shi Pai' was already declining and the 'Gu Fang Pai' was flourishing and learned medicine from a 'Hou Shi Pai' doctor, Hu Tian Xu Shan(戶田旭山) and a 'Gu Fang Pai' doctor, Yoshimasu Todo(吉益東洞). He was not hindered by 'the old ways(古方)' and did not lean towards 'the new ways(後世方)' and formed a way of compromise that 'looked at hardness and softness as the same'(剛柔相摩) by setting 'the cure of the disease' as the base, and said that to cure diseases 'the old way' must be used, but 'the new way' was necessary to supplement its shortcomings. His works include "Dao Shui Suo Yan(導水瑣言)", "Jiao Chiang Fang Yi Je(蕉窗方意解)" and "Yi Xue Sho(醫學說)". Second. Nakagame Kinkei(中神琴溪, 1744-1833) was famous for leaving Yoshimasu Todo(吉益東洞) and changing to the 'Zhe Zhong Pai', and in his early years used qing fen(輕粉) to cure geisha(妓女) of syphilis. His argument was "the "Shang Han Lun" must be revered but needs to be adapted", "Zhong Jing can be made into a follower but I cannot become his follower", "the later medical texts such as "Ru Men Shi Qin(儒門事親)" should only be used for its prescriptions and not its theories". His works include "Shang Han Lun Yue Yan(傷寒論約言)". Third, Nei Teng Xi Zhe(內藤希哲, 1701-1735) learned medicine from Qing Shui Xian Sheng(淸水先生) and went out to Edo. In his book "Yi Jing Jie Huo Lun(醫經解惑論)" he tells of how he went from 'learning'(學) to 'skepticism'(惑) and how skepticism made him learn in 'the six skepticisms'(六惑). In the latter years Xi Zhe(希哲) combines the "Shen Nong Ben Cao Jing(神農本草經)", the main text for herbal medicine, "Ming Tang Jing(明堂經)" of accupuncture, basic theory texts "Huang Dui Nei Jing(皇帝內經)" and "Nan Jing(難經)" with the "Shang Han Za Bing Lun", a book that the 'Gu Fang Pai' saw as opposing to the rest, and became 'an expert of five scriptures'(五經一貫). Part 3. Asada Showhaku(淺田宗伯, 1815-1894) started medicine at Zhong Cun Zhong Zong(中村中倧) and learned 'the old way'(古方) from Yoshimasu Todo and got experience through Ouan Yue(川越) and Fu Jing(福井) and received teachings in texts, history and Wang Yangmin's principles(陽明學) fmm famous teachers. Showhaku(倧伯) meets a medical official of the makufu(幕府), Ben Kang Zong Yuan(本康宗圓), and receives help from the 3 great doctors of the Edo period, Taki Motokato(多紀元堅), Xiao Dao Xue Gu(小島學古) and Xi Duo Cun Kao(喜多村栲窻) and further develops his arts. At 47 he diagnoses the general Jia Mao(家茂) with 'heart failure from beriberi'(脚氣衡心) and becomes a Zheng Shi(徵土), at 51 he cures a minister from France and received a present from Napoleon, at 65 he becomes the court physician and saves Ming Gong(明宮) Jia Ren Qn Wang(嘉仁親王, later the 大正天皇) from bodily convulsions and becomes 'the vassal of merit who saved the national polity(國體)' At the 7th year of the Meiji(明治) he becomes the 2nd owner of Wen Zhi She(溫知社) and takes part in the 'kampo continuation movement'. In his latter years he saw 14000 patients a year, so we can estimate the qualjty and quantity of his clinical skills. Showhaku(宗伯) wrote over 80 books including the "Ju Chuang Shu Ying(橘窻書影)", "Wu Wu Yao Shi Fang Han(勿誤藥室方函)", "Shang Han Biang Shu(傷寒辨術)", "Jing Qi Shen Lun(精氣神論)", "Hunag Guo Ming Yi Chuan(皇國名醫傳)" and the "Xian Jhe Yi Hua(先哲醫話)". Especially in the "Ju Chuang Shu Ying(橘窻書影) he says "the old theories are the main, and the new prescriptions are to be used"(以古法爲主, 後世方爲用), stating the 'Zhe Zhong Pai' way of thinking, In the first volume of "Shang Han Biang Shu(傷寒辨術)" and "Za Bing Lun Shi(雜病論識)", 'Zong Ping'(總評), He discerns the parts that are not Zhang Zhong Jing's writings and emphasizes his theories and practical uses.

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Nutritional Effects of Paper Board Sludge on the Soybean(Glycine max. L.) (대두(大豆)에 대(對)한 제지(製紙) Sludge의 영양학적(營養學的) 연구(昭究))

  • Kim, Moon Kyu;Chang, Ki Woon;Choi, Woo Young;Ham, Suon Kyu;Nam, Yun Kyu;Lee, Chang Jun
    • Korean Journal of Agricultural Science
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    • v.17 no.1
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    • pp.1-8
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    • 1990
  • The paper board sludge(PBS) itself and compost sludge manure(CSM) mixed with sawdust, fowl droppings and urea to the PBS were treated to soybean plants to find the effects of growing characters, yield components, and nutritional compounds in the plant tissues. 1. Percentages of missing plants were 5-9% and 3.6-4.1% in the treatments of PBS and CSM, respectively. After that, the plants were restored to normal conditions. Anyway it is not desirable to use the paper board sludge and immature compost sludge manure in seeding time or to young seedlings. 2. Growth of the plant height was retarded in early growing phase, but it was normal in later stages. And the width and length of the largest leaf, numbers of main stem nodes and pods were not significant among the treatments. 3. The yield intends to increase through the treatments of 1,200, 1,600, and 2,000Kg PBS per 10a. In the CSM treatments with high rate of sawdust, fowl droppings and urea, the numbers of pods and grains were higher than the treatment of high content of PBS. 100-grain and one liter weights were opposite intention. It was suggested that the excess nitrogen amounts from the compost sludge manure than conventional fertilization affected to the yield components. 4. The contents of the main chemical compounds such as N, $P_2O_5$, $K_2O$, Ca, Mg were determined. The concentrations of nitrogen were higher in the treatment of PBS and CSM than none and control. 5. In conclusion, the nutritional effects of PBS were in evidence. To use the sludges, it should be fermented with adequate additives to improve the aeration, C/N ratio, activity of microbial, and other conditions. The sludges could be used to crops as a fertilizers effectively.

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A study on Palpation of the back-shu points (배유혈(背兪穴) 안진(按診)에 관(關)한 고찰(考察))

  • Hong, Mun-Yeup;Park, Won-Hwan
    • The Journal of Dong Guk Oriental Medicine
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    • v.8 no.2
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    • pp.155-173
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    • 2000
  • The diagnosis in Oriental medicine is done by inspection, auscultation and olfaction, interrogation, four diagnostics of pulse feeling and palpation, and various system of identification like identification according to Qi(vital energy), Xue and body fluids, identification according to fair principles, identification according to principles of Wei, Qi, Ying and Xue, identification according to Sanjiao(the triple heater), identification according to four type physical constitution. Sometimes, symptoms and diagnosis techniques according to symptoms is selectively applied for the diagnosis. Among them the pulse feeling and palpation diagnosis technique using the sense of finger and palm of the hand is divided into feeling of pulse and palpation and pressing maneuver. Pressing maneuver is a diagnosis technique pressing and rubbing the affected part in order to attain data of identification including inside and outside condition of the body with regard to the nature, condition and relative seriousness of disease. There are palpation of the skin, palpation the hand and foot, palpation the chest and the abdomen, palpation shu points in pressing maneuver. The diagnosis of the Back Shu points is a technique to examine the change of disease condition from pressure ache, spontaneous ache, tension, relaxation, solidification revealed through channels and collaterals. I investigates starting disease and an attack of disease of twelve pulse and pulse condition through the study relative to the substance and technique of pressing maneuver, and adjusts diagnosis techniques of a region for acupuncture and matters to be attended. The conclusions are as follows. 1. The Shu or stream points in which pathogenic factors go are important to medical treatment of dormant diseases like bowels disease, cold symptom complex and insufficiency symptom complex. 2. Disease classified by system is diagnosed by the condition of process part like pro-trusion, cave-in, tension, relaxation, pressure ache through palpating the Shu or stream points, that is pressing upward or downward left and right sides of the backbone process by hands. 3. In real clinic pressing maneuver of one's back side is very important to patient's diagnosis treatment. Thus, pressing maneuver of one's back side have to be done without omission. 4. Diagnosis must be accomplished through the perception about the diversity of diagnosis technique of bowels disease, the exact knowledge about pressing maneuver of one's back side for enlargement of treatment range and rising of treatment rate, and pressing maneuver of the Shu or the stream points.

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Clinical Outcome after Breast Conserving Surgery and Radiation Therapy for Early Breast Cancer (초기 유방암의 유방 보존수술 후 방사선 치료 결과)

  • Cho, Heung-Lae;Kim, Cheol-Jin;Park, Sung-Kwang;Oh, Min-Kyung;Lee, Jin-Yong;Ahn, Ki-Jung
    • Radiation Oncology Journal
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    • v.26 no.4
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    • pp.204-212
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    • 2008
  • Purpose: This study was performed to evaluate the disease-free survival and risk factors of recurrence in early breast cancer patients who have undergone breast conserving surgery and radiation therapy. Materials and Methods: From March 1997 to December 2002, 77 breast cancer patients who underwent breast conserving surgery and radiation therapy were reviewed retrospectively. The median follow-up time was 58.4 months (range $43.8{\sim}129.4$ months) and the mean subject age was 41 years. The frequency distribution of the different T stages, based on the tumor characteristics was 38 (49.3%) for T1, 28 (36.3%) for T2, 3 for T3, 7 for T is and 1 for an unidentified sized tumor. In addition, 52 patients (67.5%) did not have axillary lymph metastasis, whereas 14 patients (18.1%) had $1{\sim}3$ lymph node metastases and 3 (0.03%) had more than 4 lymph node metastases. The resection margin was negative in 59 patients, close (${\leq}2\;mm$) in 15, and positive in 4. All patients received radiation therapy at the intact breast using tangential fields with a subsequent electron beam boost to the tumor bed at a total dose ranging from 59.4 Gy to 66.4 Gy. Patients with more than four positive axillary lymph nodes received radiation therapy ($41.4{\sim}60.4\;Gy$) at the axillary and supraclavicular area. Chemotherapy was administered in 59 patients and tamoxifen or fareston was administered in 29 patients. Results: The 5 year overall survival and disease-free survival rates were 98.08% and 93.49%, respectively. Of the 77 patients, a total of 4 relapses (5.2%), including 1 isolated supraclavicular relapse, 1 supraclavicular relapse with synchronous multiple distant relapses, and 2 distant relapses were observed. No cases of local breast relapses were observed. Lymph node metastasis or number of metastatic lymph nodes was not found to be statistically related with a relapse (p=0.3289) nor disease-free survival (p=0.1430). Patients with positive margins had a significantly shorter disease-free survival period (p<0.0001) and higher relapse rates (p=0.0507). However, patients with close margins were at equal risk of relapse and disease-free survival as with negative margins (p=1.000). Patients younger than 40 years of age had higher relapse rates (9.3% vs. 0%) and lower disease-free survival periods, but the difference was not statistically significant (p=0.1255). The relapse rates for patients with tumors was 14% for tumor stage T2, compared to 0% for tumor stage T1 tumors (p=0.0284). A univariate analysis found that disease-free survival and relapse rates, T stage, positive resection margin and mutation of p53 were significant factors for clinical outcome. Conclusion: The results of this study have shown that breast conservation surgery and radiation therapy in early breast cancer patients has proven to be a safe treatment modality with a low relapse rate and high disease-free survival rate. The patients with a positive margin, T2 stage, and mutation of p53 are associated with statistically higher relapse rates and lower disease-free survival.

Comparison of Naphthalene Degradation Efficiency and OH Radical Production by the Change of Frequency and Reaction Conditions of Ultrasound (초음파 주파수 및 반응조건 변화에 따른 나프탈렌 분해효율과 OH 라디칼의 발생량 비교)

  • Park, Jong-Sung;Park, So-Young;Oh, Je-Ill;Jeong, Sang-Jo;Lee, Min-Ju;Her, Nam-Guk
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.2
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    • pp.79-89
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    • 2009
  • Naphthalene is a volatile, hydrophobic, and possibly carcinogenic compound that is known to have a severe detrimental effect to aquatic ecosystem. Our research examined the effects of various operating conditions (temperature, pH, initial concentration, and frequency and type of ultrasound) on the sonochemical degradation of naphthalene and OH radical production. The MDL (Method detection limit) determined by LC/FLD (1200 series, Agilient) using C-18 reversed column is measured up to 0.01 ppm. Naphthalene vapor produced from ultrasound irradiation was detected under 0.05 ppm. Comparison of naphthalene sonodegradion efficiency tested under open and closed reactor cover fell within less than 1% of difference. Increasing the reaction temperature from $15^{\circ}C$ to $40^{\circ}C$ resulted in reduction of naphthalene degradation efficiency ($15^{\circ}C$: 95% ${\rightarrow}$ $40^{\circ}C$: 85%), and altering pH from 12 to 3 increased the effect (pH 12: 84% ${\rightarrow}$pH 3: 95.6%). Pseudo first-order constants ($k_1$) of sonodegradation of naphthalene decreased as initial concentration of naphthalene increased (2.5 ppm: $27.3{\times}10^{-3}\;min^{-3}\;{\rightarrow}$ 10 ppm : $19.3{\times}10^{-3}\;min^{-3}$). Degradation efficiency of 2.5 ppm of naphthalene subjected to 28 kHz of ultrasonic irradiation was found to be 1.46 times as much as when exposed under 132 kHz (132 kHz: 56%, 28 kHz: 82.7%). Additionally, its $k_1$ constant was increased by 2.3 times (132 kHz: $2.4{\times}10^{-3}\;min^{-1}$, 28 kHz: $5.0{\times}10^{-3}\;min^{-1}$). $H_2O_2$ concentration measured 10 minutes after the exposure to 132 kHz of ultrasound, when compared with the measurement under frequency of 28 kHz, was 7.2 times as much. The concentration measured after 90 minutes, however, showed the difference of only 10%. (concentration of $H_2O_2$ under 28 kHz being 1.1 times greater than that under 132 kHz.) The $H_2O_2$ concentration resulting from 2.5 ppm naphthalene after 90 minutes of sonication at 24 kHz and 132 kHz were lower by 0.05 and 0.1 ppm, respectively, than the concentration measured from the irradiated M.Q. water (no naphthalene added.) Degradation efficiency of horn type (24 kHz) and bath type (28 kHz) ultrasound was found to be 87% and 82.7%, respectively, and $k_1$ was calculated into $22.8{\times}10^{-3}\;min^{-1}$ and $18.7{\times}10^{-3}\;min^{-1}$ respectively. Using the multi- frequency and mixed type of ultrasound system (28 kHz bath type + 24 kHz horn type) simultaneously resulted in combined efficiency of 88.1%, while $H_2O_2$ concentration increased 3.5 times (28 kHz + 24 kHz: 2.37 ppm, 24 kHz: 0.7 ppm.) Therefore, the multi-frequency and mixed type of ultrasound system procedure might be most effectively used for removing the substances that are easily oxidized by the OH radical.

Comparison of Early Germinating Vigor, Germination Speed and Germination Rate of Varieties in Poa pratensis L., Lolium perenne L. and Festuca arundinacea Schreb. Grown Under Different Growing Conditions (생육환경에 따른 Poa pratensis L., Lolium perenne L. 및 Festuca arundinacea Schreb.의 초종 및 품종별 발아세, 발아속도 및 발아율 비교)

  • 김경남;남상용
    • Asian Journal of Turfgrass Science
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    • v.17 no.1
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    • pp.1-12
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    • 2003
  • Research was Initiated to investigate germination characteristics of cool-season grasses (CSG). Several turfgrasses were tested in different experiments. Experiments I and III were conducted under a room temperature condition of 16$^{\circ}C$ to 23 $^{\circ}C$ and under a constant light condition at 25 $^{\circ}C$, respectively. An alternative environment condition that is a requirement for a CSG germination test by International Seed Testing Association (ISTA) was applied in the Experiment II, consisting of 8-hr light at 25 $^{\circ}C$ and 16-hr dark at 15 $^{\circ}C$. In each experiment, data such as early germinating vigor, germination speed and germination rate were evaluated. Six turfgrass entries were comprised of two varieties each from Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), and tall fescue (TF, Festuca arundinacea Schreb.), respectively. Significant differences were observed in early germinating vigor, germination speed and germination rate. Early germinating vigor as measured by days to 70% seed germination was variable according to environment conditions, turfgrasses and varieties. It was less than 6 days in PR and 6 to 9 days in TF. However, KB resulted in 11 to 13 days under an alternative condition and 11 to 28 days under a room temperature condition. The germination speed was fastest in PR of 7 to 10 days and slowest in KB of 14 to 21 days. However, intermediate speed of 10 to 14 days was associated with TF. There were considerable variations in germination rate among turfgrasses according to different conditions. Generally, PR and TF germinated well, regardless of environment conditions. However, a great difference was observed among KB varieties, when compared with others. Under a room temperature condition, total germination rate was 71.0% in Midnight and 77.7% in Award. And it increased under an alternative condition, which was 81.7% and 91.7% in Award and Midnight, respectively. However, the poorest rate was found under a constant temperature condition, resulting in 18.0% in Award and 15.3% in Midnight. These results suggest that an intensive germination test required by ISTA be needed prior to the decision of seeding rate, including early germinating vigor and germination speed as well as total germination rate. KB is very sensitive to environment conditions and thus its variety selection should be based on a careful expertise.