• Title/Summary/Keyword: 평균와도

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The Spatio-temporal Distribution of Organic Matter on the Surface Sediment and Its Origin in Gamak Bay, Korea (가막만 표층퇴적물중 유기물량의 시.공간적 분포 특성)

  • Noh Il-Hyeon;Yoon Yang-Ho;Kim Dae-Il;Park Jong-Sick
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.9 no.1
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    • pp.1-13
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    • 2006
  • A field survey on the spatio-temporal distribution characteristics and origins of organic matter in surface sediments was carried out monthly at six stations in Gamak Bay, South Korea from April 2000 to March 2002. The range of ignition loss(IL) was $4.6{\sim}11.6%(7.1{\pm}1.6%)$, while chemical oxygen demand(CODs) ranged from $12.25{\sim}99.26mgO_2/g-dry(30.98{\pm}19.09mgO_2/g-dry)$, acid volatile sulfide(AVS) went from no detection(ND)${\sim}10.29mgS/g-dry(1.02{\pm}0.58mgS/g-dry)$, and phaeopigment was $6.84{\sim}116.18{\mu}g/g-dry(23.72{\pm}21.16{\mu}g/g-dry)$. The ranges of particulate organic carbon(POC) and particulate organic nitrogen(PON) were $5.45{\sim}23.24 mgC/g-dty(10.34{\pm}4.40C\;mgC/g-dry)$ and $0.71{\sim}2.99mgN/g-dry(1.37{\pm}0.58mgN/g-dry)$, respectively. Water content was in the range of $43.1{\sim}77.6%(55.8{\pm}5.6%)$, and mud content(silt+clay) was higher than 95% at all stations. The spatial distribution of organic matter in surface sediments was greatly divided between the northwestern, central and eastern areas, southern entrance area from the distribution characteristic of their organic matters. The concentrations of almost all items were greater at the northwestern and southern entrance area than at the other areas in Gamak Bay. In particular, sedimentary pollution was very serious at the northwestern area, because the area had an excessive supply of organic matter due to aquaculture activity and the inflow of sewage from the land. These materials stayed longer because of the topographical characteristics of such as basin and the anoxic conditions in the bottom seawater environment caused by thermocline in the summer. The tendency of temporal change was most prominently in the period of high-water temperatures than low-water ones at the northwestern and southern entrance areas. On the other hand, the central and eastern areas did not show a regular trend for changing the concentrations of each item but mainly showed a higher tendency during the low-water temperatures. This was observed for all but AVS concentrations which were higher during the period of high-water temperature at all stations. Especially, the central and eastern areas showed a large temporal increase of AVS concentration during those periods of high-water temperature where the concentration of CODs was in excess of $20mgO_2/g-dry$. The results show that the organic matters in surface sediments in Gamak Bay actually originated from autochthonous organic matters with eight or less in average C/N ratio including the organic matters generated by the use of ocean, rather than terrigenous organic matters. However, the formation of autochthonous organic matter was mainly derived from detritus than living phytoplankton, indicated the results of the POC/phaeopigment ratio. In addition, the CODs/IL ratio results demonstrate that the detritus was the product of artificial activities such as dregs feeding and fecal pellets of farm organisms caused by aquaculture activities rather than the dynamic of natural ocean activities.

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Effects of Hysteroscopic Septotomy on Pregnancy in Patients with History of Infertility or Recurrent Spontaneous Abortion (불임 또는 습관성 유산 환자에서 중격자궁의 치료가 임신에 미치는 영향)

  • Koo, Hwa-Seon;Cha, Sun-Hwa;Yang, Kwang-Moon;Bae, Ju-Youn;Ahn, Hyun-Suk;Han, Ae-Ra;Park, Chan-Woo;Kang, Inn-Soo;Koong, Mi-Kyoung;Lee, Kyung-Sang
    • Clinical and Experimental Reproductive Medicine
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    • v.37 no.4
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    • pp.361-368
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    • 2010
  • Objective: The aim of this study was to evaluate the influences of uterine septum and their elimination on the reproductive outcomes in women who have history of recurrent spontaneous abortion (RSA) and/or infertility. Methods: The medical records of reproductive outcomes in patients who have had history of RSA and infertility who were diagnosed with uterine septum only by hysterosalpingogram (HSG) between January 2008 and December 2009 were retrospectively analyzed. The subjects who have had severe male factor, tubal factors, other uterine factors, endocrine abnormalities, peritoneal factors, and abnormal karyotyping among both partners were excluded. In 27 patients, confirmation of diagnosis by laparoscopy and elimination of uterine septum by trans-vaginal hysteroscopy was done. Seventeen patients were strongly suspected to uterine septum on HSG but tried to get pregnancy without any other procedure for evaluation and management of uterine anomaly. Age matched 42 patients who have history of RSA and/or infertility and diagnosed to normal HSG finding at same period were randomly selected as control. The medical records of reproductive outcomes were analyzed and compared between groups. Results: The mean time of observation after diagnosis was 21.8 months (10 to 32). 55.6% (15/27) of patients in patients who received trans-vaginal hysteroscopic uterine septotomy were success to get pregnancies and was significantly higher than that of 17 patients who did not receive proper management (23.5%, 4/17, p<0.05). In control population, 40.5% (17/42) were success to pregnancies and the differences were not statistically significant compared to both two study groups. The live birth rate which was excluded pregnancy loss by abnormal fetal karyotyping and congenital anomaly were 75% (9/12) in treated septated uterus group and 84.6% (11/13) in control group each which have no statistically significant different. In patients with septated uterus who did not receive proper management showed lower delivery rate (50%, 2/4) than that of other groups but was not statistically significant. Conclusion: According to present data, women with a uterine septum have an increased chance of successful pregnancy with improved obstetric outcome after proper management of the uterine cavity. And these results were showed in patients with no regard to their reproductive history. But, in case of failed to receive proper management, uterine septum can affect not only pregnancy ongoing but successful pregnancy too.

A Study on the Utilzation of Two Furrow Combine (2조형(條型) Combine의 이용(利用)에 관(關)한 연구(硏究))

  • Lee, Sang Woo;Kim, Soung Rai
    • Korean Journal of Agricultural Science
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    • v.3 no.1
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    • pp.95-104
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    • 1976
  • This study was conducted to test the harvesting operation of two kinds of rice varieties such as Milyang #15 and Tong-il with a imported two furrow Japanese combine and was performed to find out the operational accuracy of it, the adaptability of this machine, and the feasibility of supplying this machine to rural area in Korea. The results obtained in this study are summarized as follows; 1. The harvesting test of the Milyang #15 was carried out 5 times from the optimum harvesting operation was good regardless of its maturity. The field grain loss ratio and the rate of unthreshed paddy were all about 1 percent. 2. The field grain loss of Tong-il harvested was increased from 5.13% to 10.34% along its maturity as shown in Fig 1. In considering this, it was needed that the combine mechanism should be improved mechanically for harvesting of Tong-il rice variety. 3. The rate of unthreshed paddy of Tong-il rice variety of which stem was short was average 1.6 percent, because the sample combine used in this study was developed on basisof the long stem variety in Japan, therefore some ears owing to the uneven stem of Tong-il rice could nat reach the teeth of the threshing drum. 4. The cracking rates of brown rice depending mostly upon the revolution speed of the threshing drum(240-350 rpm) in harvesting of Tong-il and Milyang #15 were all below 1 percent, and there was no significance between two varieties. 5. Since the ears of Tong-il rice variety covered with its leaves, a lots of trashes was produced, especially when threshed in raw materials, and the cleaning and the trashout mechanisms were clogged with those trashes very often, and so these two mechanisms were needed for being improved. 6. The sample combine of which track pressure was $0.19kg/cm^2$ could drive on the soft ground of which sinking was even 25cm as shown in Fig 3. But in considering the reaping height adjustment, 5cm sinking may be afford to drive the combine on the irregular sinking level ground without any readjustment of the resaping height. 7. The harvesting expenses per ha. by the sample combine of which annual coverage area is 4.7 ha. under conditions that the yearly workable days is 40, percentage of days being good for harvesting operation is 60%, field efficiency is 56%, working speed is 0.273m/sec, and daily workable hours is 8 hrs is reasonable to spread this combine to rural area in Korea, comparing to the expenses by the conventional harvesting expenses, if mechanical improvement is supplemented so as to harvest Tong-il rice. 8. In order to harvest Tong-il rice, the two furrow combine should be needed some mechanical improvements that divider can control not to touch ears of paddy, the space between the feeding chain and the thrshing drum is reduced, trash treatment apparatus must be improved, fore and rear adjust-interval is enlarged, and width of track must be enlarged so as to drive on the soft ground.

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Studies on the Cropping system of the Field Crop in Chungnam Area (충남지방(忠南地方)의 전작물(田作物) 작부체계확립(作付體系確立)에 관(關)한 연구(硏究))

  • Choi, Chang Yeol;Kim, Dal Ung;Lee, Jae Chang;Kim, Young Rae
    • Korean Journal of Agricultural Science
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    • v.3 no.1
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    • pp.39-51
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    • 1976
  • As an accempt to increase thc efficiency of land use and the food production to achieve the national goal in the food self-sufficiency, nine cropping systems on the upper-land were examined in pure-stand and in mixtures of soybean, corn, potato and radish. The important conclusions of this study were summarized as follows; 1. The flowering date of soybean was two or three days earlier in pure-stand than in the mixture with corn. The maturing date two days earlier in the pure-stand than in the mixture with corn. The flowering and maturing dates were not different among various cropping systems in corn. 2. The stem length of soybean was significantly different among various cropping systems. Soybean in pure-stand was shorter in stem length than with corn. 3. The number of pods per soybean plant did not give any significant differences among various cultivation methods. 4. The length of internode and the number of nodes per soybean plant in the mixture with corn were greater than in the pure-stand. In the number of branches per plant this was reversed. 5. The average stem dry weight of soybean per 10a was not significantly different among various cultivation methods. 6. The soybean yield per 10a in the pure-stand was obviously greater than the mixture and there were significant differences among cultivation method within the mixture with corn in soybean yield. 7. The 1,000-grain weight of soybean was significantly different and those in the pure-stand was heavier than those in the mixture with corn. 8. Grain weight per soybean plant and the stem diameter in the pure-stand were significantly lesser than those in the mixture with corn. 9. In the comparisons of corn in the pure-stand and in the mixture with soybean, plant height, number of ear per 10a, mean ear weight and remember of grain per plant, 100-grain weight, ear length, ear girth and number of ear pel plant were not significantly different among various cultivation methods except for the grain yield per 10a. 10. In the economic analysis, the mixture with soybean and corn gave the greatest gross income. The combination 7 was the best which was 47.6% increase income comparing with the soybean pure-stand. 11. As it can be assumed, soybean plant was influenced greatly than corn by various cropping system. It is necessary to study more complex cropping system finding and giving more desirable multiple cropping system for the farmer.

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Rural Migration and Changes of Agricultural Population (농민이촌(農民離村)과 농업인구(農業人口)의 변화(變化))

  • Wu, Tsong-Shien;Kim, Kuong-Ho
    • Korean Journal of Agricultural Science
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    • v.1 no.1
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    • pp.91-116
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    • 1974
  • Taiwan agricultural development in the last decade has not been changed much since the accomplishment of land reform program. This is mainly due to the rapid development taken place within industry that agricultural development can not keep pace with. The increasing gap of rural-urban income discrepancy has caused socio-psychological unstability among rural people and inspire wants of out-migration. From 1961 to 1970, population of the ten largest cities showed an annual growth rate of 4.05%, while the population of the remainder of Taiwan showed 2.06%. Assuming the natural increase rate of these two population sections are similar, the difference of rural and urban annual growth rate can be at tributed to the flow of people from rural to urban sectors. The main objective of this paper is to identify the amount of agricultural out-migration and its impact on agricultural development and agricultural extension programs. Specifically, the objectives are to examine (1) rural-urban population composition (2) rural out-migration estimation (3) changes of agricultural population, and (4) implications for agricultural development and extension programs Some of the important findings are listed below; (1) The average agricultural out migration of the period 1960-1969 is estimated at around 60,000 per year. Take Tainan prefecture for example, the Male-Female Migration Ratio is 0.39 for age 20-24, 0.55 for age 25-29, 0.90 for 30-34. It is understood between age 20 and 34, the rural female migration rate is higher than the rural male. (2) Based on the population growth rate of 1950-1969, agricultural population is projected for the period of 1953 to 1989. By 1978, the agricultural population will reach its peak and begin to dedaine from 1980. The projected agricultural population in 1989 is 5,847,566 which occupies 29% of the Taiwan total population. (3) Assuming area of cultivated land keep unchanged as 905,263 ha. in 1970, and tif we can eliminate all 72% of part-time farms, then the average farm acreage for hose full-time farms will be increased to 3.6 hactares. This is unlikely to happen before 1989 without the government interference. (4) Less than 10% of adult farmer s of age 25-64 in 1969 enrolled in Farm Discussion Club, only 5% of adult farm women enrolled in Home Economics Club, and 5% of rural youth enrolled in 4-H Club. These statistics show a fact that only few farmers are reached by extension workers. Based on findings in this paper, some important suggestions are listed for future agricultural development. (1) Improve agricultural structure by decreasing agricultural population (a) Encourage farmers with less than 0.5 ha. of land to seek jobs outside of agriculture (b) Encourage joint cultivation and farm mechanization (c) Discourage rural migrants to Keep farm land (d) Provide occupational guidance program through extension education programs (2) Establish future farmers settlement project to assure rural youth have enough resources for farming. (3) An optimum Population policy should be integrated into rural socio-economic development and national development programs.

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Removal of Red Tide Organisms -2. Flocculation of Red Tide Organisms by Using Loess- (적조생물의 구제 -2. 황토에 의한 적조생물의 응집제거-)

  • KIM Sung-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.455-462
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    • 2000
  • The objective of this study was to examine the physicochemical characteristics of coagulation reaction between loess and red tide organisms (RTO) and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea. The physicochemical characteristics of loess were examined for a particle size distribution, surface characteristics by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrothen closterium and Skeietonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various concentrations of loess, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number. A negative zeta potential of loess increased with increasing pH at $10^(-3)M$ NaCl solution and had -71.3 mV at pH 9.36. Loess had a positive zeta potential of +1,8 mV at pH 1.98, which resulted in a characteristic of material having an amphoteric surface charge. In NaCl and $CaCl_2$, solutions, loess had a decreasing negative zeta potential with increasing $Na^+\;and\;Ca^(+2)$ ion concentration and then didn't result in a charge reversal due to not occurring specific adsorption for $Na^+$ ion while resulted in a charge reversal due to occurring specific adsorption for $Ca^(+2)$ ion. In sea water, loess and RTO showed the similar zeta potential values of -112,1 and -9.2 mV, respectively and sea sand powder showed the highest zeta potential value of -25.7 mV in the clays. EDLs (electrical double-layers) of loess and RTO were extremely compressed due to high concentration of salts included in sea water, As a result, there didn't almost exist EDL repulsive force between loess and RTO approaching each other and then LVDW (London-yan der Waals) attractive force was always larger than EDL repulsive force to easily form a floe. Removal rates of RTO exponentially increased with increasing a loess concentration. The removal rates steeply increased until $800 mg/l$ of loess, and reached $100{\%}$ at 6,400 mg/l of loess. Removal rates of RTO exponentially increased with increasing a G-value. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction. Loess showed the highest RTO removal rates in the clays.

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Studies on the Low Temperature Injury of the Rice Varieties (통일계(統一系) 수도품종(水稻品種)의 저온장해(低溫障害)에 관(關)한 연구(硏究))

  • Choi, Chang-Yoel;Kim, Moon-Kyu;Jo, Jai-Seong;Kim, Choong-Soo
    • Korean Journal of Agricultural Science
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    • v.4 no.1
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    • pp.10-20
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    • 1977
  • An expriment was conducted to determine the rate of germination under low temperature and effects of low temperature on seedling of varieties derived from the cross between Indica and Japonica type of rice. Total of 30 varieties including leading variety, Tongil, were germinated at the temperature of $10^{\circ}C$. and $15^{\circ}C$. to determine the rate of germination, and six varieties also including Tongil were planted in pot, and seedlings were exposed to the temperature of $5^{\circ}C$. and $1^{\circ}C$. for 15 days and damage of plant growth due to low temperature was observed. 1. Under the condition of $10^{\circ}C$., varieties such as Iri #323, Suwon #253, Iri #325, Milyang #22, Suwon #251, and Suwon #267 were showing over 70 percent of germination ratio, while varieties, Dodolokiwase, Milyang #23, Yusin, Iri #328, and Iri #329 were below 10 percent in germination ratio. 2. Under the condition of $15^{\circ}C$., variety Suwon #262 was shown 100 percent of germination and varieties such as Milyg an#22, Dodlokiwase, Tongil, Milyang #29, Suwon #258, Milyang #23, Milyang #24, Milyang #28 and Milyang #21 were over 90 percent in germination ratio. However, varieties such as Iri #328, Iri #329, Jinheung, and Minehikari were below 50 percent in germination rate. 3. Considering the germination rate and average days required to germination, Milyang #22 and Iri #323 were highly resistant varieties to low temperature. The rate of germination of varieties from the cross between Indica and Japonica under low temperature was not always lower than that of varieties from Japonica type of rice. 4. Most of the seedlings of varieties used were quite resistant to $1^{\circ}C$. at least for six hours. However, leaves of rice were exposed to the the temperature of $1^{\circ}C$. for 12 hours, and the withered leaves were recovered soon when put in under normal temperature. The degree of leaf withering under low temperature was lower in Milyang #15, Japonica type than in varietieties belonging to $Indica{\times}Japonica$ type of rice. 5. When the seedlings of varieties such as Josaengtongil, Tongil and Yusin were exposed to the temperature of $1^{\circ}C$. for 36 hours, 70 percent of leaves were withered and when the time of expose were doubled, the leaves were completely died. When the temperature was fluctuated, over 75 percent of leaves were died, while 65 percent of leaves of Milyang #15 were died when exposed to $1^{\circ}C$, for 72 hours. 6. Significant growth retardation was observed for all entries when exposed to $1^{\circ}C$. for 24 to 36 hours. The growth retardation was apparently increased as the time of expose was extended.

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Effect of EGF and IGF-I on in vitro Maturation of Porcine Oocytes and Development of Porcine IVM/IVF Embryos (EGF와 IGF-I의 첨가배양이 돼지 미성숙 난포란의 체외성숙과 배발달에 미치는 영향)

  • Baek, Jun-Jong;Han, Man-Hye;Park, Byung-Kwon;Seo, Kil-Woog;Lee, Kyu-Seung
    • Korean Journal of Agricultural Science
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    • v.34 no.1
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    • pp.19-35
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    • 2007
  • The present study was carried out to examine the effect of EGF and IGF-I in vitro maturation (IVM) of porcine oocytes and development of porcine IVM/IVF embryos. The results were summarized as follows : 1. The rates of nuclear maturation, penetrated oocytes, pronuclear formation, polyspermic oocytes and mean numbers of the penetrated sperm were not different in NCSU-23 maturation medium with 0, 1, 5 and 10 ng/ml EGF and IGF-I (P>0.05). 2. The rates of blastocyst formation at day 7 after in vitro fertilization in 0, 1, 5 and 10 ng/ml EGF groups were $11.2{\pm}1.5%$, $15.0{\pm}8.3%$, $16.8{\pm}2.8%$ and $21.4{\pm}2.0%$, also 0, 1, 5 and 10 ng/ml IGF-I groups were $11.2{\pm}1.5%$, $15.0{\pm}8.3%$, $16.8{\pm}2.8%$ and $21.4{\pm}2.0%$, respectively. In the total cells case, EGF groups were $22.8{\pm}3.7$, $25.7{\pm}5.5$, $26.0{\pm}4.2$ and $35.1{\pm}4.7$, also IGF-I groups were $21.5{\pm}3.7$, $25.2{\pm}2.8$, $26.2{\pm}2.9$ and $33.2{\pm}3.6$, respectively. Both 10 ng/ml EGF group and 10 ng/ml IGF-I group were significantly higher than those of other treatment groups (P<0.05). 3. The rates of blastocyst formation at day 7 in the NCSU23 culture medium of porcine IVF-produced embryos with 0, 1, 5, and 10 ng/ml EGF groups were $14.0{\pm}1.7%$, $16.2{\pm}1.4%$, $16.9{\pm}1.2%$ and $23.1{\pm}1.6%$, also 0, 1, 5, 10 ng/ml IGF-I groups were $13.6{\pm}1.7$, $15.7{\pm}4.5$, $16.0{\pm}0.2$ and $25.0{\pm}0.8$, respectively. And in the total cells case, EGF grups were $21.8{\pm}2.9$, $25.2{\pm}2.8$, $39.7{\pm}2.7$ and $46.2{\pm}3.6$, also IGF-I groups were $20.7{\pm}2.9$, $26.2{\pm}2.9$, $24.6{\pm}2.4$ and $46.1{\pm}3.5$, respectively. Both 10 ng/ml EGF group and 10 ng/ml IGF-I group were significantly higher than those of any other treatment groups (P<0.05). In conclusion, these results suggested that the addition of 10 ng/ml EGF and IGF-I were effective on the blastocyst formation and total cells of blastocysts.

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A Study on the Traumatic Teeth Damage of Children (어린이의 외상성 치아손상에 관한 연구)

  • Yoo, Su-Min;Park, Ho-won
    • Journal of dental hygiene science
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    • v.4 no.1
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    • pp.21-25
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    • 2004
  • In modern times, children's trauma is increasing every year because of car accidents and life environment changes. There is a limit to prevent traumatic damage for oral cavity organization. The fundamental data of trauma treatment and prevention will be presented through the survey and analysis of traumatic teeth damage. I examined 113 patients from Oct. 4th, 2000 to Feb. 27th, 2004 at Dept. of Children's Dental Clinic, Kangnung National University. The results are as follows. (1) The trauma frequency of male subjects is higher than that of female at a rate of 2.05:1. The average age is 5.27 for men and 5.27 for women. The highest percentage of trauma patients is among 2 year old children. It is 21.2%. (2) A patient survey was taken at a trauma treatment hospital. On the first day 34.4% of the patients had come to receive treatment of their first set of teeth. However, after a week, 38.8% of the patients had received treatment on their permanent teeth. (3) As a result of falling, 59% of patients needing treatment on their first set of teeth. 55.1% of patients is permanent teeth. As a result of bump against physical solid, 26.6% of patients is the first set of teeth and 26.5% of patients is permanent teeth. (4) Teeth damage happened at home. 42.1% were male. 35.1% were female. According to trauma, 59.4% of teeth damage happened at home. 28.6% of permanent teeth damage happened at school or kindergarten. (5) According to trauma, the number of teeth damaged was in the first set of teeth are as follows: 56.3%, one-31.3%, three or four-6.3% each. For permanent teeth: two-46.9%, one-28.6%, four over-16.3% and three-8.2%. Over four teeth is larger number for permanent teeth. (6) 56% of first set of teeth patients and 43.4% of permanent teeth patients were male. 56.8% of first set of teeth patients and 43.2% of permanent teeth were female. Trauma happened to both male and female frequently in the first set of teeth. (7) Most of the tooth damage which was in the first set of teeth and permanent teeth was done to the upper jaw. 75% of patients are the first set of teeth. 63.8% of patients are permanent teeth. Trauma is very high in the two mid teeth of the upper jaw. (8) According to trauma survey, 30.2% is from impulse. 28.0% is from crown fracture, 14.7% is from depression. 8.9% is from concussion. 7.1% is from full dislocation of a joint. 2.2% of patients are extrusion. 1.8% is from displacement. According to teeth damage trauma, 35.8% is pulse in the first set of teeth. The breaking of the crown of a tooth happened a lot in permanent teeth. (9) According to data, 43.2% of teeth damage in the first set of teeth goes without treatment. In permanent teeth, it is 38.9%. After treatment, 22.0% of first set of teeth treatment requires a dental pulp treatment. In permanent teeth, which is used for temporary acid etching resin restoration.

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Long-Term Results of 2-Dimensional Radiation Therapy in Patients with Nasopharyngeal Cancer (이차원방사선치료를 시행한 코인두암 환자의 장기 추적 결과 및 예후인자 분석)

  • Lee, Nam-Kwon;Park, Young-Je;Yang, Dae-Sik;Yoon, Won-Sup;Lee, Suk;Kim, Chul-Yong
    • Radiation Oncology Journal
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    • v.28 no.4
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    • pp.193-204
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    • 2010
  • Purpose: To analyze the treatment outcomes, complications, prognostic factors after a long-term follow-up of patients with nasopharyngeal carcinoma treated with radiation therapy (RT) alone or concurrent chemoradiation therapy (CCRT). Materials and Methods: Between December 1981 and December 2006, 190 eligible patients with non-metastatic nasopharyngeal carcinoma were treated at our department with a curative intent. Of these patients, 103 were treated with RT alone and 87 patients received CCRT. The median age was 49 years (range, 8~78 years). The distributions of clinical stage according to the AJCC 6th edition included I: 7 (3.6%), IIA: 8 (4.2%), IIB: 33 (17.4%), III: 82 (43.2%), IVA: 31 (16.3%), IVB: 29 (15.3%). The accumulated radiation doses to the primary tumor ranged from 66.6~87.0 Gy (median, 72 Gy). Treatment outcomes and prognostic factors were retrospectively analyzed. Acute and late toxicities were assessed using the RTOG criteria. Results: A total of 96.8% (184/190) of patients completed the planned treatment. With a mean follow-up of 73 months (range, 2~278 months; median, 52 months), 93 (48.9%) patients had relapses that were local 44 (23.2%), nodal 13 (6.8%), or distant 49 (25.8%). The 5- and 10-year overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) rates were 55.6% and 44.5%, 54.8% and 51.3%, in addition to 65.3% and 57.4%, respectively. Multivariate analyses revealed that CCRT, age, gender, and stage were significant prognostic factors for OS. The CCRT and gender were independent prognostic factors for both DFS and DSS. There was no grade 4 or 5 acute toxicity, but grade 3 mucositis and hematologic toxicity were present in 42 patients (22.1%) and 18 patients (9.5%), respectively. During follow-up, grade 3 hearing loss in 9 patients and trismus in 6 patients were reported. Conclusion: The results of our study were in accordance with findings of previous studies and we confirmed that CCRT, low stage, female gender, and young age were related to improvement in OS. However, there are limitations in the locoregional control that can be achieved by CCRT with 20 conventional radiation therapy. This observation has led to further studies on clarifying the efficacy of concurrent chemotherapy by intensity modulated radiation therapy.