• Title/Summary/Keyword: $T_2$ contrast

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Development of Adaptive Spatial Filter to Improve Noise Characteristics of PET Images (PET 영상의 잡음개선을 위한 적응적 공간 필터 개발)

  • Woo, S. K.;Choi, Y.;Im, K. C.;Song, T. Y.;Jung, J. H.;Lee, K. H.;Kim, S. E.;Choe, Y. S.;Park, C. C.;Kim, B. T.
    • Journal of Biomedical Engineering Research
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    • v.23 no.3
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    • pp.253-261
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    • 2002
  • A spatially adaptive falter was formulated to imrove PET image qualify and the Performance of the filter was evaluated using simulation and phantom and human PET studies. In the proposed filter. if a pixel was identified as the edge Pixel, the Pixel value was Preserved. Otherwise a Pixel was replaced by the mean of the pixel values weighted by 2:7: 2. A Pixel was identified as the edge Pixel. if it satisfies the following conditions : the number of ADs (absolute difference between center and neighborhood pixels) which is smaller than THl (($pix_max{\times}0.1/log_2(NPM)$, NPM : mean of 6 neighborhood pixels excluding minimum and maximum) is 8-k and the number of ADs which is lager than TH2 ($NPM{\times}0.1$) is k. where k : 2, 3, …, 6. The results of this study demonstrate the superior performance of the Proposed titter compared to Gaussian fitter, weight median filter and subset averaged median filter. The proposed tittering method is simple but effective in increasing uniformity and contrast with minimal degradation of spatial resolution of PET images and thus. is expected to Provide improved diagnositc quality PET images .

A Study on Compensation for Imaging Qualities Having Artifact with the Change of the Center Frequency Adjustment and Transmission Gain Values at 1.5 Tesla MRI (1.5 Tesla 기기에서 중심주파수 조정과 송 신호강도(Transmission Gain)값 변화에 따른 인공물이 있는 자기공명영상의 질 보상에 관한 연구)

  • Lee, Jae-Seung;Goo, Eun-Hoe;Park, Cheol-Soo;Lee, Sun-Yeob;Lee, Han-Joo
    • Progress in Medical Physics
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    • v.20 no.4
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    • pp.244-252
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    • 2009
  • The purpose of this study is to compensate for susceptibility and a ferromagnetic body artifact using CFA and TGV on MR Imaging. A total of 30 patients (15 men and 15 women, mean age: 45 years) were performed on head and neck diseases. MR Unit used a 1.5T superconducting magnet (GE medical system, High Density). This study have investigated by changing with CFA and TGV (70, 90, 110, 130, 150) searching for compensation values about susceptibility and a ferromagnetic body artifact in 60 kg standards of body weight (p<0.05). As a quality results, Image qualities were obtained at different score from CFA and TGV (70, 90, 110, 130, $150=3.23{\pm}0.35$, $4.31{\pm}0.02$ $4.23{\pm}0.21$, $5.12{\pm}0.25$, $7.13{\pm}0.72$, $8.31{\pm}0.01$, $5.21{\pm}0.15$, $6.14{\pm}0.08$, $5.23{\pm}0.72$, $5.91{\pm}0.06$, p<0.05). Absolute CNRs (TG, CNRpre, CNRpost) were acquired with (70:$-1.44{\pm}0.11$, $-2.7{\pm}0.04$, 90:$-2.18{\pm}0.42$, $-4.41{\pm}0.43$, 110:$-2.89{\pm}0.43$, $-5.23{\pm}0.02$, 130:$-2.34{\pm}0.05$, $-5.26{\pm}0.01$, 150: $-2.09{\pm}0.08$, $-3.87{\pm}0.12$, p<0.05). In conclusions, this study could be compensated for metal and flow artifacts surrounding the tissues having artifact by changing CFA and TGV.

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Root Colonization by Beneficial Pseudomonas spp. and Bioassay of Suppression of Fusarium Wilt of Radish (유용 Pseudomonas 종의 근면점유와 무우 Fusarium시들음병의 억제에 관한 생물학적 정량)

  • Lee, Min-Woong
    • The Korean Journal of Mycology
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    • v.25 no.1 s.80
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    • pp.10-19
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    • 1997
  • Fusarium wilt of radish (Raphanus sativus L.) is caused by the Fusarium oxysporum f. sp. raphani (FOR) which mainly attacks Raphanus spp. The pathogen is a soil-borne and forms chlamydospores in infected plant residues in soil. Infected pathogen colonizes the vascular tissue, leading to necrosis of the vascular tissue. Growth promoting beneficial organisms such as Pseudomonas fluorescens WCS374 (strain WCS374), P. putida RE10 (strain RE10) and Pseudomonas sp. EN415 (strain EN415) were used for microorganisms-mediated induction of systemic resistance in radish against Fusarium wilt. In this bioassy, the pathogens and bacteria were treated into soil separately or concurrently, and mixed the bacteria with the different level of combination. Significant suppression of the disease by bacterial treatments was generally observed in pot bioassy. The disease incidence of the control recorded 46.5% in the internal observation and 21.1% in the external observation, respectively. The disease incidence of P. putida RE10 recorded 12.2% in the internal observation and 7.8% in the external observation, respectively. However, the disease incidence of P. fluorescens WCS374 which was proved to be highly suppressive to Fusarium wilt indicated 45.6% in the internal observation and 27.8% in the external observation, respectively. The disease incidence of P. putida RE10 mixed with P. fluorescens WCS374 or Pseudomonas sp. EN415 was in the range of 10.0-22.1%. On the other hand, the disease incidence of P. putida RE10 mixed with Pseudomonas sp. EN415 was in the range of 7.8-20.2%. The colonization by FOR was observed in the range of $2.4-5.1{\times}10^3/g$ on the root surface and $0.7-1.3{\times}10^3/g$ in the soil, but the numbers were not statistically different. As compared with $3.8{\times}10^3/g$ root of the control, the colonization of infested ROR indicated $2.9{\times}10^3/g$ root in separate treatments of P. putida RE10, and less than $3.8{\times}10^3/g$ root of the control. Also, the colonization of FOR recorded $5.1{\times}10^3/g$ root in mixed treatments of 3 bacterial strains such as P. putida RE10, P. fluorescens WCS374 and Pseudomonas sp. EN415. The colonization of FOR in soil was less than that of FOR in root part. Based on soil or root part, the colonization of ROR didn't indicate a significant difference. The colonization of introduced 3 fluorescent pseudomonads was observed in the range of $2.3-4.0{\times}10^7/g$ in the root surface and $0.9-1.8{\times}10^7/g$ in soil, but the bacterial densities were significantly different. When growth promoting organisms were introduced into the soil, the population of Pseudomonas sp. in the root part treated with P. putida RE10 was similar in number to the control and recorded the low numerical value as compared with any other treatments. The population density of Pseudomonas sp. in the treatment of P. putida RE10 indicated significant differences in the root part, but didn't show significant differences in soil. The population densities of infested FOR and introduced bacteria on the root were high in contrast to those of soil. P. putida RE10 and Pseudomonas sp. EN415 used in this experiment appeared to induce the resistance of the host against Fusarium wilt.

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Vegetation Structure of the Hyangjeokbong in the Deogyusan National Park (덕유산국립공원 향적봉 일대 식생구조 연구)

  • Kim, Hyoun-Sook;Lee, Sang-Myong;Song, Ho-Kyung
    • Korean Journal of Environment and Ecology
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    • v.24 no.6
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    • pp.708-722
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    • 2010
  • This study was carried out to classify vegetation structure of the Hyangjeokbong in the Deogyusan National Park using the gradient analysis and phytosociological method. The vegetation was classified into Quercus mongolica community(Rhododendron schlippenbachii subcommunity, typical subcommunity), Q. serrata community, Q. variabillis community, Pinus densiflora community, Cornus controversa community, Fraxinus mandshurica community and Taxus cuspidata community. Ecological characteristics such as species composition, layer structure, vegetation ratio, and the distribution of individual trees by DBH(diameter at breast height) were significantly different among communities. The order of important value of the forest community with DBH 2cm above plants was Q. mongolica(81.2), F. mandshurica, Q. serrata, P. densiflora, Acer pseudosieboldianum, Q. variabillis, Rhododendron schlippenbachii, C. controversa, T. cuspidata. Distribution of DBH of Q. mongolica and Q. serrata had suggesting a continuous domination of these species over the other species for the time being. In contrast, F. mandshurica appeared limited to the valley of the sheet and a higher frequency of young individuals, suggesting a continuous domination of these species the development of a climax forest terrain. P. densiflora and T. cuspidata had suggesting a continuous domination of these species over the other species for the time being in maintain. Q. variabilis and C. controversa had a formality distribution, suggesting a continuous domination of these species over the other species for the time being. This study examined the correlation between each community and the environment according to DCCA ordination. The Q. mongolica community and T. cuspidata community predominated in the highest elevation habitats which had few moisture, Ca and in the low pH. The Q. serrata community mainly occurred in the low elevation habitats which had many moisture. P. densiflora community predominated in the middle elevation and south-facing slope habitats which had few moisture, Ca and in the low pH. F. mandshurica community predominated in the low elevation habitats which had many moisture, Ca and pH.

Discharge Patterns and Peripheral Nerve Inputs to Cardiovascular Neurons in the Medulla of Cats: Comparison between the lateral and medial medulla

  • Kim, Sang-Jeong;Lim, Won-Il;Park, Myoung-Kyu;Lee, Jin;Kim, Jun
    • The Korean Journal of Physiology
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    • v.28 no.2
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    • pp.133-141
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    • 1994
  • The discharge patterns and peripheral nerve inputs to cardiovascular neurons were investigated in rostral ventrolateral medulla (RVLM) and raphe nucleus of cats. The data from the two were compared to determine their roles in cardiovascular regulation and the endogenous analgesic system. Animals were anesthetized with ${\alpha}-chloralose$ and single cell activities were recorded by carbon-filament microelectrode and their relationships with cardiovascular activity were analyzed. In RVLM area, a total of thirty-three cells were identified as cardiovascular neurons. During one cardiac cycle, the mean discharge rate of the neurons was $1.96{\pm}0.29$ and the peak activity was observed 45 ms after the systolic peak of arterial blood pressure. Thirteen cells could be activated antidromically by stimulation of the the $T_2$ intermediolateral nucleus. Forty-three raphe neurons were identified as cardiovascular neurons whose mean discharge rate during one cardiac cycle was $1.02{\pm}0.12$. None of these cells could be activated antidromically. Study of the interval time histogram of RVLM neurons revealed that the time to the first peak was $128{\pm}20.0\;ms$, being shorter than the period of a cardiac cycle. The same parameter found from the raphe neurons was $481{\pm}67.2\;ms$, which was much longer than the cardiac cycle length. Of seventeen RVLM neurons examined ten received only the peripheral $A{\delta}-afferent$ inputs, whereas six RVLM neurons received both $A{\delta}-$ and C-inputs; the remaining one cell received an inhibitory peripheral C-input. In contrast, nine of eleven raphe neurons were found to receive $A{\delta}-inputs$ only. We conclude that the main output of cardiovascular regulatory influences are mediated through the RVLM neurons. The cardiovascular neurons in the raphe nucleus appear to serve as interneurons transferring cardiovascular afferent information to the raphespinal neurons mediating the endogenous analgesic mechanisms.

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Effect of different levels of protein concentrates supplementation on the growth performance, plasma amino acids profile and mTOR cascade genes expression in early-weaned yak calves

  • Peng, Q.H.;Khan, N.A.;Xue, B.;Yan, T.H.;Wang, Z.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.2
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    • pp.218-224
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    • 2018
  • Objective: This study evaluated the effects of different levels of protein concentrate supplementation on the growth performance of yak calves, and correlated the growth rate to changes occurring in the plasma- amino acids, -insulin profile, and signaling activity of mammalian target of rapamycin (mTOR) cascade to characterize the mechanism through which the protein synthesis can be improved in early weaned yaks. Methods: For this study, 48 early (3 months old) weaned yak calves were selected, and assigned into four dietary treatments according to randomized complete block design. The four blocks were balanced for body weight and sex. The yaks were either grazed on natural pasture (control diet) in a single herd or the grazing yaks was supplemented with one of the three protein rich supplements containing low (17%; LP), medium (19%; MP), or high (21%; HP) levels of crude proteins for a period of 30 days. Results: Results showed that the average daily gain of calves increased (0.14 vs 0.23-0.26 kg; p<0.05) with protein concentrates supplementation. The concentration of plasma methionine increased (p<0.05; 8.6 vs $10.1-12.4{\mu}mol/L$), while those of serine and tyrosine did not change (p>0.05) when the grazing calves were supplemented with protein concentrates. Compared to control diet, the insulin level of calves increased (p<0.05; 1.86 vs $2.16-2.54{\mu}IU/mL$) with supplementation of protein concentrates. Addition of protein concentrates up-regulated (p<0.05) expression of mTOR-raptor, mammalian vacuolar protein sorting 34 homolog, the translational regulators eukaryotic translation initiation factor 4E binding protein 1, and S6 kinase 1 genes in both Longissimus dorsi and semitendinosus. In contrast, the expression of sequestosome 1 was down-regulated in the concentrate supplemented calves. Conclusion: Our results show that protein supplementation improves the growth performance of early weaned yak calves, and that plasma methionine and insulin concentrations were the key mediator for gene expression and protein deposition in the muscles.

Effects of Sopoongsangagambang Administration along with External Spray Treatment on Atopic Dermatitis Development in NC/Nga Mice (소풍산가감방(消風散加減方)과 외치방(外治方) 병용이 NC/Nga 아토피 생쥐에 미치는 영향)

  • Min, Young-Gyu;Kim, Jong-Han;Park, Su-Yeon;Choi, Jung-Hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.18 no.1
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    • pp.116-134
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    • 2005
  • Although the parallel prescription of Sopoongsangagambang (SG) administration along with external treatment such as spraying or ointment application on the skin is clinically used for the treatment of atopic dermatitis (AD), molecular mechanism underlying its effectiveness is unknown. Thus in the present study, diverse immune responses in terms of chemical mediators related to AD were investigated using an atopic mouse model NC/Nga after SG administration and external treatment (ET), and major findings are summarized as follows. 1. The clinical severities in 16 and 20 week old NC/Nga mice with SG and ET treatment were decreased to 72.2% and 62.3% respectively compared to the control NC/Nga mice with no drug treatment. 2. IgE, IL-4, IL-5, IL-6, IL-13, IgM, IgG1 and IgG2a levels in the serum of SG and ET treated NC/Nga mouse group were significantly decreased compared to the untreated control mice. In contrast, $IFN-{\gamma}$ showed a significant increase in the experimental group compared to the untreated control group. 3. The spleen weight of SG and ET treated NC/Nga mice was significantly decreased compared to the untreated control group. 4. The B/T ratio in the lymph node of SG and ET treated NC/Nga mice was increased compared to the untreated control group. $CD4^+\;and\;CD8^+$ cell numbers in the lymph node of SG and ET treated NC/Nga mice were significantly increased compared to the untreated control group, but $CD69^+\;and\;CD11a^+$ cells were significantly decreased. 5. mRNA expression levels of IL-4, IL-5, and CCR3 in the skin tissues of SG and ET treated NC/Nga mice were significantly decreased, and expression levels of IL-6, IL-13, $CD69^+/CD3{\varepsilon}^+\;and\;CD19^+/CD44^+$ in the skin tissues of SG and ET treated NC/Mga mice were significantly decreased compared to the untreated control group. $IFN-{\gamma}$ mRNA expression levels were increased compared to the untreated control group. 6. Histological observation of the ear and neck skin tissues showed that the extents of inflammation and infiltrated immune cells in the epidermis and dermis of SG and ET treated NC/Nga mice were highly reduced compared to the untreated control group. 7. Lymphokine assay showed a significant decrease in IL-4 levels in SG and ET treated NC/Nga mice compared to the untreated control group, but the levels of $IFN-{\gamma}$ secretion were significantly increased drug treated NC/Nga mice.

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The Contents of Emergency Treatment Practice Conducted by Emergency Medical Technician and Related Factors (일부 응급구조사들의 응급처치 시행내용과 관련 요인)

  • Jeong, Sang-Gil;Kim, Ki-Soon;Cho, Soo-Hyung;Kang, Myung-Geun;Han, Mi-Ah
    • Journal of agricultural medicine and community health
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    • v.34 no.3
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    • pp.346-358
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    • 2009
  • Objectives: A study was conducted by analysing the contents and frequency of emergency treatment practiced by emergency medical technicians(EMTs) in emergency situations and contains related factors. Methods: The study subjects included 80 EMTs who participated in ongoing education classes during the period from June 25th to June 26th, 2008. the survey included 53 EMTs employed within 119 first aid teams in fire stations in both a metropolitan city and a medium-sized city. From the survey results relation between frequency of emergency treatment and subjects characteristics explored statistically including t-test, X2 test, Pearson correlation and finally stepwise multiple regression. Results: The most frequent procedure by EMTs checking vital signs. The statistically significant related factors overall of the 23 items of emergency treatment frequency was the working area and the grading of EMT certification. In contrast, significant related factors with frequency of IV linkage were found to be the subjects gender, institution employed and the importance of recognizing the item. The statistically significant related factors of that of ECG monitoring was the gender of respondents. Conclusions: To keep the appropriate frequency of emergency treatment by EMT, active efforts to promote their individual importance and confidence cognition are necessary, especially towards males and persons who have 2nd class certification. Moreover, EMTs who work in small cities must be supported.

Hu.4-1BB-Fc fusion protein inhibits allergic inflammation and airway hyperresponsiveness in a murine model of asthma

  • Kim, Byoung-Ju;Kwon, Ji-Won;Seo, Ju-Hee;Choi, Won-Ah;Kim, Young-Jun;Kang, Mi-Jin;Yu, Jin-Ho;Hong, Soo-Jong
    • Clinical and Experimental Pediatrics
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    • v.54 no.9
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    • pp.373-379
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    • 2011
  • Purpose: 4-1BB (CD 137) is a costimulatory molecule expressed on activated T-cells. Repression by 4-1BB is thought to attenuate Th2-mediated allergic reactions. The aim of this study was to investigate the effect of 4-1BB on allergic airway inflammation in a murine asthma model. Methods: BALB/c mice were sensitized to and challenged with ovalbumin (OVA). Hu.4-1BB-Fc was administered 1 day before the first OVA sensitization or 1 day after the second OVA sensitization. Following antigen challenge, airway responsiveness to methacholine was assessed and bronchoalveolar lavage (BAL) fluid was analyzed. Total immunoglobulin (Ig) E, OVA-specific IgE, $IgG_1$, and $IgG_{2a}$ levels in sera were measured by enzyme-linked immunosorbent assay. Lung pathology was also evaluated. Results: In mice treated with Hu.4-1BB-Fc before the first OVA sensitization, there was a marked decrease in airway hyperresponsiveness, total cell count, and eosinophil count in the BAL fluid. In addition, Hu.4-1BB-Fc treatment decreased serum OVA-specific $IgG_1$ levels and increased serum $IgG_{2a}$ level significantly compared with the corresponding levels in mice sensitized to and challenged with OVA. Hu.4-1BB-Fc-treated mice also showed suppressed peribronchial and perivascular inflammatory cell infiltration. In contrast, treatment with Hu.4-1BB-Fc 1 day after sensitization had no effect on airway hyperresponsiveness and showed less suppression of inflammation in lung tissue. Conclusion: Administration of Hu.4-1BB-Fc can attenuate airway inflammation and hyperreactivity in a mouse model of allergic airway inflammation. In addition, administration before sensitization may be more effective. These findings suggest that 4-1BB may be a useful therapeutic molecule against asthma.

Prognostic Significance of CD44v6/v7 in Acute Promyelocytic Leukemia

  • Chen, Ping;Huang, Hui-Fang;Lu, Rong;Wu, Yong;Chen, Yuan-Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.3791-3794
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    • 2012
  • CD44v, especially splice variants containing exon v6, has been shown to be related closely to development of different tumors. High levels of CD44v6/v7 have been reported to be associated with invasiveness and metastasis of many malignancies. The objective of this study was to detect expression of CD44v6-containing variants in patients with acute promyelocytic leukemia (APL) and evaluate the potential of CD44v6/v7 for risk stratification. Reverse transcription polymerase chain reaction (RT-PCR) followed by PCR product purification, ligation into T vectors and positive clone sequencing were used to detect CD44 v6-containing variant isoforms in 23 APL patients. Real-time quantitative PCR of the CD44v6/v7 gene was performed in patients with APL and in NB4 cells that were treated with all-trans retinoic acid (ATRA) or arsenic trioxide ($As_2O_3$). Sequencing results identified four isoforms (CD44v6/v7, CD44v6/v8/v10, CD44v6/v8/v9/v10, and CD44v6/v7/v8/v9/v10) in bone marrow mononuclear cells of 23 patients with APL. The level of CD44v6/v7 in high-risk cases was significantly higher than those with low-risk. Higher levels of CD44v6/v7 were found in three patients with central nervous system relapse than in other patients inthe same risk group. Furthermore, in contrast to ATRA, only $As_2O_3$ could significantly down-regulate CD44v6/v7 expression in NB4 cells. Our data suggest that CD44v6/v7 expression may be a prognostic indicator for APL.