• Title/Summary/Keyword: BOLD effect

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Chemical Constituents from Leaves of Acanthopanax henryi (II)

  • Li, Zhi;Li, Xiao Jun;Kwon, Ok Kyoung;Wang, Xiang;Zou, Qin Peng;Liu, Xiang Qian;Lee, Hyeong kyu
    • Natural Product Sciences
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    • v.21 no.3
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    • pp.196-204
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    • 2015
  • Nineteen compounds, including one organic acid (1), one anthraquinone (2), one amide (3), and sixteen triterpenoid saponins (4 - 19) were isolated from the leaves of Acanthopanax henryi (Oliv.) Harms (Araliaceae). Their structures were determined on the basis of physicochemical properties and spectral analyses (HR-MS and NMR). Among them, compounds 2, 3, 7, 12 and 19 were new within Araliaceae. Compounds 4, 5, 9 - 11, 13, 14, 16 and 18 were reported for the first time from the Acanthopanax genus. Except for compounds 4 and 9, other compounds were isolated from A. henryi (Oliv.) Harms for the first time. The rare anthraquinone, compound 2, significantly decreased the production of NO and the levels of other inflammatory factors, such as TNF-α and IL-6, in lipopolysaccharide (LPS)-stimulated macrophages in a dose-dependent manner. This is the first time to report anti-inflammatory effect of this compound.

Quantitative Analysis of Susceptibility Effects in TRFGE and CGE Sequences for Functional MRI (뇌기능 영상을 위한 TRFGE와 CGE 기법에서 자화율 효과의 정량적 해석)

  • 정순철;노용만;조장희
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.66-74
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    • 1997
  • fMRI, functional MRI introduced receently appears based on the gradient echo technique which is sensitive to the field inhomogeneity developed due to the local susceptibility changes of blood oxygenation and deoxygenation. There has been many variants of the basic gradient echo sequence which is sensitive to the local inhomogeniety, among others such as GRASS or SSFP to EPISTAR are the most commonly used gradient echo techniques. Common to all these gradient echo techniques is that the signal due to the susceptibility effects is generally decreased with increasing inhomogeneity due to the $T2^{*}$ effect or conventionally konwn as blood oxygenation level dependent(BOLD) effect. It is, also found that the BOLD sensitivity is also dependent on the imaging modes, namely whether the imaging is in axial, or coronal or sagittal mode as well as the directions of the vessels against the main magnetic field. We have, therefore, launched a systematic study of imaging mode dependent signal change or BOLD sensitivity as well as the signal changes due tothe tilting angle of the imaging planes. Study has been made for both TRFGE sequence and CGE sequence to compare the distinctions of the each mode since each technique has different sensitivity againsst susceptibility effect. Method of computation and both the computer simulations and their corresponding experimental results are presented.

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Effect of Clerodendron trichotomum Thunberg tea on anti-hypertension (누리장나무차가 항고혈압에 미치는 영향)

  • Choo, Han-Na;Lee, Soong-In;Kim, Jeong-Sang;Jeong, Jong-Kil
    • The Korea Journal of Herbology
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    • v.30 no.4
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    • pp.129-135
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    • 2015
  • Objectives : Clerodendron trichotomumThunberg grows wild fields and mountains in South Korea and China. They have been used for anti-hypertension disease. This study was performed in order to observe the effects ofClerodendron trichotomumThunberg tea on anti-hypertension.Methods : For the study ofClerodendron trichotomumThunberg tea, we had divided male SHR (Spontaneously Hypertensive Rat) to ten groups. Control group is SHR. The treatment group is SHR which is administered tea extract at dose of 200 mg/kg/day and 500 mg/kg/day orally for 8 weeks. We measured systolic blood pressure, diastolic blood pressure, number of pulse, body weight, total cholesterol and triglyceride from blood serum.Results : The level of systolic and diastolic blood pressure were significantly decreased by 12.5% and 44.9% inClerodendron trichotomumThunberg tea groups than control group. Heart rate ofClerodendron trichotomumThunberg tea groups, 24.5%, was significantly lower than control group. We found that treatment with the water extract fromClerodendron trichotomumThunberg leave and flower significantly decreased weight of body, total cholesterol and triglyceride to 20.4% and 27.7% compared to untreated control group, significantly (P< 0.05).Conclusions : These results suggest that leaf and flower tea ofClerodendron trichotomumThunberg tea is effective in prevention and treatment of hypertension and decreasing cholesterol. Long term consumption ofClerodendron trichotomumThunberg leaf and flower tea can be help in lowering high systolic and blood diastolic pressure, heart rate and blood serum in SHR.

Estimation Method for Brain Activities are Influenced by Blood Pulsation Effect (Blood Pulsation의 효과가 뇌 활성화에 미치는 영향을 알아보는 방법)

  • Lee, W.H.;Ku, J.H.;Lee, H.R.;Han, K.W.;Park, J.S.;Kim, J.J.;Yoon, K.J.;Kim, I.Y.;Kim, S.I.
    • Journal of Biomedical Engineering Research
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    • v.28 no.3
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    • pp.338-343
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    • 2007
  • BOLD T2*-weighted MR images reflects cortical blood flow and oxygenation alterations. fMRI study relies on the detection of localized changes in BOLD signal intensity. Since fMRI measures the very small modulations in BOLD signal intensity that occur during changes in brain activity, it is also very sensitive to small signal intensity variations caused by physiologic noise during the scan. Due to the complexity of movement of various organs associated with heart beat, it is important to reduce cardiac related noise rather than other physiological noise which could be required with relatively simple method. Therefore, a number of methods have been developed for the estimation and reduction of cardiac noise in fMRI study. But, each method has limitation. In this study, we proposed a new estimation method for brain activities influenced by blood pulsation effect using regression analysis with blood pulsation signal and the correspond slice of fMRI. We could find out that the right anterior cingulate cortex and right olfactory cortex and left olfactory cortex were largely influenced by blood pulsation effect for new method. These observed areas are mostly on the structure of anterior cerebral artery in the brain. That is convinced with that our method would be valid and our new method is easier to apply in practice and reduce computational burden than the retrospective method.

Analysis of Susceptibility Effects by Variation of Imaging Modes and Tilting Angles in TRFGE and CGE Sequences for fMRI (뇌기능 영상을 위한 TRFGE, CGE 기법에서 이미징 모드와 기울임 각의 변화에 따른 자화율 효과의 해석)

  • Chung, S.C.;Ro, Y.M.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.571-574
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    • 1997
  • fMRI, functional MRI introduced recently appears based on the gradient echo technique which is sensitive to the field inhomogeneity developed due to the local susceptibility changes of blood oxygenation and deoxygenation. Common to all the gradient echo techniques is that the signal due to the susceptibility effects is generally decreased with increasing inhomogeneity due to the $T2^*$ effect or conventionally known as blood oxygenation level dependent (BOLD) effect. It is, also found that the BOLD sensitivity is also dependent on the imaging modes, namely whether the imaging is in axial, or coronal or sagittal mode as well as the directions of the vessels against the main magnetic field. We have, therefore, launched a systematic study of imaging mode dependent signal change or BOLD sensitivity as well as the signal changes due to the tilting angle of the imaging planes. Study has been made or both TRFGE sequence and CGE sequence to compare the distinctions of the each mode since each technique has different sensitivity against susceptibility effect. Method of computation and both the computer simulations and their corresponding experimental results are presented.

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A comparison of functional MRI and MRSI on occipital cortex by visual stimulation (시각자극에 의한 후두엽 피질에서의 기능적 자기공명영상법과 양성자 대사물질영상의 비교)

  • Kim, T.;Suh, T.S.;Choe, B.Y.;Shinn, K.S.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.291-292
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    • 1998
  • The purpose of the study was aimed to evaluate the BOLD contrast fMRI in occipital lobe and compare this imaging with metabolite changes based on $^1H$ MRS and MRSI before and after visual stimulation. As a result, the activation map were sucessfully produced by thresholding with minimum cross-correlate value of 0.45. In MRS, NAA/Cr ratio is almost same. however, latate was elevated almost 9 times higher than before activation. Lactate metabolic images were consistent with the BOLD effect map. The BOLD contrast fMRI is not enough to detect the activation area in human brain. so, the other modality was required such as lactate metabolic map.

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Comparative Study of Functional Magnetic Resonance Imaging by Global Scaling Analysis (Global Scaling 분석방법에 따른 기능적 자기공명영상의 비교 연구)

  • Yoo, Dong-Soo
    • Investigative Magnetic Resonance Imaging
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    • v.10 no.1
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    • pp.26-31
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    • 2006
  • Purpose : To evaluate the effect of global scaling analysis on brain activation for sensory and motor functional MR imaging study. Materials and methods : Four normal subjects without abnormal neurological history were included. Arm extension-flexion movement was used for motor function and 1KHz pure tone stimulation was used for auditory function. Functional magnetic resonance imaging was performed at 3T MRI (GE, Milwaukee, USA) using BOLD-EPI technique and SPM2 was employed for data analysis. On data analysis, the brain activation images were obtained with and without global scaling by fixing other parameters such as motion correction and realignment. Results : The difference in brain activation between no scaling and global scaling was not large in case of right upper extremity movement (p<0.000001). For auditory test, brain activation with global scaling showed larger activation than that of without global scaling (p<0.05). Conclusion : A caution must be taken into account when analyzing functional imaging data with global scaling especially for functional study of small local BOLD signal change.

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Analysis of the Effect of Local Universities on the Local Economy - Based on the Daranee Analysis -

  • Sung Hyun Park;Ki beom Kim
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.2
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    • pp.73-80
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    • 2023
  • As a result of this study, the income generation effect of local universities on the local economy through the Daranee (1976) model was found to be 110.9 billion won (direct and indirect income 78 billion won, induced income 32.9 billion won). In the case of Korea, it has been verified through a number of previous studies that local universities play a role in preventing the outflow of local talent to the metropolitan area. Considering this, it seems that the government should make bold investments to foster local universities in terms of balanced national development. This is because the movement of local talents to the metropolitan area not only undermines the growth potential of the provinces and undermines the basis for regional existence, but also creates a vicious cycle that hinders balanced national development. To break this vicious cycle, the development of local universities is very important. It is judged that the horizon of balanced national development will be opened when local universities revitalize the local economy through the government's bold investment in local universities and are reborn as entities that provide various services based on the facilities and equipment of local universities.

Subjective Assessments and Analyses of Letter Sizes Under Black and White Contrasts for Various Font Sizes Through the Irradiation-effect (광삼효과를 이용한 흑백 대비에서의 여러 글자크기에 대한 주관적 평가와 분석)

  • Kong, Yong-Ku;Kim, Dae-Min;Sohn, Seong-Tae;Han, Jun-Goo
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.1
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    • pp.107-112
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    • 2010
  • Irradiation is a phenomenon that causes white objects on a black background to appear to spread into near dark backgrounds, but the reverse is not. In this study, the effects of font size and thickness of letters on the legibility were investigated in combinations of black letters/white background as well as white letters/black background. Ten subjects who had been no disease of eyes and their eyesight is over 1.0 were recruited and tested subjective assessments of letter sizes for various font sizes (2pt to 80pt) and thickness of letters (normal, bold) under 600lux illumination and 50cm-distance of eyes and target letters for this study. Ming-style font type which was generally used in text of books, papers, and journals were tested in this study. Results showed that generally people subjectively assessed the white letters on black background (W/B) were larger sizes of letters than the black letters on white background (B/W) even both letter sizes were the same in both normal and bold thickness of letters. This phenomenon was happened in case of only over 22 font size (with border line about 22~24pts). Less than 22 font sizes, many people reported that both letters (W/B and B/W) are looks the same sizes in normal as well as bold letters. These findings were interpreted also by the irradiation phenomenon and more detail information was presented in this manuscript.

Metabolic Changes on Occipital Cortex during Visual Stimulation with Functional MR Imaging and H MR Spectroscopy (기능적 자기공명영상법과 양성자 가지공명분광법을 이용한 시각자극에 의한 후두염 피질의 대사물질 변화)

  • Kim, Tae;Suh, Tae-Suk;Choe, Bo-Young;Kim, Sung-Eun;Lee, Heung-Kyu;Shinn, Kyung-Sub
    • Investigative Magnetic Resonance Imaging
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    • v.3 no.1
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    • pp.47-52
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    • 1999
  • Purpose : The purpose of this study was aimed to evaluate the BOLD(blood oxygen level dependent) contrast fMRI(functional MR imaging) in the occipital lobe and to compare with the metabolic changes based on H MRS (MR spectroscopy) and MRSI (MR spectroscopic imaging) before and after visual stimulation Materials and Methods : Healthy human volunteers (eight males and two females with 24-30 year age) participated in this study. All of the BOLD fMRI were acquired on a 1.5T MR with EPI during supervised visual stimulation in the occipital lobe. The red flicker with 8Hz was used for visual stimulation. After imaging acquisition, the MR images were transferred into unix workstation and processed with acquired from the same location based on the activation map. MRSI (magnetic resonance spectroscopic imaging) was also acquired to analyze the lactate changes before and after stimulation. Results : The activation maps were successfully produced by BOLD effect due to visual stimulation. NAA (N-acetyle aspartate)/Cr (creatine) ratio varied only from $1.79{\pm}0.28{\;}to{\;}1.88{\pm}0.20$ in activation area before and after stimulation. However, the signal intensity of lactate was elevated $9.48{\pm}4.38$ times higher than before activation. Lactate metabolite images were consistent with the activation maps. Conclusion : The BOLD contrast fMRI is enough sensitive to detect the activated area in human brain during the visual stimulation. Lactate metabolite map presents the evidence of lactate elevation on the same area of activation.

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