• Title/Summary/Keyword: 자연연구

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Characteristics of Temperature, Humidity and PPF Distribution by Covering Method and Environmental Control in Double Covering Greenhouse (이중피복 온실의 피복방법과 환경조절에 따른 온습도 및 광합성유효광량자속 분포 특성)

  • Lee, Hyun-Woo;Sim, Sang-Youn;Kim, Young-Shik
    • Journal of Bio-Environment Control
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    • v.21 no.1
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    • pp.1-11
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    • 2012
  • The objective of the present study is to provide data needed to find double covering method to be able to improve environment of temperature, humidity and PPF in tomato greenhouse. The distribution charts of temperature, humidity and PPF which were measured in environment control conditions such as thermal insulation, air heating, roof ventilation and air fog cooling in conventional and air inflated double layers greenhouses were drawn and analysed. The thermal insulation effect of the air inflated greenhouse was the same as that of conventional greenhouse because the temperature between insulation curtain and roof covering material was equal in heating season. The ventilation effect of the air inflated greenhouse was superior to the conventional greenhouse. The temperature distribution in the fog cooled greenhouse was uniform and the cooling effect was about $3.5^{\circ}C$. The condensation on the roof covering surface could be controlled by removing the moisture between insulation curtain and roof covering by using humidifier. The PPF of conventional greenhouse was more decreased than the air inflated greenhouse as time went by because the transmittance of conventional greenhouse declined by dust collected on the inside plastic film owing to rolling up and down operation for ventilation.

Toxicity and Carcinogenicity of the Fusarium moniliforme MRC 826 Culture Material in Rats (랫드에서 Fusarium moniliforme MRC 826 배양물질의 독성 및 발암성에 관한 연구)

  • 신동진;신광순;이영순
    • Journal of Food Hygiene and Safety
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    • v.8 no.1
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    • pp.37-53
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    • 1993
  • F. moniliforme MRC 826, a common fungal contaminant of com, has been known to produce a group of mycotoxins, the fumonisins. By thin layer chromatography, fumonisin $B_{1}$ was detected in the F. moniliforme MRC 826 com culture material(CM) extracts. This study was performed to compare the toxicity and carcinogenicity of F. moniliforme MRC 826 CM with those of aflatoxin $B_1(AFB_1)$ in rats. The toxicity was tested over a period of 7 days in ten female Sprague-Dawley (SD) rats. Treatment group were fed a 1 : 1 mixture(wt/wt) of ground CM and basal diet in powder form, while other negative control group were given basal diet alone. The principal pathological changes in rats treated with 50% CM were hepatocellular hydropic degeneration and renal tubular necrosis. The cancer-promoting activity of CM was evaluated in the rat liver diethylnitrosamine-two thirds partial hepatectomy(DEN-PH) model for carcinogenesis. 70 male SO rats(ca. 170 g) were randomized into 5 groups. Group I served as the positive controls and received the basal diet containing 2 ppm $AFB_{1}$ group 2 received 5% CM, group 3 received 2.5% CM, group 4 received 5% normal com and group 5 received 2.5% normal com. 5% treated group showed cancer promoting activity in rat liver using DEN as initiator and the induction of glutathione S-transferase placental form positive foci as an end point after 6 weeks of promotion.

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The Microbiological Assessment and Identification of Food Utensils and Food Service Facilities in School (학교 급식설비 및 집기류의 미생물학적 위해요소 분석)

  • Hong, Seung-Hee
    • Journal of Food Hygiene and Safety
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    • v.29 no.3
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    • pp.189-194
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    • 2014
  • This study was conducted to evaluate microorganism contamination of food utensils and service facilities in school and to prevent hazards by food poisoning occurrence. As a result, the highest number of microorganism growth plate ($12.3{\pm}2.6$) was detected in total bacteria test plate, and also observed $10.3{\pm}3.9$ growth plates in Staphylococcus aureus test plate and $9.5{\pm}3.9$ growth plates in E. coli and coliform bacteria test plate. But we could detect to the lowest number of growth plates ($1.5{\pm}1.0$) in Vibrio test plate. We also assessed that floors were appeared to the highest microorganism contamination rate in food utensils and service facilities. Therefore, $4.5{\pm}0.6$ growth plates was detected in pre-operation floor and $4.3{\pm}1.0$ growth plates in floor. And high level of microorganism contamination also observed in tables as $3.3{\pm}1.0$ growth plates in cooking table and $3.0{\pm}0.0$ growth plates in dining table. The level of microorganism contamination of food utensils such as kitchen knife, cutting board, and food tray were lower than that in food service facilities. We analysed microorganism contamination according to purpose of use in kitchen knifes and cutting boards. The microorganism contamination rate in fish kitchen knife ($2.0{\pm}0.8$) and fish cutting board ($1.3{\pm}1.5$) were slightly higher than that of others purpose of use. As a result of microorganism identification, various strains of microorganism were contaminated in food service facilities and some strains could detected more than two times. Especially, Staphylococcus aureus was repeatedly identified in cooking table, trench, and kitchen knife. Bacillus cereus was identified in kitchen knife, and then Pseudomonas fluorescens and Pseudomonas aeruginosa were also detected in food utensils and service facilities as known to food spoilage microorganisms. Klebsiella pneumoniae was detected four times repeat, which widely distribute natural environment as normal bacterial flora but sometimes cause acute pneumonia. These results suggest that food utensils and service facilities are contaminated with not only major food poisoning microorganisms such as Staphylococcus aureus, but also food spoilage microorganisms. Taken together, strict personal hygiene control and efficient food service facilities management will be needed to enhance food safety in school feeding and to improve student health.

Research on the Quality Characteristics of Domestic Colostrum according to the Processing Methods Employed (국내산 초유의 가공방법에 따른 품질특성 연구)

  • Jeong, Seok-Geun;Ham, Jun-Sang;Kim, Dong-Hun;Ahn, Chong-Nam;Chae, Hyun-Seok;You, Young-Mo;Jang, Ae-Ra;Kwon, Il-Kyung;Lee, Seung-Gyu
    • Food Science of Animal Resources
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    • v.29 no.4
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    • pp.457-465
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    • 2009
  • The characteristics of Holstein colostrum according to the methods that were employed in processing it were analyzed in this study to improve its industrial utilization. Colostrum samples were collected from the dairy farm of the National Institute of Animal Science (NIAS). The milk fat, protein, lactose, and SNF contents of colostrum were 4.34, 6.99, 3.37, and 11.10%, respectively. The effects of spray drying, freeze drying, freezing, acidification, and inoculation of lactic-acid bacteria on the characteristics of colostrum were then compared. The freezing of colostrum was found to be proper for long-term storage in a farm. Freeze-dried colostrum powder could not meet the processing requirements and the component standards for animal products in terms of the total bacterial and coliform bacteria counts, but spray-dried colostrum powder could meet the microbiological requirements because of its bactericidal effect during the spray-dry treatment. The inoculation of lactic-acid bacteria showed a better inhibitory effect on coliform than the acidification treatment, but protein precipitation appeared because of the low pH and the high acidity. To estimate the effects of the processing methods employed on the IgG of colostrum, the IgG contents of the milk treated by long temperature long time (LTLT) ($65^{\circ}C$, 30 min), by inoculating the lactic acid bacteria starter, by spray drying, and by freeze drying were measured. The IgG contents of the colostrum were changed significantly by the processing treatment employed, from 53.98 mg/mLto 33.28, 34.82, 21.98, and 36.89 mg/mL, respectively.

( Studies on the Grassland Development in the Forest II. Effect of fertilizer ievel on qrowth and dry matter yield of grass-clover mixtures grown under pine trees (임간초지 개발에 관한 연구 II. 임간혼파초지에서 3요소 시비수준이 목초의 생육과 수량에 미치는 영향)

  • Han, Y.C.;Park, M.S.;Seo, S.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.5 no.2
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    • pp.136-142
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    • 1985
  • For better grassland development in the forest, this field experiment was carried out to investigate the effect of thirteen different fertilizer levels of nitrogen(N), phosphorus ($P_2O_5$) and potassium ($K_2O$) on the botanical composition, growth and dry matter yield of grass-clover mixtures grown under trees with 40-50% of shading level. This experiment was arranged as a randomized block design with replications, and performed on the experimental field in the suburban forest of Suweon in 1984. The results obtained are summarized as follows: 1. Plant height and cover degree of grasses found to be high with 28 and 42kg N fertilizer per 10a, while those were the lowest with zero and N-zero fertilizer levels. The degree of bare land after the fourth cut was also high in the low N level. 2. A significant higher degree of leaf green and chlorophyll content of leaf blade was observed in the plot of 28 and 42 kg N per 10a when compared with low N fertilizer plot. However, leaf decay and plant type of grasses tended to be a little poor as the high N was applied. 3. the regrowth plant length and dry weight of grasses after the first cut increased significantly with 28 and 42 kg N fertilizer. However, those showed slightly increased regrowth in the plot of zero and N-zero fertilizer levels. 4. The dry matter yield of grasses was higher with 28 and 42 kg N than that of low N fertilizer level. Higher yields were obtained in the plot of standard ($N-P_2O_5-K_2O$=28-20-24 kg/10a), 50% increase of $N,P_2O_5K_2O$ and N-50% increase, although there were no significant differences among three fertilizer levels. 5. Growth, botanical composition, regrowth and yield of grasses grown under pine trees were significantly influenced by N fertilizer level, regardless of $P_2O_5\;and\;K_2O$. The fertilizer level of $N-P_2O_5-K_2O$ was 28-20-24 kg per 10a for more forage production in the forest. Considering economic yield in this study, however, the optimum fertilizer level of N, $P_2O_5\;and\;K_2O$ was suppose to be 21-28, 10-15, and 12-18kg per 10a, respectively.

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Summer-Autumn Growth Characteristics of Korean Lawn Grass in Response to Fertilizer Supply (시비에 따른 한국잔디의 하추기 생육특성에 관한 연구)

  • 심재성
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.4 no.3
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    • pp.206-211
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    • 1984
  • The influence of fertilizer on the growth characteristics in Korean lawn grass was studied from June through October in a experiment. The results were as follows: 1. Maximum dry matter weight of Korean lawn grass was achieved in early in early August when it was $64.3g/m^2$ without fertilizer and $157.9g/m^2$ with fertilizer. On the other hand, the dry matter weight of whole plant including Korean lawn grass reached the maximum in late September, which was late, to some extent, compared with that if pure Korean lawn grass, presumably associated with seed maturing period of $C_4$ type plants. 2. Notable positive effect on leaf blade and non-leaf part weight in Korean lawn grass was also detected. However, the rate of dry matter occupied by non-leaf part was markedly increased by fertilizer application. 3. The dry matter portion occupied by Korean lawn grass the in total dry matter weight of whole plant was significantly decreased as time went by, particularly in case of fertilizer application. 4. Fertilizer, which might imply an increased potential of tiller numbers according to fertilizer. 5. In general, the seasonal change pattern of the rhizome of Korean lawn grass coincided with that of the aboveground organs: Its maximum dry matter weight achieved from late August to early September was $194.2g/m^2$ with nil fertilizer, and, with fertilizer, $259.7g/m^2$, of which figures were equivalent to be increased to 33.7%, compared to that with nil fertilizer. Applying fertilizer increased the weight of root: The highest values were $36.7g/m^2$ with nil fertilizer and $80.9g/m^2$ with fertilizer.

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The Role of Initial Relative Renal Function in Unilateral Hydronephrosis (일측 폐색성 및 역류성 수신증에서 술전 상대적 신기능의 의미)

  • Han Sang-Won;Kang Seon-Jung;Kwon Min-Jung;Kim Dae-Joong;Choi Seung-Kang;Lee Tack
    • Childhood Kidney Diseases
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    • v.3 no.2
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    • pp.203-208
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    • 1999
  • Purpose: The information on the change of the relative renal function after operation is essential to set the initial treatment plan in unilateral hydronephrosis. So we analyzed the preoperative and postoperative relative renal function, and observed the functional changes by operation and reliability of the various factors in those changes. Materials and Methods: A retrospective trial was done of 81 patients, 35 ureteropelvic junction(UPJ) obstruction and 46 vesicoureteral reflux(VUR), among 393 patients undergoing operations at our institution from March. 1992 to February. 1997. The patients who had infravesical abnormalities, abnormal contralateral kidney and insufficient research data were excluded. We determined the relative renal functions using DTPA and MAG3 scan in UPJ obstruction and DMSA scan in VUR. The mean observation period after operation was 2.01(0.25-4) years. Results: A. UPJ Obstruction 1. The relative renal function was improved significantly after operation(P=0.0007). 2. The kidneys which have preoperative functions between 20% and 40% improved significantly in relative renal function comparing to the kidneys of the other functions(P=0.0046). B. VUR 1. The renal functions didn't improve significantly after operation(P>0.05). 2. There was no significant factor affecting the prognosis in renal functions. Conclusions: 1. The kidneys with UPJ Obstruction show the difference in functional improvement after operation according to the degree of the preoperative renal function, but more investigations about the exact value are needed. 2. In VUR there was no difference between preoperative and postoperative functions, the theoretical basis on objectives of the operation could be the symptoms or factors except the operation.

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Comparison of X-ray VCUG with RI VCUG for Diagnosing VUR in Children (소아의 방광 요관 역류 진단시 X-ray 배뇨성 방광 요도 조영술(X-ray VCUG)과 방사성 동위원소 배뇨성 방광 요도 조영술(RI VCUG)의 비교)

  • Hong Hyun-Soook;Choi Deuk-Lin;Kim Eun-Mi;Kim Sung-Jun
    • Childhood Kidney Diseases
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    • v.3 no.2
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    • pp.187-195
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    • 1999
  • Purpose : VUR is state where urine regurge from bladder to ureter and kidney. It is shown in about 1/3 of urinary tract infection patients and it is classified as grade I to V. We compared results from RI VCUG(Radiisotope voiding cystourethrography) and X-ray VCUG which used in diagnosing VUR in children, to evaluate which is better in diagnosing VUR in children. Methods : 41 Patients(19 males, 21 females), who visited Pediatric department, Soonchunhyang university Hospital from peroid of 1991. January to 1998. July for recurrent urinary tract infection or abnormalities in ultrasonogams, were enrolled in the study. The age ranged from 9 months to 17 years and mean age was 5 1/2 years. Both RI VCUG and X-ray VCUG were done and follow-up test of urine culture, renal ultrasonogram and RI VCUG were done every month, every 3 month and every 6 month, respectively to observe the disappearance of VUR and evaluated the prognosis. Results : 24 patients had taken RI VCUG and 17(70.1%) patients showed positive result. 22 patients had taken X-ray VCUG and 9(40.1%) patients showed findings of VUR. 17 patients had taken both tests and 14 patients showed positive result in RI VCUG and 6 of these patients also showed reflux in X-ray VCUG. 3 patients who showed negative in RI VCUG, showed negative also in X-ray VCUG. For prognosis, resolution and scar formation was shown in 8 patients each. Persistent VUR was shown in 6 patients and 2 of these patients VUR was corrected by operation, 1 patient showed decreased renal function, and 1 patient was not follwed up. 8 of 9 patients who showed findings of VUR on DMSA scan formed a scar and 8 patients who showed no findings of VUR didn't form a scar. Urine culture was positive in 17 of 19 patients with VUR. Positive rate in urine culture was higher than that of patients with no VUR who showed positivity in 15 of 21 patients for urine culture. E. coli was most common organism and the period free of UTI was 14 months in VUR patients and it was shorter compared to patients without VUR which was 26 months. Conclusion : In diagnosing VUR in children, the positive rate was higher in RI VCUG than X-ray VCUG. Therefore, in early diagnosis when VUR is suspicious but not shown in X-ray VCUG, RI VCUG should be done and it will help to make accurate diagnosis.

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Comparision of Maternal Charcteristics and Birth Weight among Five Different Categories of Medical Facility for Delivery in Taegu (대구시내 각급 의료기관에서 분만하는 산모들의 특성 및 출산결과의 비교 분석)

  • Song, Jung-Hup;Park, Jung-Han;Kim, Gui-Yeon;Kim, Jang-Rak
    • Journal of Preventive Medicine and Public Health
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    • v.21 no.1 s.23
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    • pp.10-20
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    • 1988
  • This study was conducted to compare the maternal charactristics, and birth weight of infants delivered at five different categories of medical facility in Taegu to examine the risk level of pregnant women and children by the medical facility for delivery. The study population included 1,410 pregnant women who delivered a baby at one of nine medical facilities (3 university hospitals, 2 general hospitals, 2 private clinics, 1 midwife clinic, 1 MCH center) in Taegu in April, 1987(April and May, 1987 for K university hospital), Pregnant women were interviewed to ask the age and educational level of woman, payment of medical fee, birth order, delivery method. Birth weight of infant was obtained from medical record. Mean ages of the women delivering at the university hospitals(27.5 years) and at general hospitals(26.7 years) were higher than those at midwife clinic(25.4 years) and at MCH center(26.1 years). Also, mean years of school education were higher in women of university hospitals(12.7 years) and general hospitals (12.2 years) than in women of midwife clinic(9.2 years) and MCH center (9.3 years). The percentages of women covered by the medical insurance were far greater in the university hospitals(78.1%) and general hospitals(82.9%) than in private clinics(44.3%) , midwife clinic(29.1%) and MCH center (5.4%). Infants born at the MCH center were mostly the second birth (47.3%) while 56.0% to 61.7% of infants born at all the other medical facilities were the first birth more women delivering at the university hospitals had history of spontaneous abortion as well as still birth than the women delivering at the other medical facilities. The preform birth rate (11.4%) and low birthweight incidence rates(5.8-13.0%) in university hospitals were significantly higher than those of other medical facilities. Accordingly, c-section rates showed a wide variation among the medical facilities. Study findings revealed that most of women delivering at the university hospitals and general hospitals are in the middle of or upper socio-economic class and obstetrically high risk group regardless of socioeconomic class while the wome delivering at the midwife clinic and MCH center are low risk group of low socioeconomic class. Therefore, the data of a specific medical facility are highly limited in interpretation and can not be generalized.

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Ceftriaxone Associated Biliary Pseudolithiasis (Ceftriaxone 사용후 발생된 Pseudolithiasis)

  • Kim, Jae-Young;Ko, Jae-Sung;Lee, Hwan-Jong;Ko, Young-Ryul;Seo, Jeong-Kee
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.1 no.1
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    • pp.100-106
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    • 1998
  • Purpose: Ceftriaxone, a potent parenteral third-generation semisynthetic cephalosporin is widely used for the treatment of a variety of bacterial infections in both children and adult. Review of recent data indicates that ceftriaxone treatment has been associated with the development of reversible biliary pseudolithiasis and that is thought by many to be a benign process. Despite, several reports describe patients with ceftriaxone pseudolithiasis who required cholecystectomy for presumed acute cholecystitis. In this study we evaluated the incidence, risk factors, and prognosis of gallbladder pseudolithiasis after ceftriaxone treatment. Methods: Between march, 1997 and January, 1998, any child admitted to the Children's hospital of National University of Seoul and prescribed ceftriaxone for probable or definite bacterial infection were eligible for the study. 21 of them had ultrasound examination on the 2~12 days later after the start of ceftriaxone treatment, 8 of whom documented gallbladder precipitates or pseudolithiasis during treatment by serial abdominal ultrasound. Repeat abdominal ultrasound was performed 10~80 days later after the end of ceftriaxone treatment. The children with underlying liver disease or decreased renal function were excluded in this study. Results: 1) 21 children had ultrasound examinations of gallbladder during ceftriaxone treatment and 8 (38%) of them acquired pseudolithiasis. 2) The patients who developed gallbladder pseudolithiasis were significantly older ($6.3{\pm}2.9$ yr. vs $2.2{\pm}3.1$ yr.)(p<0.05), and older than 24 months were probably the significant risk associated with this phenomenon (p<0.05). However, no significant differences in sex, type of infection, fasting, and ceftriaxone treatment regimen (dose, duration of therapy). 3) The abnormality found on gallbladder ultrasonography was a strikingly hyperechogenic material with post-acoustic shadowing in 5 patients without post-acoustic shadowing in 3 patients 4) Follow up of gallbladder ultrasound was performed in 6 patients after cessation of ceftriaxone treatment. Sonographic abnormalities completely resolved within 14 days post cessation of therapy in 2 patients; 30 days, 1 patient; 80 days, 3 patients. Conclusions: We suggest that routine abdominal ultrasound should be considered in all children who received high dose ceftriaxone in more than 24 months of age and developed hepatobiliary symptoms during or just after ceftriaxone treatment.

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