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Study on Intestinal Viability and Optimum Feeding Method of Lactobacillus in Broiler Chickens (육계에 대한 유산균의 장내 생존성 및 적정 급여방법에 대한 연구)

  • Kim, Dong-Wook;Kim, Ji-Hyuk;Kang, Geun-Ho;Kang, Hwan-Ku;Lee, Sang-Jin;Lee, Won-Jun;Kim, Sang-Ho
    • Journal of Animal Science and Technology
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    • v.50 no.6
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    • pp.807-818
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    • 2008
  • This study was conducted to prove the optimum feeding method of Lactobacillus in broiler chickens by investigating the intestinal viability of ingested Lactobacillus and the effect of feeding levels and frequency of Lactobacillus on growth performance in broiler chickens. In experiment 1, A total of one hundred, 5 weeks old male broiler chickens(Abor Acre) were fed Lactobacillus reuteri avibro2 expressed green fluorescent protein(GFP) at 104cfu/g diet to investigate the retention time of ingested Lactobacillus in the intestine for 1 day. The percentage of Lactobacillus expressed GFP in intestinal contents was 26% at 1 day after fed Lactobacillus expressed GFP. The percentage of Lactobacillus expressed GFP in intestinal contents was decreased in length of time. In experiment 2, A total of four hundred eighty, 1-d-old male broiler chicks(Abor Acre) were randomly divided into 4 groups with 4 replicates of 30 birds each to prove the optimum feeding level of Lactobacillus. The treatments were control(free antibiotics), Lactobacillus reuteri avibro2 5.0×10cfu/mL, 5.0×103cfu/mL, and 5.0×105cfu/mL. The final body weight and body wight gain of Lactobacillus reuteri avibro2 5.0×103cfu/mL were the highest in all groups(P<0.05). Feed conversion ratio was not significantly difference among the groups. The number of intestinal lactic acid bacteria in Lactobacillus treated groups tended to be improved or significantly increased as compared to that of control(P<0.05). Protein and fat digestibility in Lactobacillus 5.0×103cfu/mL and 5.0×105cfu/mL treated groups were significantly improved(P<0.05). No significant differences were observed on the availability of dry matter and crude ash in Lactobacillus treatments compared to those of control. In experiment 3, A total of six hundred 1-d-old male broiler chicks(Abor Acre) were randomly divided into 4 groups with 4 replicates of 30 birds each and were fed Lactobacillus reuteri avibro2 at intervals of 1, 2, 3, and 5 day for five weeks. Feeding level of Lactobacillus was 5.0×103cfu/mL The final body weight and body wight gain of Lactobacillus reuteri avibro2 5.0×103cfu/mL were the highest in all groups(P<0.05). The final body weight and body weight gain were significantly increased, when Lactobacillus was fed at intervals of 1 days, or 2 days. There were no significant differences in feed intake and feed conversion ratio among the all groups. The number of intestinal lactic acid bacteria in Lactobacillus treated groups tended to be improved or significantly increased as compared to that of control(P<0.05). No significant differences were observed on the number of coliform bacteria and Salmonella of ileum and cecum. Consequently, supplemental Lactobacillus influenced positive effects on the growth performance, nutrient availability and intestinal microflora. The optimum feeding level of Lactobacillus was 5.0×103cfu/mL, and the constant feeding of Lactobacillus was effective.

Preparation and Characterization of Physicochemical and Sensory Properties of Bread Enriched with Two Types of Wild Grape Extract (제조방법이 다른 두 종류의 머루즙 첨가가 빵의 이화학적 및 관능적 특성에 미치는 영향)

  • Lee, Byung-Yong;Lee, Malp-Eum;O, Jin-Hwan;Kim, Eun-Cho;Surh, Jeong-Hee
    • Korean journal of food and cookery science
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    • v.26 no.5
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    • pp.636-648
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    • 2010
  • Two types of wild grape extracts(WGE) prepared by different methods were added into butter-top bread at different concentrations(0, 5, 10, 15, 20% of water). Then, the resulting breads were analyzed for their physicochemical and sensory properties in order to identify whether or not the WGE-enriched breads were comparable to control bread in terms of qualities and preferences. Wild grape sugar mixture(WGS), which was prepared by osmotic dehydration of wild grape fruits with the same amounts of sugar, presented significantly lower moisture content and titratable acidity as well as higher pH and sugar content compared to wild grape juice(WGJ), which was produced by boiling the fruits in a vacuum jar and squeezing. The pH of the doughs and breads containing WGE tended to decrease with increasing amounts of WGE, and this phenomenon was more appreciable in those containing WGJ than WGS. This was presumably due to the higher contents of tartaric acid in WGJ. For both types of extracts, hardness, gumminess, and chewiness of the doughs decreased with the addition of WGE, nevertheless, which properties were not remained in the resulting breads. This could be partially attributed to the relatively high degree of baking loss and lower pH of the WGE-enriched breads than those of control bread. Contrary to the mechanical analyses, the sensory properties of the breads were dependent on the WGE type. That is, WGJ-enriched bread showed lower consistency and moistness than control bread, which consequently led to relatively lower overall acceptability. However, WGS addition did not adversely affect the sensory properties of the bread. In particular, addition of 5% WGS somewhat improved the physical and sensory qualities of the bread. Thus, WGE-enriched bread could be produced without loss of bread quality when prepared with 5% WGS.

The difference of image quality using other radioactive isotope in uniformity correction map of myocardial perfusion SPECT (심근 관류 SPECT에서 핵종에 따른 Uniformity correction map 설정을 통한 영상의 질 비교)

  • Song, Jae hyuk;Kim, Kyeong Sik;Lee, Dong Hoon;Kim, Sung Hwan;Park, Jang Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.2
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    • pp.87-92
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    • 2015
  • Purpose When the patients takes myocardial perfusion SPECT using $^{201}Tl$, the operator gives the patients an injection of $^{201}Tl$. But the uniformity correction map in SPECT uses $^{99m}Tc$ uniformity correction map. Thus, we want to compare the image quality when it uses $^{99m}Tc$ uniformity correction map and when it uses $^{201}Tl$ uniformity correction map. Materials and Methods Phantom study is performed. We take the data by Asan medical center daily QC condition with flood phantom including $^{201}Tl$ 21.3 kBq/mL. After postprocessing with this data, we analyze CFOV integral uniformity(I.U) and differential uniformity(D.U). And we take the data with Jaszczak ECT Phantom by American college of radiology accreditation program instruction including $^{201}Tl$ 33.4 kBq/mL. After post processing with this data, we analyze spatial Resolution, Integral Uniformity(I.U), coefficient of variation(C.V) and Contrast with Interactive data language program. Results In the flood phantom test, when it uses $^{99m}Tc$ uniformity correction map, Flood I.U is 3.6% and D.U is 3.0%. When it uses $^{201}Tl$ uniformity correction map, Flood I.U is 3.8% and D.U is 2.1%. The flood I.U is worsen about 5%, but the D.U is improved about 30% inversely. In the Jaszczak ECT phantom test, when it uses $^{99m}Tc$ uniformity correction map, SPECT I.U, C.V and contrast is 13.99%, 4.89% and 0.69. When it uses $^{201}Tl$ uniformity correction map, SPECT I.U, C.V and contrast is 11.37%, 4.79% and 0.78. All of data are improved about 18%, 2%, 13% The spatial resolution was no significant changes. Conclusion In the flood phantom test, Flood I.U is worsen but Flood D.U is improved. Therefore, it's uncertain that an image quality is improved with flood phantom test. On the other hand, SPECT I.U, C.V, Contrast are improved about 18%, 2%, 13% in the Jaszczak ECT phantom test. This study has limitations that we can't take all variables into account and study with two phantoms. We need think about things that it has a good effect when doctors decipher the nuclear medicine image and it's possible to improve the image quality using the uniformity correction map of other radionuclides other than $^{99m}Tc$, $^{201}Tl$ when we make other nuclear medicine examinations.

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The Comparison of Quantitative Indices by Changing an Angle of LAO View in Multi-Gated Cardiac Blood Pool Scan (게이트 심장 혈액풀 스캔에서 좌전사위상 각도의 변화에 따른 정량적 지표 비교)

  • Yoon, Soon-Sang;Nam, Ki-Pyo;Ryu, Jae-Kwang;Kim, Seong-Hwan
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.1
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    • pp.57-61
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    • 2012
  • Purpose: The multi-gated cardiac blood pool scan is to evaluate the function of left ventricle (LV) and usefully observe a value of ejection fraction (EF) for a patient who is receiving chemotherapy. To calculate LVEF, we should adjust an angle of left anterior oblique (LAO) view to separate both ventricles. And by overlapped ventricles, it is possible to affect LVEF. The purpose of this study is to investigate and compare quantitative indices by changing an angle of LAO view. Materials and methods: We analyzed the 49 patients who were examined by multi-gated cardiac blood pool scan in department of nuclear medicine at Asan Medical Center from June to September 2011. Firstly, we acquired "Best septal" view. And then, we got images by addition and subtraction of angle for LAO view to anterior and lateral. We compared three LAO views for 20 people by 5 degrees and 39 people by 10 degrees. And we analyzed quantitative indices, EF, end diastole and end systole counts, by automated and manual region of interest (ROI) modes. Results: Firstly, we analyzed quantitative indices by automated ROI mode. In case of 5 degrees, the averages of EF are $61.0{\pm}7.5$, $62.1{\pm}7.1$, $60.9{\pm}6.7%$ ($p$=0.841) in LAO, LAO $-5^{\circ}$ and LAO $+5^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). In case of 10 degrees, the averages of EF are $62.4{\pm}9.5$, $62.3{\pm}10.8$, $61.6{\pm}.9.3%$ ($p$=0.938) in LAO, LAO $-10^{\circ}$ and LAO $+10^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). Secondly, we analyzed quantitative indices by manual ROI mode. In case of 5 degrees, the averages of EF are $62.8{\pm}7.1$, $63.6{\pm}7.5$, $62.7{\pm}7.3%$ ($p$=0.903) in LAO, LAO $-5^{\circ}$ and LAO $+5^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). In case of 10 degrees, the averages of EF are $65.5{\pm}9.0$, $66.3{\pm}8.7$, $63.5{\pm}.9.3%$ (p=0.473) in LAO, LAO $-10^{\circ}$ and LAO $+10^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). Conclusion: When an image is nearly "Best septal" view, the difference of LAO angle would not affect to change LVEF. Although there was no difference in quantitative analysis, deviations could happen when to interpret wall motion qualitatively by reading physicians.

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Application of Westgard Multi-Rules for Improving Nuclear Medicine Blood Test Quality Control (핵의학 검체검사 정도관리의 개선을 위한 Westgard Multi-Rules의 적용)

  • Jung, Heung-Soo;Bae, Jin-Soo;Shin, Yong-Hwan;Kim, Ji-Young;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.1
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    • pp.115-118
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    • 2012
  • Purpose: The Levey-Jennings chart controlled measurement values that deviated from the tolerance value (mean ${\pm}2SD$ or ${\pm}3SD$). On the other hand, the upgraded Westgard Multi-Rules are actively recommended as a more efficient, specialized form of hospital certification in relation to Internal Quality Control. To apply Westgard Multi-Rules in quality control, credible quality control substance and target value are required. However, as physical examinations commonly use quality control substances provided within the test kit, there are many difficulties presented in the calculation of target value in relation to frequent changes in concentration value and insufficient credibility of quality control substance. This study attempts to improve the professionalism and credibility of quality control by applying Westgard Multi-Rules and calculating credible target value by using a commercialized quality control substance. Materials and Methods : This study used Immunoassay Plus Control Level 1, 2, 3 of Company B as the quality control substance of Total T3, which is the thyroid test implemented at the relevant hospital. Target value was established as the mean value of 295 cases collected for 1 month, excluding values that deviated from ${\pm}2SD$. The hospital quality control calculation program was used to enter target value. 12s, 22s, 13s, 2 of 32s, R4s, 41s, $10\bar{x}$, 7T of Westgard Multi-Rules were applied in the Total T3 experiment, which was conducted 194 times for 20 days in August. Based on the applied rules, this study classified data into random error and systemic error for analysis. Results: Quality control substances 1, 2, and 3 were each established as 84.2 ng/$dl$, 156.7 ng/$dl$, 242.4 ng/$dl$ for target values of Total T3, with the standard deviation established as 11.22 ng/$dl$, 14.52 ng/$dl$, 14.52 ng/$dl$ respectively. According to error type analysis achieved after applying Westgard Multi-Rules based on established target values, the following results were obtained for Random error, 12s was analyzed 48 times, 13s was analyzed 13 times, R4s was analyzed 6 times, for Systemic error, 22s was analyzed 10 times, 41s was analyzed 11 times, 2 of 32s was analyzed 17 times, $10\bar{x}$ was analyzed 10 times, and 7T was not applied. For uncontrollable Random error types, the entire experimental process was rechecked and greater emphasis was placed on re-testing. For controllable Systemic error types, this study searched the cause of error, recorded the relevant cause in the action form and reported the information to the Internal Quality Control committee if necessary. Conclusions : This study applied Westgard Multi-Rules by using commercialized substance as quality control substance and establishing target values. In result, precise analysis of Random error and Systemic error was achieved through the analysis of 12s, 22s, 13s, 2 of 32s, R4s, 41s, $10\bar{x}$, 7T rules. Furthermore, ideal quality control was achieved through analysis conducted on all data presented within the range of ${\pm}3SD$. In this regard, it can be said that the quality control method formed based on the systematic application of Westgard Multi-Rules is more effective than the Levey-Jennings chart and can maximize error detection.

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Usefulness Evaluation of Open Mouth View when PET/CT scan In Tongue Cancer Patients (Tongue Cancer 환자에서 PET/CT 검사 시 Open Mouth 촬영법의 유용성 평가)

  • Kim, Jae Hwan;Yun, Jong Jun;Jung, Ji Wook;Kim, Jung Wook;Hwang, Ju Won;Ji, Hye In
    • The Korean Journal of Nuclear Medicine Technology
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    • v.20 no.2
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    • pp.14-20
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    • 2016
  • Purpose Tongue cancer is 1.8% of all cancer tumors occur in the tongue, it is known that the high incidence enough to account for 75% of oral cancer conducted a PET / CT examination for early diagnosis, metastasis, staging, etc. and. Tongue when PET / CT scan of a cancer patient and a Torso taken to close mouth lesions if the condition was caused due to the overlapping or corresponding artifacts are not clearly observed. The purpose of this study is to evaluate the changes that occur during PET / CT scan with open mouth and its usefulness under. Materials and Methods From June 2015 to March 2016 complained of herein by May 21 had received a diagnosis of tongue cancer underwent PET / CT scan patients were treated with a target (16 males, 5 female). The first was taken to close mouth Torso state, it was taken to add 1 bed open mouth condition. Tumor (T), measuring the Normal Tongue (NT), Lymph Node (LN) standard intake coefficient by setting a region of interest in the (standardized uptake value, SUV) SUVmean, the average value was measured SUVmax, drawn to each region of interest 3 times and Background (Carotid artery) was out of the SUV. In Chapter 3 of the slice to the tumor clearly visible by setting the region of interest to measure the change Tumor size was calculated average value. Gross Image resolution assessment were analyzed statistically through were divided into 1-5 points by the Radiation 7 people in 2, more than five years worked in specialized nuclear medicine compare to proceed with the blind test nonparametric test (wilcoxon signed rank test). (SPSS ver.18) Results $SUV_{mean}$ T's were in close mouth $5.01{\pm}2.70$ with open mouth $5.48{\pm}2.88$ (P<0.05), $SUV_{max}$ were respectively $8.78{\pm}5.55$ and $9.70{\pm}5.99$ (P<0.05). $SUV_{mean}$ in the NT were respectively $0.43{\pm}0.30$ and $0.34{\pm}0.24$ (P=0.20), $SUV_{max}$ was $0.56{\pm}0.34$ and $0.45{\pm}0.25$ (P=0.204). LN $SUV_{mean}$ were respectively $1.62{\pm}1.43$ and $1.69{\pm}1.49$ (P=0.161), $SUV_{mean}$ was $2.09{\pm}1.88$ and $1.99{\pm}1.74$ (P=0.131). Tumor size change is close mouth $4.96{\pm}4.66cm^2$ $5.33{\pm}4.64cm^2$ with 7.45% increase was (P<0.05), gross image resolution evaluation is $2.87{\pm}0.73$, $3.77{\pm}0.68$ with open mouth examinations 30.5% increase was (P<0.05). Conclusion Tumor SUV on the changes that had an increase in open mouth during inspection, the normal tongue and lymph node, but there was no significant difference in the change slightly. It is also one open mouth PET / CT scan will provide improved image to all patients with tongue cancer, but it could be confirmed that similar overall through the blind test, or tumor size changes and showing a high resolution image. It can be the perfect alternative method for problems that occur when the close mouth Open mouth PET / CT scan, but is believed to be through the open mouth to observe the boundary of overlapping or tumor of the oral cavity other structures a little more clearly. Tongue cancer patients how to recommend that the shooting further open mouth PET / CT.

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CComparative evaluation of the methods of producing planar image results by using Q-Metrix method of SPECT/CT in Lung Perfusion Scan (Lung Perfusion scan에서 SPECT-CT의 Q-Metrix방법과 평면영상 결과 산출방법에 대한 비교평가)

  • Ha, Tae Hwan;Lim, Jung Jin;Do, Yong Ho;Cho, Sung Wook;Noh, Gyeong Woon
    • The Korean Journal of Nuclear Medicine Technology
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    • v.22 no.1
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    • pp.90-97
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    • 2018
  • Purpose The lung segment ratio which is obtained through quantitative analyses of lung perfusion scan images is calculated to evaluate the lung function pre and post surgery. In this Study, the planar image production methods by using Q-Metrix (GE Healthcare, USA) program capable of not only quantitative analysis but also computation of the segment ratio after having performed SPECT/CT are comparatively evaluated. Materials and Methods Lung perfusion scan and SPECT/CT were performed on 50 lung cancer patients prior to surgery who visited our hospital from May 1, 2015 to September 13, 2016 by using Discovery 670(GE Healthcare, USA) equipment. AP(Anterior Posterior)method that uses planar image divided the frontal and rear images into three rectangular portions by means of ROI tool while PO(Posterior Oblique)method computed the segment ratio by dividing the right lobe into three parts and the left lobe into two parts on the oblique image. Segment ratio was computed by setting the ROI and VOI in the CT image by using Q-Metrix program and statistically analysis was performed with SPSS Ver. 23. Results Regarding the correlation concordance rate of Q-Metrix and AP methods, RUL(Right upper lobe), RML(Right middle lobe) and RLL(Right lower lobe) were 0.224, 0.035 and 0.447. LUL(Left upper lobe) and LLL(Left lower lobe) were found to be 0.643 and 0.456, respectively. In the PO method, the right lobe were 0.663, 0.623 and 0.702, respectively, while the left lobe were 0.754 and 0.823. When comparison was made by using the Paired sample T-test, Right lobe were $11.6{\pm}4.5$, $26.9{\pm}6.2$ and $17.8{\pm}4.2$, respectively in the AP method. Left lobe were $28.4{\pm}4.8$ and $15.4{\pm}5.6$. The right lobe of PO had values of $17.4{\pm}5.0$, $10.5{\pm}3.6$ and $27.3{\pm}6.0$, while the left lobe had values of $21.6{\pm}4.8$ and $23.1{\pm}6.6$, thereby having statistically significant difference in comparison to the Q-Metrix method for each of the lobes (P<0.05). However, there was no statistically significant difference in Right middle lobe (P>0.05). Conclusion The AP method showed low concordance rate in correlation with the Q-Metrix method. However, PO method displayed high concordance rate overall. although AP method had significant differences in all lobes, there was no significant difference in Right middle lobe of PO method. Therefore, at the time of production of lung perfusion scan results, utilization of Q-Metrix method of SPECT/CT would be useful in computation of accurate resultant values. Moreover, it is deemed possible to expect obtain more practical sectional computation result values by using PO method at the time of planar image acquisition.

Study of nosocomial rotavirus infection in neonates admitted to a postpartum-care center (서울시내 1개 산후 조리원에서 시행한 로타바이러스 선별검사에 대한 분석)

  • Park, Ji Young;Kim, Dong Hwan;Bae, Seung Young;Choi, Chang Hee;Cho, Eun Young;Choi, Jeong Hoon;Kim, Sun Mi
    • Pediatric Infection and Vaccine
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    • v.14 no.2
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    • pp.145-154
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    • 2007
  • Purpose : Rotavirus is one of the most important etiologic agents of nosocomial infections among the neonates. This study was designed to investigate nosocomial rotavirus infection in neonates who were admitted to a postpartum-care center after birth. Methods : From March 2005 to September 2006, 957 healthy neonates were examined for rotavirus antigen in stool by immunochromatographic method and 216 neonates were rotavirus antigen positive within 24 hours after admitted to a postpartum-care center. We reviewed the nursing charts retrospectively such as characteristics, monthly distribution, birth hospitals, delivery methods, feeding types and clinical manifestations. Results : Among 957 neonates, 216 neonates (22.6%) were rotavirus antigen positive and there were no differences in sex, birth weight, gestational age. Monthly positive rate of rotavirus antigen showed diversity from 10% to 36%. According to birth hospitals, positive rate showed diversity from 3.5% to 53.6%. Out of 957 neonates, 655 cases (68.4%) were born of vaginal delivery and mean hospitalized duration was 2.4 days, 302 cases (31.6%) were born of cesarean section and mean hospitalized duration was 5.7 days. 17.6% of vaginal delivery and 33.4% of cesarean section were rotavirus antigen positive. The positive rate was higher in neonates by cesarean section than vaginal delivery (P<0.001). According to feeding types, positive rate of rotavirus antigen was lower in breast-fed group than formula-fed group (P<0.001). Proportion of symptomatic case among rotavirus antigen positive was 34.7%. Most common clinical manifestation was diarrhea (61.3%), following poor feeding (45.3%), fever (40.0%), vomiting (25.3%), delayed weight gain (12.0%), and decreased urine amount (5.3%). Conclusion : Some neonates were already infected before admission to a postpartum-care center. Without meticulous management, nosocomial rotavirus infection would transmit rapidly in a postpartum-care center spreading to the community. Recommendation of breast-feeding, routine rotavirus screeing test with or without symptom, and isolation of all rotavirus antigen positive neonates in a postpartum-care center seem to be necessary. Also attentive hygiene education and further investigations of rotavirus infection in a postpartum-care center would be needed.

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Dosimetric Characteristics of Detectors in Measurement of Beam Data for Small Fields of Linear Accelerator (선형가속기의 소조사면에 대한 빔 자료 측정에서 검출기의 선량 특성 분석)

  • Koo, Ki-Lae;Yang, Oh-Nam;Lim, Cheong-Hwan;Choi, Won-Sik;Shin, Seong-Soo;Ahn, Woo-Sang
    • Journal of radiological science and technology
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    • v.35 no.3
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    • pp.265-273
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    • 2012
  • Aquisition of accurate beam data is very important to calculate a reliable dose distribution of the treatment planning system for small radiation fields in intensity-modulated radiation therapy(IMRT) and stereotactic radiosurgery(SRS). For the measurement of small fields, the choice of a suitable detector is important due to the shape gradient in profile penumbra, the lack of lateral electronic equilibrium, and the effect of effective detector volume. Therefore, this study was to analyze the dosimetric characteristics of various detectors in measurement of beam data for small fields of linear accelerator. 0.01cc and 0.13cc ion chambers (CC01 and CC13) and a stereotactic diode detector(SFD) were used for measurement of small fields. The beam data, including the percent depth dose, output factor, and beam profile were acquired under 6 MV and 15 MV photon beams. Measurements were performed with the field size ranging from $2{\times}2cm^2$ to $5{\times}5cm^2$. For $2{\times}2cm^2$ field size, the differences of the ratios of $PDD_{20}$ and $PDD_{10}$ measured by CC01 and SFD detectors were 1.02% and 0.12% for 6 MV and 15 MV photon beams, respectively. For field sizes larger than $3{\times}3cm^2$, the differences of values of $PDD_{20}/PDD_{10}$ obtained from each detector were 1.15% and 0.71% for 6 MV and 15 MV photon beams, respectively. The output factors obtained from CC01 and SFD for $2{\times}2cm^2$ field size were within 0.5% and 1.5% for 6 MV and 15 MV, respectively. The differences in output factor of three detectors for $3{\times}3cm^2$ to $5{\times}5cm^2$ field sizes were within 0.5%. Profile penumbras measured by the SFD, CC01, and CC13 detectors at three depths were average 2.7 mm and 3.5 mm, 3.4 mm and 4.3 mm, and 5.2 mm and 6.1 mm for 6 MV and 15 MV photon beams, respectively. In conclusion, it could be possible to use of the CC01 and SFD detectors for the measurement of percent depth dose and output factor for $2{\times}2cm^2$ field size, and to use of three detectors for $3{\times}3cm^2$ to $5{\times}5cm^2$ field sizes. CC01 and SFD detectors, consider ably smaller than the radiation field, should be used in order to accurately measure the profile penumbra for small field sizes.

A Study on the Observation of Soil Moisture Conditions and its Applied Possibility in Agriculture Using Land Surface Temperature and NDVI from Landsat-8 OLI/TIRS Satellite Image (Landsat-8 OLI/TIRS 위성영상의 지표온도와 식생지수를 이용한 토양의 수분 상태 관측 및 농업분야에의 응용 가능성 연구)

  • Chae, Sung-Ho;Park, Sung-Hwan;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
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    • v.33 no.6_1
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    • pp.931-946
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    • 2017
  • The purpose of this study is to observe and analyze soil moisture conditions with high resolution and to evaluate its application feasibility to agriculture. For this purpose, we used three Landsat-8 OLI (Operational Land Imager)/TIRS (Thermal Infrared Sensor) optical and thermal infrared satellite images taken from May to June 2015, 2016, and 2017, including the rural areas of Jeollabuk-do, where 46% of agricultural areas are located. The soil moisture conditions at each date in the study area can be effectively obtained through the SPI (Standardized Precipitation Index)3 drought index, and each image has near normal, moderately wet, and moderately dry soil moisture conditions. The temperature vegetation dryness index (TVDI) was calculated to observe the soil moisture status from the Landsat-8 OLI/TIRS images with different soil moisture conditions and to compare and analyze the soil moisture conditions obtained from the SPI3 drought index. TVDI is estimated from the relationship between LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index) calculated from Landsat-8 OLI/TIRS satellite images. The maximum/minimum values of LST according to NDVI are extracted from the distribution of pixels in the feature space of LST-NDVI, and the Dry/Wet edges of LST according to NDVI can be determined by linear regression analysis. The TVDI value is obtained by calculating the ratio of the LST value between the two edges. We classified the relative soil moisture conditions from the TVDI values into five stages: very wet, wet, normal, dry, and very dry and compared to the soil moisture conditions obtained from SPI3. Due to the rice-planing season from May to June, 62% of the whole images were classified as wet and very wet due to paddy field areas which are the largest proportions in the image. Also, the pixels classified as normal were analyzed because of the influence of the field area in the image. The TVDI classification results for the whole image roughly corresponded to the SPI3 soil moisture condition, but they did not correspond to the subdivision results which are very dry, wet, and very wet. In addition, after extracting and classifying agricultural areas of paddy field and field, the paddy field area did not correspond to the SPI3 drought index in the very dry, normal and very wet classification results, and the field area did not correspond to the SPI3 drought index in the normal classification. This is considered to be a problem in Dry/Wet edge estimation due to outlier such as extremely dry bare soil and very wet paddy field area, water, cloud and mountain topography effects (shadow). However, in the agricultural area, especially the field area, in May to June, it was possible to effectively observe the soil moisture conditions as a subdivision. It is expected that the application of this method will be possible by observing the temporal and spatial changes of the soil moisture status in the agricultural area using the optical satellite with high spatial resolution and forecasting the agricultural production.