• Title/Summary/Keyword: materials science

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Increase of Tc-99m RBC SPECT Sensitivity for Small Liver Hemangioma using Ordered Subset Expectation Maximization Technique (Tc-99m RBC SPECT에서 Ordered Subset Expectation Maximization 기법을 이용한 작은 간 혈관종 진단 예민도의 향상)

  • Jeon, Tae-Joo;Bong, Jung-Kyun;Kim, Hee-Joung;Kim, Myung-Jin;Lee, Jong-Doo
    • The Korean Journal of Nuclear Medicine
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    • v.36 no.6
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    • pp.344-356
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    • 2002
  • Purpose: RBC blood pool SPECT has been used to diagnose focal liver lesion such as hemangioma owing to its high specificity. However, low spatial resolution is a major limitation of this modality. Recently, ordered subset expectation maximization (OSEM) has been introduced to obtain tomographic images for clinical application. We compared this new modified iterative reconstruction method, OSEM with conventional filtered back projection (FBP) in imaging of liver hemangioma. Materials and Methods: Sixty four projection data were acquired using dual head gamma camera in 28 lesions of 24 patients with cavernous hemangioma of liver and these raw data were transferred to LINUX based personal computer. After the replacement of header file as interfile, OSEM was performed under various conditions of subsets (1,2,4,8,16, and 32) and iteration numbers (1,2,4,8, and 16) to obtain the best setting for liver imaging. The best condition for imaging in our investigation was considered to be 4 iterations and 16 subsets. After then, all the images were processed by both FBP and OSEM. Three experts reviewed these images without any information. Results: According to blind review of 28 lesions, OSEM images revealed at least same or better image quality than those of FBP in nearly all cases. Although there showed no significant difference in detection of large lesions more than 3 cm, 5 lesions with 1.5 to 3 cm in diameter were detected by OSEM only. However, both techniques failed to depict 4 cases of small lesions less than 1.5 cm. Conclusion: OSEM revealed better contrast and define in depiction of liver hemangioma as well as higher sensitivity in detection of small lesions. Furthermore this reconstruction method dose not require high performance computer system or long reconstruction time, therefore OSEM is supposed to be good method that can be applied to RBC blood pool SPECT for the diagnosis of liver hemangioma.

Effect of Carrier on Labeling and Biodistribution of Re-188-Hydroxyethylidene diphosphonate (담체가 Re-188-Hydroxyethylidene Diphosphonate의 표지와 생체내분포에 미치는 영향)

  • Chang, Young-Soo;Jeong, Jae-Min;Kim, Bo-Kwang;Cho, Jung-Hyuk;Lee, Dong-Soo;Chung, June-Key;Lee, Seung-Jin;Jin, Ren-Jie;Lee, Sang-Eun;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.4
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    • pp.344-352
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    • 2000
  • Purpose: Re-188-Hydroxyethylidene diphosphonate (HEDP) is a new cost-effective agent for systemic radioisotope therapy of metastatic bone pain. We investigated the influence of carrier for labeling and biodistribution of Re-188-HEDP using HEDP kit with or without carrier ($KReO_4$). Materials and Methods: The kits (HEDP 15 mg, gentisic acid 4 mg and $SnCl_2.2H_2O_2$ 4.5 mg) with or without carrier ($KReO_4$ 0.1 mg) were labeled with Re-188 solution, made available from an in-house generator by boiling for 15 min. We compared the labeling efficiency and stability of carrier-added and carrier-free preparations of Re-188-HEDP Biodistribution and imaging studies of each preparation were performed in ICR mice ($1.85{\sim}3.7MBq/0.1ml$) and SD rats ($74.1{\sim}85.2MBq/0.5ml$). Results: The carrier-added preparation showed high labeling efficiency (95% at pH 5) and high stability in serum (88%, 3 hr). However, the carrier-free preparation showed low labeling efficiency (59% at pH 5) and low stability (43%, 3 hr). The carrier-added preparation showed high uptake in bone and low uptake in stomach and kidneys. However, the carrier-free preparation showed lower uptake in bone and higher uptake in both stomach and kidneys, which is supposed to be due to released perrhenate. The carrier-added preparation also showed better images with higher skeletal accumulation, lower uptake in other organs and lower soft tissue uptake than the carrier-free preparation. Conclusion: The results of these studies clearly demonstrate that addition of carrier perrhenate is required for high labeling efficiency, stability, bone uptake and good image quality of Re-188-HEDP.

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Study on Image Quality Assessment in Whole Body Bone Scan (전신 뼈검사에서의 영상 평가 연구)

  • Kwon, Oh Jun;Hur, Jae;Lee, Han Wool;Kim, Joo Yeon;Park, Min Soo;Roo, Dong Ook;Kang, Chun Goo;Kim, Jae Sam
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.1
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    • pp.30-36
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    • 2015
  • Purpose Whole body bone scan, which makes up a largest percentage of nuclear medicine tests, has high sensitivity and resolution about bone lesion like osteomyelitis, fracture and the early detection of primary cancer. However, any standard for valuation has not yet been created except minimum factor. Therefore, in this study, we will analysis the method which show a quantitative evaluation index in whole body bone scan. Materials and Methods This study is conducted among 30 call patients, who visited the hospital from April to September 2014 with no special point of view about bone lesion, using GE INFINIA equipment. Enumerated data is measured mainly with patient's whole body count and lumbar vertabrae, and the things which include CNR (Contrast to Noise ratio), SNR (Signal to Noise ratio) are calculated according to the mean value signal and standard deviation of each lumbar vertabrae. In addition, the numerical value with the abdominal thickness is compared to each value by the change of scan speed and tissue equivalent material throughout the phantom examination, and compared with 1hours deleyed value. Completely, on the scale of ten, 2 reading doctors and 5 skilled radiologists with 5-years experience analysis the correlation between visual analysis with blind test and quantitative calculation. Results The whole body count and interest region count of patients have no significant correlation with visual analysis value throughout the blind test(P<0.05). There is definite correlation among CNR and SNR. In phantom examination, Value of the change was caused by the thickness of the abdomen and the scan speed. And The poor value of the image in the subject as a delay test patient could be confirmed that the increase tendency. Conclusion Now, a standard for valuation has not been created in whole body bone scan except minimum factor. In this study, we can verify the significant correlation with blind test using CNR and SNR and also assure that the scan speed is a important factor to influence the imagine quality from the value. It is possible to be some limit depending on the physiology function and fluid intake of patient even if we progress the evaluation in same condition include same injection amount, same scan speed and so on. However, that we prove the significant evaluation index by presenting quantitative calculation objectively could be considered academic value.

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Introduction of Kjeldahl Digestion Method for Nitrogen Stable Isotope Analysis (δ15N-NO3 and δ15NNH4) and Case Study for Tracing Nitrogen Source (Kjeldahl 증류법을 활용한 질산성-질소 및 암모니아성-질소 안정동위원소비 분석 및 질소오염원 추적 사례 연구)

  • Kim, Min-Seob;Park, Tae-Jin;Yoon, Suk-Hee;Lim, Bo-La;Shin, Kyung-Hoon;Kwon, Oh-Sang;Lee, Won-Seok
    • Korean Journal of Ecology and Environment
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    • v.48 no.3
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    • pp.147-152
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    • 2015
  • Nitrogen (N) loading from domestic, agricultural and industrial sources can lead to excessive growth of macrophytes or phytoplankton in aquatic environment. Many studies have used nitrogen stable isotope ratios to identify anthropogenic nitrogen in aquatic systems as a useful method for studying nitrogen cycle. In this study to evaluate the precision and accuracy of Kjeldahl processes, two reference materials (IAEA-NO-3, N-1) were analyzed repeatedly. Measured the ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ values of IAEA-NO-3 and IAEA-N-1 were $4.7{\pm}0.2$‰ and $0.4{\pm}0.3$‰, respectively, which are within recommended values of analytical uncertainties. Also, we investigated spatial patterns of ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ in effluent plumes from a waste water treatment plant in Han River, Korea. ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ values are enriched at downstream areas of water treatment plant suggesting that dissolved nitrogen in effluent plumes should be one of the main N sources in those areas. The current study clarifies the reliability of Kjeldahl analytical method and the usefulness of stable isotopic techniques to trace the contamination source of dissolved nitrogen such as nitrate and ammonia.

Microbial Hazard Analysis of Manufacturing Processes for Starch Noodle (당면의 제조공정별 미생물학적 위해요소 분석)

  • Cheon, Jin-Young;Yang, Ji Hye;Kim, Min Jeong;Lee, Su-Mi;Cha, Myeonghwa;Park, Ki-Hwan;Ryu, Kyung
    • Journal of Food Hygiene and Safety
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    • v.27 no.4
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    • pp.420-426
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    • 2012
  • The purpose of this study was to identify control points through microbiological hazard analysis in the manufacturing processes of starch noodles. Samples were collected from the ingredients, manufacturing processes, equipment and environment. Microbiological hazard assessments were performed using aerobic plate counts (APC), Enterobacteriaceae (EB), E. coli and five pathogens including B. cereus, E. coli O157:H7, L. monocytogenes, Salmonella spp., and S. aureus. The APC levels in raw materials were from 2.12 to 3.83 log CFU/g. The contamination levels after kneading were 4.31 log CFU/g for APCs and 2.88 log CFU/g for EB counts. APCs decreased to 1.63 log CFU/g and EB were not detected after gelatinization, but their levels slightly increased upon cooling, cutting, ripening, freezing, thawing, and separating. The reuse of cooling and coating water would be a critical source of microbial increase after cooling. After drying, APCs and EB counts decreased to 5.05 log CFU/g and 2.74 log CFU/g, respectively, and the levels were maintained to final products. These results suggest that the cooling process is a critical control point for microbiological safety, and the cooling water should be treated and controlled to prevent cross contamination by pre-requisite program.

FINITE ELEMENT ANALYSIS OF MAXILLARY CENTRAL INCISORS RESTORED WITH VARIOUS POST-AND-CORE APPLICATIONS (여러가지 post-and-core로 수복된 상악 중절치의 유한요소법적 연구)

  • Seo, Min-Seock;Shon, Won-Jun;Lee, Woo-Cheol;Yoo, Hyun-Mi;Cho, Byeong-Hoon;Baek, Seung-Ho
    • Restorative Dentistry and Endodontics
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    • v.34 no.4
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    • pp.324-332
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    • 2009
  • The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained cortical bone, trabecular bone, periodontal ligament, 4 mm apical root canal filling, and post-and-core. Six combinations of three parallel type post (zirconia ceramic, glass fiber, and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. A 50 N static occlusal load was applied to the palatal surface of the crown with a $60^{\circ}$angle to the long axis of the tooth. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. An increase of the elastic modulus of the post material increased the stress, but shifted the maximum stress location from the dentin surface to the post material. Buccal side of cervical region (junction of core and crown) of the glass fiber post restored tooth was subjected to the highest stress concentration. Maximum von Mises stress in the remaining radicular tooth structure for low elastic modulus resin core (29.21 MPa) was slightly higher than that for high elastic modulus resin core (29.14 MPa) in case of glass fiber post. Maximum displacement of glass fiber post restored tooth was higher than that of zirconia ceramic or stainless steel post restored tooth.

Interrelationships and Path Coefficients of Pericarp Characters in Red Pepper(Capsicum annuum L.) (고추 과육중(果肉重) 구성형질(構成形質)의 상관(相關)과 경로계수분석(經路係數分析))

  • Kim, Yang Choon;Park, Gyu Hwan;Choi, Soon Ho
    • Current Research on Agriculture and Life Sciences
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    • v.2
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    • pp.9-14
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    • 1984
  • This study was performed to obtain the effective selection informations for improvement of quality and increase of yield in red pepper. The eight parents and twenty eight crosses from partial diallel were used as materials for estimation of correlations among the pericarp characters, viz, fruit length, fruit width, pericarp thickness (fresh and dry) and pericarp weight (fresh and dry), between pericarp weight and seed weight and between pericarp weight and the percent of seed weight/pericarp weight and path coefficients on fresh and dry pericarp weight. Results were as follows. In $F_1s$, fresh and dry pericarp weight had positive correlations with fruit length, fruit width, and pericarp thickness. Fresh pericarp weight was also positively correlated with dry pericarp weight. Dry pericarp thickness had a negative correlation with fruit length but had positive correlations with fruit width and fresh pericarp thickness. Fresh pericarp thickness had a positive correlation with fruit width. Significantly positive correlations between $F_1s$ and mid-parents were observed in pericarp characters. Pericarp weight had a positive correlation with seed weight but had a negative correlation with the percent of seed weight/pericarp weight. In path coefficient analysis, it was found that fruit length, fruit width and pericarp thickness had direct effects on fresh and dry pericarp weight and that fruit length had the largest direct effect in $F_1s$.

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A research on the introducing the waterproof corrugated cardboard box for the efficient shipment of chinese cabbages and radishes: Focusing on Garak-dong wholesale market as the center

  • Lee, Rae-Hyup;Sun, Il-Suck
    • Asian Journal of Business Environment
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    • v.2 no.1
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    • pp.25-34
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    • 2012
  • It is possible to use pallet for forwarding as chinese cabbages and radishes are general large-scale trading items at the agricultural wholesale market though, however, most of these are forwarded as it have packed in net bags or in P·E bags. Thus, it is still hard for palletizing. The type of packing the product in the net bag makes it difficult for palletizing. It is not a stable shape enough and easily collapsed for pallet loading. Because of this collapsibility, the corrugated cardboard box is being used to enhance forwarding efficiency, but the existing corrugated cardboard box could be crushed easily by moist what is from the agricultural product's property and it also could be squashed by the mass of the loaded box layers on itself. In contrary, the functional waterproof corrugated cardboard box is not collapsed through palletizing and it is efficient for product management with it's ventilation function in respond to pre-cooling effect. Furthermore, because it has various functional shapes as the open type, the partition type and so on, it is effective for maintaining freshness of the product and standardizing the distribution of agricultural product. It is well-known that it is possible to introduce this box to cargo-works of agricultural product. Consequently, the recognition of main distributors about the pallet distribution of the chinese cabbage and the radish was apprehended in this study for activating mechanization of loading and unloading. The survey was conducted to the main distributors such as the forwarder, the auction dealer and the commission merchant with Garak-dong wholesale market as the center. The appropriate packing materials and problems of the existing method for loading and unloading were derived through the survey. Especially, it was focused on analyzing the difference of recognition between the subject groups for the way of using waterproof cardboard corrugated box to deal with the difficult product for packing in normal corrugated box because of the box's absorption of moist from the agricultural product like a chinese cabbage and a radish. Total In the cases of the forwarders and the commission merchants, the net was highly responded as 45%, 74% from each groups for the best packing material for mechanization of distribution and the waterproof corrugated cardboard box was responded as 20%, 22% from each groups as much preferable than multi-stage wooden box. However, for the radish, the waterproof corrugated cardboard box was the best material as 56%, and the auction trader group supported it for 80%. So, the using the waterproof corrugated cardboard box for mechanization of distribution was negative for the chinese cabbage, but it was positive for the radish. The average was 2.42, the standard deviation was 1.24. The negative response(about 55%) was prevailing more than positive response(about 23%). It could be analyzed that even there was the positive recognition for using the waterproof corrugated cardboard box for the radish though the preference for low price of net bag in the chinese cabbage forwarding procedure. Still now, it seems that is a burden for using the waterproof corrugated cardboard box with high price. In the analysis on the recognition differences about using the waterproof corrugated cardboard box for the chinese cabbages and the radish between the forwarders and the commission merchants, generally the negative recognition was prevailing, but the forwarders(2.696) were more positive for using the waterproof corrugated cardboard box than the commission merchants(2.145).

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Inhibitory Effect of Metal Surface on the Antimicrobial Resistance Microorganism (금속표면이 항생제 내성균주의 생육억제에 미치는 영향)

  • Kim, Jung-Beom;Kim, Jae-Kwang;Kim, Hyunjung;Cho, Eun Jung;Park, Yeon-Joon;Lee, Hae Kyung
    • Annals of Clinical Microbiology
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    • v.21 no.4
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    • pp.80-85
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    • 2018
  • Background: The aim of this study was to comparatively evaluate the bactericidal effects of copper, brass (copper 78%, tin 22%), and stainless steel against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VREFM), and multidrug-resistant Pseudomonas aeruginosa (MRPA). Methods: The isolates (MRSA, VREFM, MRPA) used in this study were mixed wild type 3 strains isolated from patients treated at Uijeongbu St. Mary's Hospital in 2017. These strains showed patterns of multidrug resistance. The lyophilized strains were inoculated into and incubated for 24 hr in tryptic soy broth at $35^{\circ}C$. The initial bacterial inoculum concentration was adjusted to $10^5CFU/mL$. A 100-mL bacterial suspension was incubated in containers made of brass (copper 78%, tin 22%), copper (above 99% purity), and stainless steel at $35^{\circ}C$. Viable counts of bacteria strains were measured for 9 days. Results: In this study, the bactericidal effects of copper and brass on MRSA, VREFM, and MRPA were verified. The bactericidal effect of stainless steel was much weaker than those of copper and brass. The bactericidal effect was stronger on MRPA than on MRSA or VREFM. Conclusion: To prevent cross infection of multidrug resistant bacteria in hospitals, further studies of longer duration are needed for testing of copper materials on objects such as door knobs, faucets, and bed rails.

Selection of Pure Lines with Various Growth and Flowering Characteristics of Spreading Petunia, Petunia × hybrida (생육 및 개화 특성이 다양한 덩굴 페튜니아 순계 선발)

  • Song, Cheon Young
    • FLOWER RESEARCH JOURNAL
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    • v.17 no.2
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    • pp.128-136
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    • 2009
  • To obtain pure lines for breeding $F_1$ varieties of spreading surfinia and wave petunia, Petunia ${\times}$ hybrida, 20 lines of surfinia petunia and 28 lines of wave petunia that were considered uniform in growth and flowering characteristics were selected by self-pollination of the fifth($S_5$) or the seventh generation($S_7$). The 20 selected lines of surfinia petunia had the branch number ranged from 6.0 to 11.0 cm, and the internode length ranged from 2.0 to 4.2 cm. Among them, ten lines, including '$Pe99-017^7$' were above 60 cm of plant width, above 300 leaves in a plant. Fourteen lines including '$Pe99-017^7$' were more than 150 in the number of flower. In the petal color, thirteen lines, including '$Pe99-017^7$', were red-purple; three, including '$Pe99-007^7$', were purple; '$Pe04-086^7$' and '$Pe04-159^7$' were violet; and line '$Pe072-1^7$' was white. Eight lines including '$Pe02-205-2^5$' ranged from 4.0 to 5.0 cm of flowers diameter, and seven lines including '$Pe04-086^5$' ranged from 3.0 to 4.0 cm of leaf length, which is relatively low. Germination rate of the lines was more than 50%. In the wave petunia, the branch number of the 28 selected lines ranged from 8.0 to 13.0 cm, and the internode length ranged from 1.0 to 3.2 cm, which is relatively higher than surfinia petunias. Among them, ten lines, including '$Pe99-020^7$' were above 60 cm of plant width, above 200 leaves in a plant. Twelve lines including '$Pe04-034-2^5$' were more than 150 in the number of flower. In the petal color, eighteen lines, including '$Pe99-020^7$', were red-purple; three, including '$Pe04-113-4^5$', were red; three, including '$Pe04-263^5$', were white; '$Pe04-201^5$' and '$Pe04-263^5$' were violet blue; and line '$Pe04-072-5^5$' was purple. Nine lines including '$Pe04-201^5$' ranged from 4.0 to 5.0 cm of flowers diameter, and eleven lines including '$Pe04-263^5$' ranged from 3.0 to 4.0 cm of leaf length, which is relatively low. All the lines with various growth and flowering characteristics would be very promising to use as breeding materials for $F_1$ hybrids of spreading petunia, Petunia ${\times}$ hybrida.