• Title/Summary/Keyword: transverse relaxation

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Pharmacognostical Studies on Korean Arisaema ringens $S_{CHOTT}$ (한국산 Arisaema ringens $S_{CHOTT}$의 생약학적 연구)

  • Chung, Myung-Hyun
    • Korean Journal of Pharmacognosy
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    • v.2 no.4
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    • pp.163-172
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    • 1971
  • This paper attempts to observe the histological structure of Korean Arisaema ringens $S_{CHOTT}{'s}$ rhizome, to identify it's constituent and to investigate the pharmacological action with it's alcohol extract. The results are : 1) The inner structure of rhizome on the transverse section is divided into external and internal tissues by the ring of intercellular secretary sac. Raphides of calcium oxalate contained in mucilage cell, collateral vascular bundle, are extremely similar to those contained in Pinellia ternata. 2) The organs of the pistillate Arisaema ringens are larger and more plentiful than those of the staminate Arisaema ringens. The sexual identification is easy in the flowering season. 3) The alkaloid is identified by Meyer reagent as white p.p.t. at pH 2 of sulfuric acid. 4) The saponin is indentified remarkably by means of foaming reaction, Lieberman-Burchard reaction and hemolytic reaction. 5) The effect of alcohol extract on the relaxation of the isolated intestine of the rabbit is remarkably shown at the concentration of $10^{-3}g/ml$. 6) The effect of alcohol extract on the isolated ractus muscle of the frog increases the constructive action of acetylcholine at the concentration of $10^{-3}g/ml$. 7) The effect of alcohol extract on the isolated heart movement of the frog is decreased remarkably at the concentration of $10^{-3}g/ml$. 8) The effect of alcohol extract on the blood pressure of the rabbit is decreased by an interavenous injection of $10^{-3}g/kg$.

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The MIN-N family of pure-displacement, triangular, Mindlin plate elements

  • Liu, Y. Jane;Riggs, H.R.
    • Structural Engineering and Mechanics
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    • v.19 no.3
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    • pp.297-320
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    • 2005
  • In recent years the pure displacement formulation for plate elements has not been as popular as other formulations. We revisit the pure displacement formulation for shear-deformable plate elements and propose a family of N-node, displacement-compatible, fully-integrated, pure-displacement, triangular, Mindlin plate elements, MIN-N. The development has been motivated by the relative simplicity of the pure displacement formulation and by the success of the existing 3-node plate element, MIN3. The formulation of MIN3 is generalized to obtain the MIN-N family, which possesses complete, fully compatible kinematic fields, in which the interpolation functions for transverse displacement are one degree higher than those for rotations. General element-level formulas for the thin-limit Kirchhoff constraints are developed. The 6-node, 18 degree-of-freedom element MIN6, with cubic displacement and quadratic rotations, is implemented and tested extensively. Numerical results show that MIN6 exhibits good performance for both static and dynamic analyses in the linear, elastic regime. The results illustrate that the fully-integrated MIN6 element has excellent performance in the thin limit, even for coarse meshes, and that it does not require shear relaxation.

Pattern Extraction of EMG Signal of Spinal Cord Injured Patients via Multiscaled Nonlinear Processing (다중스케일 비선형 처리를 통한 척수 손상 환자의 근전도 신호 패턴 추출)

  • Lee, Y. S.;Lee, J.;Kim, H. D.;Park, I. S.;Ko, H. Y.;Kim, S. H.
    • Journal of Biomedical Engineering Research
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    • v.22 no.3
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    • pp.249-257
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    • 2001
  • The voluntary contracted EMG signal of spinal cord injured patients is very small because the information from central nervous system is not sufficiently transmitted to $\alpha$ motor neuron or muscle fiber. Therefore the acquisited EMG signal from needle or surface electrodes can not be identified obvious voluntary contraction pattern by muscle movement. In this paper we propose the extraction technique of voluntary muscle contraction and relaxation pattern from EMG signal of spinal cord injured patient whose EMG signal is composed of the linear sum of mo색 unit action potentials with two noise sources, additive noise assumed to be white Gaussian noise and high frequency discharge assumed to be not motor unit action potential but impulsive noise. In order to eliminate impulsive noise and additive noise from voluntary contracted EMG signal, we use the FatBear filter which is a nonarithmetic piecewise constant filter, and multiscale nonlinear wavelet denoising processing, respectively. The proposed technique is applied to the EMG signal acquisited from transverse myelitis patients to extract voluntary muscle contraction pattern.

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Geometrically nonlinear thermo-mechanical analysis of graphene-reinforced moving polymer nanoplates

  • Esmaeilzadeh, Mostafa;Golmakani, Mohammad Esmaeil;Kadkhodayan, Mehran;Amoozgar, Mohammadreza;Bodaghi, Mahdi
    • Advances in nano research
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    • v.10 no.2
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    • pp.151-163
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    • 2021
  • The main target of this study is to investigate nonlinear transient responses of moving polymer nano-size plates fortified by means of Graphene Platelets (GPLs) and resting on a Winkler-Pasternak foundation under a transverse pressure force and a temperature variation. Two graphene spreading forms dispersed through the plate thickness are studied, and the Halpin-Tsai micro-mechanics model is used to obtain the effective Young's modulus. Furthermore, the rule of mixture is employed to calculate the effective mass density and Poisson's ratio. In accordance with the first order shear deformation and von Karman theory for nonlinear systems, the kinematic equations are derived, and then nonlocal strain gradient scheme is used to reflect the effects of nonlocal and strain gradient parameters on small-size objects. Afterwards, a combined approach, kinetic dynamic relaxation method accompanied by Newmark technique, is hired for solving the time-varying equation sets, and Fortran program is developed to generate the numerical results. The accuracy of the current model is verified by comparative studies with available results in the literature. Finally, a parametric study is carried out to explore the effects of GPL's weight fractions and dispersion patterns, edge conditions, softening and hardening factors, the temperature change, the velocity of moving nanoplate and elastic foundation stiffness on the dynamic response of the structure. The result illustrates that the effects of nonlocality and strain gradient parameters are more remarkable in the higher magnitudes of the nanoplate speed.

The Ability of Muscle Functional MRI to Detect the Slight Effect of Exercise on Trunk Muscle Activity

  • Tawara, Noriyuki
    • Investigative Magnetic Resonance Imaging
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    • v.26 no.2
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    • pp.117-124
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    • 2022
  • Purpose: In this study, we provide a way to assess even a slight effect of exercise on trunk-muscle activity. Materials and Methods: Seven healthy male participants (mean age, 24.7 ± 3.2 years; height, 171.2 ± 9.8 cm; and weight, 63.8 ± 11.9 kg) performed 15 sets of an exercise with 20 repetitions of 90° hip and right-knee flexion while lying supine. The exercise intensity was measured using the 10-point Rating of Perceived Exertion Scale after the first and 15th sets of exercises. Although cross-sectional areas and functional T2 mapping using ultrafast imaging (fast-acquired muscle functional magnetic resonance imaging, fast-mfMRI) have been proposed for imaging to evaluate exercise-induced muscle activity in real time, no previous studies have reported on the evaluation of trunk-muscle activity using functional T2 mapping. As a method for assessing trunk-muscle activity, we compared functional T2 mapping using ultrafast imaging (fast-mfMRI) with cross-sectional areas. Results: Although the muscle cross-sectional areas were increased by the exercise, there was no significant difference at rest. On the other hand, for all sets, the changes in T2 were significant compared with those at rest (P < 0.01). These results demonstrate that T2, calculated from fast-mfMRI images can be used to detect even a small amount of muscle activity induced by acute exercise, which was impossible to do with cross-sectional areas. Conclusion: Fast-mfMRI, which can also display functional information with detailed forms, enabled non-invasive real-time imaging for identifying and evaluating the degree of deep trunk-muscle activity induced by exercise.

A Preliminary Study of the Effect of Kegel Exercise Using a Pressure Biofeedback Unit on Maximum Voluntary Ventilation and Abdominal Muscle Thickness (압력 생체되먹임 기구를 이용한 케겔 운동이 최대 수의적 환기량과 배 근육 두께에 미치는 사전 연구)

  • Lee, Kyung-Soon;Park, Kang-Hui;Park, Han-Kyu
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.1
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    • pp.81-89
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    • 2022
  • Purpose : Kegel exercises reported that it is effective in managing stress-related or complex urinary incontinence through contraction and relaxation of the pelvic floor muscles. In many previous studies, it was confirmed that Kegel exercise is involved in respiration as well as urinary system diseases. However, there is a lack of research on the effect of pelvic setting when performing Kegel exercises. Therefore, this study was conducted to investigate the effect on maximum voluntary ventilation (MVV) and abdominal muscle thickness through Kegel exercise after lumbar-pelvic motor control using pressure biofeedback unit (PBU). Methods : The subjects of this study were 10 healthy female students in their 20s. Subjects measured MVV with a spirometer. In hooklying, external oblique, internal oblique, and transverse abdominis of the dominant hand were measured using ultrasound. The measured value was an average of three times. After one week of intervention, measurements were made in the same manner. Before Kegel exercise, pelvic setting training was performed using PBU. In hooklying, PBU was placed in the waist and set to 40 mmHg, and it was adjusted to 60 mmHg through pelvic muscle contraction. For Kegel exercise, the pelvis was first set using PBU, and then the pelvic floor muscles were contracted for 8 seconds and relaxed for 8 seconds, 10 times, 1 set, and 3 sets. Results : In MVV, a significant difference was confirmed after exercise than before exercise (p<.05). There was also a significant difference in abdominal muscle thickness before and after exercise (p<.05). Conclusion : Based on the results of this study, Kegel exercise using PBU had an effect on MVV and abdominal muscle thickness. However, since this study was conducted without a control group as a preliminary study, additional research should be conducted to supplement this.

Quantitative Evaluation of Liver Fibrosis on T1 Relaxometry in Comparison with Fibroscan (Fibroscan과 비교를 통한 T1 MR Relaxometry를 이용한 간섬유화의 정량적 평가)

  • Byeong Hak Sim;Suk Hee Heo;Sang Soo Shin;Seong Beom Cho;Yong Yeon Jeong
    • Journal of the Korean Society of Radiology
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    • v.81 no.2
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    • pp.365-378
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    • 2020
  • Purpose This study was performed to determine whether the T1 relaxation time of gadoxetic acid-enhanced liver MR imaging is useful for detecting and staging liver fibrosis in patients with chronic liver disease. Materials and Methods One hundred and three patients with suspected focal liver lesion underwent MR imaging and Fibroscan. Fibroscan was chosen as the reference standard for classifying liver fibrosis. T1 relaxation times were acquired before (preT1), 20 minutes after (postT1) contrast administration, and reduction rate of T1 relaxation time (rrT1) on transverse 3D VIBE (volumetric interpolated breath-hold examination) sequence using 3T MR imaging. The optimal cut-off values for the fibrosis staging were determined with ROC analysis. Results PreT1 and postT1 increased and rrT1 decreased constantly with increasing severity of liver fibrosis according to the METAVIR score (F0-F4). There were statistically significant differences between F2 and F3 in preT1 (F2, 836.0 ± 74.7 ms; F3, 888.6 ± 77.5 ms, p < 0.05) and between F3 and F4 in postT1 (F3, 309.0 ± 80.2 ms; F4, 406.6 ± 147.7 ms, p < 0.05) and rrT1 (F3, 65.4 ± 7.7%; F4, 57.3 ± 11.4%, p < 0.05). ROC analysis revealed that combination test (preT1 + postT1) was the best test for predicting liver fibrosis. Conclusion PreT1 and postT1 increased constantly with increasing severity of liver fibrosis. T1 mapping in gadoxetic acid-enhanced liver MR imaging could be a helpful complementary sequence to determine the liver fibrosis stage.

Effect of Kegel Exercise Using Pressure Biofeedback Unit for 2 Weeks on Maximum Voluntary Ventilation and Abdominal Muscle Thickness (2주간 압력 생체되먹임 기구를 이용한 케겔 운동이 최대 자발적 환기량과 배 근육 두께에 미치는 영향)

  • Park, Han-Kyu;Lee, Jung-Hee;Kim, Cho-Hee;Yoon, Ju-Mi;Jo, Ye-Eun;Lee, So-Hee
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.4
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    • pp.175-185
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    • 2022
  • Purpose : This study was conducted to determine the effect of Kegel exercise using a pressure biofeedback unit (PBU) for 2 weeks on maximum voluntary ventilation (MVV) and abdominal muscle thickness based on previous studies. Methods : The subjects of this study were 20 healthy female students in their 20s. Subjects were randomly assigned to two groups. Eleven subjects were assigned to the experimental group (EG) and 9 subjects were assigned to the control group (CG). Subjects measured MVV with a spirometer. In hooklying position, transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) of the dominant side were measured using ultrasound. For the measurement value, the average value of three times was adopted. After 2 weeks of intervention, the measurements were measured in the same way. In the EG, pelvic setting training using PBU was performed before Kegel exercise. The PBU was first placed at the waist in the Kegel exercise position and the starting pressure was set at 40 mmHg and adjusted to 60 mmHg through pelvic floor muscle contraction. After performing pelvic control using PBU, Kegel exercise was performed with 8 seconds of contraction, 8 seconds of relaxation, and 3 sets of 10 reps per set. A significance level of 𝛼=.05 was used to verify statistical significance. Results : In the variable of MVV, a significant increase was confirmed in the EG (p<.05). In the abdominal muscle thickness variable, significant increases were confirmed in IO and TrA in the EG (p<.05). In addition, a significant increase in IO was confirmed in the CG (p<.05). Significant increases in IO and TrA were confirmed between groups (p<.05). Conclusion : Based on the previous study, this study confirmed that Kegel exercise using a PBU had a positive effect on MVV and abdominal muscle thickness based on a 2-week intervention.

Effects of Pelvic Floor Muscle Exercise According to Support Surface on Maximum Inspiratory Pressure and Maximum Expiratory Pressure and Abdominal Muscle Thickness in Female College Students in Their 20s (지지면에 따른 골반 바닥 근육 운동이 20대 여대생들의 최대 들숨 압력, 최대 날숨 압력 그리고 배 근육 두께에 미치는 영향)

  • Han-Kyu Park;Yun-Hui Kim;Si-Yun Lee;Jeong-In Lee;Su-Jin Oh;Ji-Young Hwang
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.51-60
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    • 2023
  • Purpose : The purpose of this study was to determine the effect of pelvic floor muscle exercise (PFME) on an unstable support surface on maximal inspiratory pressure (MIP), maximum expiratory pressure (MEP), and abdominal muscle thickness as a method for effective PFME. Methods : This study was performed on 22 subjects. They were matched and divided into two groups based on body mass index; the experimental group (EG) performed PFME on a foam roller (n= 11), the control group (CG) performed PFME on a stable support surface (n= 11). Kegel exercise was performed with 10 seconds of contraction, 10 seconds of relaxation, and 4 sets of 10 reps per set. Both of group executed the exercise 3 times a week for 2 weeks. MIP and MEP was measured using a spirometer. Abdominal muscle thickness was measured using ultrasound. The paired t-test was used to compare difference on each group and the comparison between groups was analyzed using the independent t-test. A significance level of α= .05 was used to verify statistical significance. Results : The EG showed a significant increase in the MEP (p<.05). The CG showed a significant increase in the MEP (p<.05). There was no significant difference in the two groups (p>.05). The EG showed a significant increase in the external oblique, internal oblique and transverse abdominis (p<.05). The CG showed a significant increase in the internal oblique (p<.05). There was no significant difference in the two groups (p>.05). Conclusion : Based on the results of this study, additional research should be conducted to correct the limitations of this study to confirm that PFME performed on a foam roller has a positive effect on respiratory muscle strength and abdominal muscle thickness.

Evaluation of Renal Pathophysiological Processes Induced by an Iodinated Contrast Agent in a Diabetic Rabbit Model Using Intravoxel Incoherent Motion and Blood Oxygenation Level-Dependent Magnetic Resonance Imaging

  • Yongfang Wang;Xin Zhang;Bin Wang;Yang Xie;Yi Wang;Xuan Jiang;Rongjia Wang;Ke Ren
    • Korean Journal of Radiology
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    • v.20 no.5
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    • pp.830-843
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    • 2019
  • Objective: To examine the potential of intravoxel incoherent motion (IVIM) and blood oxygen level-dependent (BOLD) magnetic resonance imaging for detecting renal changes after iodinated contrast-induced acute kidney injury (CI-AKI) development in a diabetic rabbit model. Materials and Methods: Sixty-two rabbits were randomized into 2 groups: diabetic rabbits with the contrast agent (DCA) and healthy rabbits with the contrast agent (NCA). In each group, 6 rabbits underwent IVIM and BOLD imaging at 1 hour, 1 day, 2 days, 3 days, and 4 days after an iohexol injection while 5 rabbits were selected to undergo blood and histological examinations at these specific time points. Iohexol was administrated at a dose of 2.5 g I/kg of body weight. Further, the apparent transverse relaxation rate (R2*), average pure molecular diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f) were calculated. Results: The D and f values of the renal cortex (CO) and outer medulla (OM) were significantly decreased compared to baseline values in the 2 groups 1 day after the iohexol injection (p < 0.05). A marked reduction in the D* values for both the CO and OM was also observed after 1 hour in each group (p < 0.05). In the OM, a persistent elevation of the R2* was detected for 4 days in the DCA group (p < 0.05). Histopathological changes were prominent, and the pathological features of CI-AKI aggravated in the DCA group until day 4. The D, f, and R2* values significantly correlated with the histological damage scores, hypoxia-inducible transcription factor-1α expression scores, and serum creatinine levels. Conclusion: A combination of IVIM and BOLD imaging may serve as a noninvasive method for detecting and monitoring CI-AKI in the early stages in the diabetic kidney.