• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2003년도 제27회 추계학술대회
• /
• pp.73-73
• /
• 2003

Purpose: To determine the motor cortex dysfunction in hemiparetic patients due to deep intracerebral hematoma, authors performed proton magnetic resonance spectroscopy (lH MRS) for the evaluation of biochemical changes in the cortex on affected hemisphere according to axonal injury at the level of internal capsule. Methods: Ten control subjects and 14 patients with documentable hemiparesis of varying severity hemiparesis were included. All the hemiparesis was caused by deep intracerebral hematoma (putaminal and thalamic hemorrhage). In vivo 1H MRS study was performed on a 3T MRI/MRS system using STEAM sequence. As a single-voxel technique, Spectral parameters were: 20 ms TE, 2000 ms TR, 128 averages, 2500 Hz spectral width, and 2048 data points. Results: We found that the mean N-acetylaspartate (NAA)/phosphocreatine (Cr) and NAA/choline (Cho) ratios were significantly decreased in the motor cortex of the hemiparesis patients compared with control subjects. Conclusions: 1H MRS examinations of the motor cortex might help to differentiate distinct clinical entities of hemiparesis and to monitor pharmacological effects in therapeutic trials, providing a quantitative biological marker for motor neuron dysfunction. Acknowledgement: This study was supported by a grant of the Center for Functional and Metabolic Imaging Technology, Ministry of Health & Welfare, Republic of Korea. (02-PJ3-PG6-EV07-000).

• Investigative Magnetic Resonance Imaging
• /
• 제21권2호
• /
• pp.102-105
• /
• 2017

In adolescents, sleep deprivation problem is getting worse, and increased caffeine consumption is considered to relieve the stress caused by sleep deprivation and academic burden. In this study, immediate neurologic effects of caffeine intake on adolescents were evaluated in three high school students using the ${\gamma}-aminobutyric$ acid (GABA)/creatine ratio on magnetic resonance spectroscopy (MRS). MEGA-PRESS MRS and TE 135 ms single voxel MRS were performed in the anterior cingulate cortex before and after drinking a cup of coffee, which contained 104 mg of caffeine. GABA and creatine were measured on LCModel 6.3, respectively. In all three students, GABA/creatine ratios were decreased after caffeine intake. The GABA/creatine ratios obtained before caffeine intake were decreased after caffeine intake in all the three adolescents. In this preliminary study, caffeine intake caused an immediate decrease in the GABA/creatine ratio in the brain and it may be related to the neurologic effects of caffeine on an adolescent's brain.

• Journal of Magnetics
• /
• 제19권4호
• /
• pp.345-348
• /
• 2014

Magnetorheological suspensions (MRSs) are smart materials that have the potential to revolutionize several industrial sectors because of their special rheological behaviors. In this paper, MRS, based on carbonyl iron (CI) microparticles that were dispersed in silicone oil with oleic acid, were prepared. We showed that the electroconductibility of MRS was significantly influenced by the intensity of the external magnetic field that was applied. The resistance value can vary from infinite to below $300{\Omega}$ after applying an external magnetic field. The results indicated that this MRS had the property of magnetic-field-tuned insulator to conductor transition. This system has potential applications in controllable MRS electrical devices.

• 한국통신학회논문지
• /
• 제38A권1호
• /
• pp.58-67
• /
• 2013

본 논문에서는 빔포밍 안테나를 탑재한 이동 릴레이(MRS, Mobile Relay Station), 특히 셀 경계 근방에 위치한 이동 릴레이의 링크(link) 의 안정성을 향상시키는 방법에 대해 기술한다. OFDM 통신 방식 기반 시스템의 다중 경로 환경에서의 선형 어레이(Uniform Linear Array)를 이용한 셀 탐색 및 DoA(Direction of Arrival) 추정방법을 제안하였으며, 공간 상관 행렬 기반의 제 1 방법과 이중 차등 상관 행렬 기반의 제 2 방법의 성능을 모의실험을 통하여 평가하였다. 모의실험은 IEEE 802.16e 표준에 기반하였다.

• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2005년도 제30회 춘계학술대회
• /
• pp.93-95
• /
• 2005

자기공명분광법은 극소의 체적내애서 핵자기공명에 의하여 생화학적 성질들을 고유한 주파수에 따라서 대사물질의 신호를 얻는다. 핵자기공명의 신호는 경사자장 혹은 주파수의 크기를 조절하여 체내의 조직성분을 충분히 포함하여 통과시킨다. 획득되어진 원래 데이터는 TE, TR 등의 물리적 상수값의 변화에 의해서 영향을 받는다. 최근의 펄스 시퀀스는 고해상도 3D CSI 및 SVS가 국소적인 체적내의 대사물질의 변화량을 정성적으로 감지하므로 임상데이터로 활용하기 위한 연구가 더욱 절실하다.

• Clinical and Experimental Pediatrics
• /
• 제45권10호
• /
• pp.1292-1298
• /
• 2002

저자들은 반복적인 안면 신경 마비의 과거력을 가진 환아에서 좌측 안면부의 부종과 함께 나타난 Melkersson-Rosenthal 증후군 증례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 대한한방부인과학회지
• /
• 제29권4호
• /
• pp.1-12
• /
• 2016

Objectives: The purpose of this study is to analyze the correlation between the pulse energy and hot flush in women who complain of climacteric syndrome. Methods: We analyzed the values of pulse energy on 78 of perimenopausal and postmenopausal women. The symptoms of patients were assessed by Kupperman’s index (KI) and Menopause Rating Scale (MRS). Statistical analysis was performed by Spearman correlation coefficient and student T-test, using SPSS 18.0 for window program. Results: The results were as follows. 1. There were no statistically significant relation between pulse energy of left Cheok subtracted from left Chon and KI, MRS hot flush score. 2. When divided depending on MRS hot flush score, There were no statistically significant differences on pulse energy. Conclusions: The results suggest that there is no correlation between hot flush score and pulse energy.

• 한국미생물·생명공학회지
• /
• 제16권6호
• /
• pp.463-467
• /
• 1988

L. casei YIT9018에서 자연적으로 발생하는 Lac$^-$ mutant의 발생빈도와 이러한 변이주의 특성을 검토하였다. 보존균주로부터 spontaneous Lac$^-$ mutant의 발생은 MRS 배지에서 0.5%, 10% 환원탈지유에서 0.29%, pure Lac$^+$ colony로부터의 발생은 MRS 배지에서 0.25%, 10% 환원탈지유에서 0.1%의 빈도로 나타났다. 분리된 spontaneous mutant는 대부분이 Lac$^-$ mutant였고 가끔 Lac-Gal-도 나타났다. Lac$^-$ Gal$^+$ mutant는 배양 4일째부터 partial revertant가 출현하였으나 Lac$^-$ Gal$^-$는 전혀 나타나지 않았으며 Lac$^-$ mutant는 wild type보다 우유를 응고시키는데 더 많은 시간을 요하였다.

• 한국자기공명학회논문지
• /
• 제8권1호
• /
• pp.28-36
• /
• 2004

Authors investigated whether there is a lateral effect of $^1$H MRS observable metabolite ratios between the symptomatic and the nonsymptomatic side in the early stage of Parkinson's disease with unilateral symptom. Localized in vivo $^1$H MR spectroscopy (MRS) was used to measure the metabolite levels in the symptomatic and the nonsymptomatic sides of the lentiform nucleus in Parkinson"s disease with unilateral symptom (N=25). The metabolite ratios of NAA/Cr and Cho/Cr in the symptomatic side were compared with those in the nonsymptomatic side. Significant metabolic lateral effect of NAA/(Cho+Cr) ratio was established between the symptomatic and the nonsymptomatic side of lentiform nucleus in Parkinson's disease with unilateral symptom (p<0.05). The ratio of NAA/(Cho+Cr) homolateral to the sympatomatic side of the patient is also lower than that of the control (P<0.05). On the basis of NAA/Cr ratios of lentiform nucleus between the symptomatic and the nonsymptomatic side, the present $^1$H MRS study shows a significant neuronal laterality in Parkinson's disease with unilateral symptom. In vivo $^1$H MRS may provide a diagnostic marker for neuronal dysfunction in Parkinson's disease with unilateral symptom.

• 국제강구조저널
• /
• 제18권4호
• /
• pp.1325-1335
• /
• 2018

This study dealt with investigating the seismic performance of the smart and shape memory alloy (SMA) and magnets plus rubber-spring (MRS) dampers and their effects on the seismic resistance of multiple-span simply supported bridges. The rubber springs in the MRS dampers were pre-compressed. For this aim, a set of experimental works was performed together with developing nonlinear analytical models to investigate dynamic responses of the bridges subjected to earthquakes. Fragility analysis and probabilistic assessment were conducted to assess the seismic performance for the overall bridge system. Fragility curves were then generated for each model and were compared with those of as-built. Results showed dampers could increase the seismic capacity of bridges. Furthermore, from system fragility curves, use of damper models reduced the seismic vulnerability in comparison to the as-built bridge model. Although the SMA damper showed the best seismic performance, the MRS damper was the most appropriate one for the bridge in that the combination of magnetic friction and pre-compressed rubber springs was cheaper than the shape memory alloy, and had the similar capability of the damper.