• Title/Summary/Keyword: Pulse Control

Search Result 2,246, Processing Time 0.028 seconds

High-Resolution MRI Study on Mouse Brain Using Micro-Imaging (초고해상도 미세영상 기법을 이용한 Mouse 뇌의 자기공명영상 연구)

  • Han, Doug-Young;Yoon, Moon-Hyun;Choe, Bo-Young
    • Investigative Magnetic Resonance Imaging
    • /
    • v.12 no.2
    • /
    • pp.142-147
    • /
    • 2008
  • Purpose : By using the micro-imaging unit modified from NMR spectrometer, the high resolution MRI protocols of finer than 100 micron in 5 minutes, is sought for mouse, which plays a central role in animal studies Materials and Methods : C57BL/6 mouse, lighter than 50 gram, is used for the experiments. The superconducting magnet is vertical type with 89 mm inner diameter at 4.9 Tesla. The diameter of rf-coil is 30 mm. Mostly used techniques are the fast spin echo and the gradient echo pulse sequence. Results : For 2D images, proton density and T2 weighted images are obtained and their optimum experimental variables were sought. Minute structure of mouse brain can be recognized and 3D brain image is also obtained additionally. 3D image will be useful particularly for the dynamic contrast study using various contrast agents. Conclusion : Like the case of human and other small animals, the high resolution of mouse brain is enough to recognize the minute structure of it. Recently, similar studies are reported domestically, but it seems only a beginning stage. Due to easiness of breeding/control, mouse MRI study will soon play a vital part in brain study.

  • PDF

Autocrine Regulation of Gonadotropin-releasing Hormone (GnRH) Operates at Multiple Control levels of GnRH Gene Expression in GT1-1 Neuronal Cells

  • Jin Han;Sehyung Cho;Woong Sun;Kyungjin Kim
    • Animal cells and systems
    • /
    • v.2 no.4
    • /
    • pp.483-488
    • /
    • 1998
  • We previously found that a potent gonadotropin-releasing hormone (GnRH) agonist, buserelin, decreases GnRH promoter activity together with GnRH mRNA level, providing evidence for an autoregulatory mechanism operating at the level of GnRH gene transcription in immortalized GT1-1 neuronal cells. To examine whether agonist-induced decrease in GnRH mRNA level requires the continuous presence of buserelin, we performed a pulse-chase experiment of buserelin treatment. Short-term exposure (15 min) of GT1-1 neuronal cells to buserelin ($10{\mu}M$) was able to decrease GnRH mRNA levels when determined 24 h later. When GT1-1 cells were treated with buserelin ( $10{\mu}M$) for 30 min and then incubated for 1, 3, 6, 12, 24, and 48 h after buserelin removal, a significant decrease in GnRH mRNA levels was observed after the 12 h incubation period. These data indicate that inhibitory signaling upon buserelin treatment may occur rapidly, but requires a long time (at least 12 h) to significantly decrease the GnRH mRNA level. To examine the possible involvement of de novo synthesis and/or mRNA stability in buserelin-induced decrease in GnRH gene expression, actinomycin D ($5{\mu}m/ml$), a potent RNA synthesis blocker, was co-treated with buserelin. Actinomycin D alone failed to alter basal GnRH mRNA Revel, but blocked the buserelin-induced decrease in GnRH mRNA level at 12 h of post-treatment. These data suggest that buserelin may exert its inhibitory action by altering the stability of GnRH mRNA. Moreover, a polvsomal RNA separation by sucrose gradient centrifugation demonstrated that buserelin decreased the translational efficiency of the transcribed GnRH mRNA. Taken together, these results clearly indicate that GnRH agonist buserelin acts as an inhibitory signal at multiple levels such as transcription mRNA stability, and translation.

  • PDF

Effect of Banhahoobak-tang (Banxiahoupo-tang) Extract (BHTe) on Psychological Stress (반하후박탕(半夏厚朴湯)이 생쥐의 심리적 스트레스에 미치는 영향과 유전자 분석)

  • Choi, Geum-Ae;Cho, Su-In;Kim, Kyeong-Su;Choi, Chang-Won;Wei, Tung-Shuen;Yang, Seung-Joung;Park, Soo-Yeon;Kim, Kyeong-Ok
    • Journal of Oriental Neuropsychiatry
    • /
    • v.26 no.2
    • /
    • pp.117-130
    • /
    • 2015
  • Objectives: Banhahoobak-tang has been used to treat plum-pit qi, chest and hypochondriac distension, moist or greasy tongue coat, and wiry slow or wiry slippery pulse. It might be used to control coughing and vomiting. We observed that Banhahoobak-tang extract (BHTe) had anti-psychological stress effect. The objective of this study was to determine the effect of BHTe on restoring the transcriptional regulation of genes related to psychological stress. Methods: After giving psychological stress to mice, BHTe was orally administered at 100 mg/kg/day for five days. After extracting whole brain tissue from the mice, the gene expression changes were determined by microarray. Transcription factor binding site (TFBS) analysis showed up- and down-regulated genes related to psychological stress were protected by BHTe and segregated according to the structure of TFBS. We performed text based Pubmed search to select significant target genes involved in psychological stress affected by BHTe. Results: 1. Serum corticosterone level was decreased in the BHTe administered group, although the psychological stress was increased. 2. The BHTe administered group had no significant change in noradrenaline content in brain tissue, but the psychological stress group had decreased level. 3. The BHTe administered group had increased time of staying at open-arm than the psychological stress group. 4. Microarray revealed that TANK and RARA genes were up-regulated genes while AES, CDC42, FOS, NCL, and PVR were down-regulated genes by psychological stress but restored by BHTe.

Development of 3D Radiation Position Identification System of Multiple Radiation Sources using Plastic Scintillator and NaI(TI) Detector (플라스틱 Scintillator와 NaI(TI) 검출기를 이용한 다수의 방사선원 위치를 3차원으로 판별하는 측정시스템 개발)

  • Kwak, Dong-Hoon;Ko, Tae-Young;Lee, Seung-Ho
    • Journal of IKEEE
    • /
    • v.22 no.3
    • /
    • pp.638-644
    • /
    • 2018
  • In this paper, we develop a measurement system that uses 3D Scintillator and NaI(TI) Detector to 3-dimensionally identify the location of multiple radiation sources in moving vehicle loads. The radiation measurement system consists of radiation measurement (plastic scintillator), 2-channel Pulse Counter Board, nuclide analysis (NaI(TI) detector) and 1 channel MCA Board. The source locator algorithm calculates the coordinate value of the ratio of the CPS value($1/r^2$) of the source according to the angle(${\theta}$) in inverse proportion to the square of the distance(X, Y) through the SVM classification. The coordinate values are input every predetermined period of the spectrum, and after analyzing the spectrum per unit cycle, the position of the nuclide at the time is calculated by determining whether or not the nuclide is present in the remaining part except for the background area. As a result of the position discrimination test, the error within the international standard of ${\pm}1m$ was shown. Thus, the utility of the proposed system has been demonstrated.

Neuroprotective Effects of Sacral Epidural Neuromodulation Following Spinal Cord Injury : An Experimental Study in Rats

  • Lee, Chang-Hyun;Hyun, Seung-Jae;Yoon, Cheol-Yong;Lim, Jae-Young;Jahng, Tae-Ahn;Kim, Ki-Jeong
    • Journal of Korean Neurosurgical Society
    • /
    • v.52 no.6
    • /
    • pp.509-512
    • /
    • 2012
  • Objective : The purpose of this study is to evaluate neuroprotective effect of sacral neuromodulation in rat spinal cord injury (SCI) model in the histological and functional aspects. Methods : Twenty-one female Sprague Dawley rats were randomly divided into 3 groups : the normal control group (CTL, n=7), the SCI with sham stimulation group (SCI, n=7), and the SCI with electrical stimulation (SCI+ES, n=7). Spinal cord was injured by dropping an impactor from 25 mm height. Sacral nerve electrical stimulation was performed by the following protocol : pulse duration, 0.1 ms; frequency, 20 Hz; stimulation time, 30 minutes; and stimulation duration, 4 weeks. Both locomotor function and histological examination were evaluated as scheduled. Results : The number of anterior horn cell was $12.3{\pm}5.7$ cells/high power field (HPF) in the CTL group, $7.8{\pm}4.9$ cells/HPF in the SCI group, and $6.9{\pm}5.5$ cells/HPF in the SCI+ES group, respectively. Both the SCI and the SCI+ES groups showed severe loss of anterior horn cells and myelin fibers compared with the CTL group. Cavitation and demyelinization of the nerve fibers has no significant difference between the SCI group and the SCI+ES group. Cavitation of dorsal column was more evident in only two rats of SCI group than the SCI+ES group. The locomotor function of all rats improved over time but there was no significant difference at any point in time between the SCI and the SCI+ES group. Conclusion : In a rat thoracic spinal cord contusion model, we observed that sacral neuromodulation did not prevent SCI-induced myelin loss and apoptosis.

Neuronal Dysfunction in Patients with Chronic Alcoholism Evaluated by In Vivo $^1H$ Magnetic Resonance Spectroscopy (알콜중독환자의 신경기능 장애: 생체 양성자 자기공명분광 연구)

  • Bo-Young Choe;Euy-Neyng Kim;Chang-Wook Lee;In-Ho Baik;Kwang-Soo Lee;Byung-Chul Son;Heung-Jae Chun;Hyoung-Koo Lee;Tae-Suk Suh
    • Investigative Magnetic Resonance Imaging
    • /
    • v.4 no.2
    • /
    • pp.94-99
    • /
    • 2000
  • Purpose : With the use of localized, water-suppressed in vivo $^1H$ magnetic resonance spectroscopy (MRS), we evaluated the proton metabolic alterations in patients with chronic alcoholism and healthy normal controls. Material and Methods : Patients with chronic alcoholism (N = 10) and normal control subjects (N = 10) underwent MRS examinations using a stimulated echo acquisition mode (STEAM) pulse sequence with $2{\times}2{\times}2{\;}\textrm{cm}^3$ volume of interest (VOI) in the left cerebellum and basal ganglia. Proton metabolite ratios relative to creative (Cr) were obtained using a Marquart algorithm. Results : The specific feature in patients with chronic alcoholism was a significant decrease of N-acetylaspartate (NAA)/Cr ratio in the left cerebellum, compared with normal controls. No clear correlation of other metabolite ratios such as choline (Cho)/Cr and inositols (Ins)/Cr was established. Conclusion : Our preliminary study suggests that the reduction of NAA/Cr ratio may indicate neuronal loss in patients with chronic alcoholism. Thus, in vivo 1H MRS may be a useful modality in the clinical evaluation of patients with chronic alcoholism based on the proton metabolite ratios.

  • PDF

New Ruthenium Complexes for Semiconductor Device Using Atomic Layer Deposition

  • Jung, Eun Ae;Han, Jeong Hwan;Park, Bo Keun;Jeon, Dong Ju;Kim, Chang Gyoun;Chung, Taek-Mo
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2014.02a
    • /
    • pp.363-363
    • /
    • 2014
  • Ruthenium (Ru) has attractive material properties due to its promising characteristics such as a low resistivity ($7.1{\mu}{\Omega}{\cdot}cm$ in the bulk), a high work function of 4.7 eV, and feasibility for the dry etch process. These properties make Ru films appropriate for various applications in the state-of-art semiconductor device technologies. Thus, it has been widely investigated as an electrode for capacitor in the dynamic random access memory (DRAM), a metal gate for metal-oxide semiconductor field effect transistor (MOSFET), and a seed layer for Cu metallization. Due to the continuous shrinkage of microelectronic devices, better deposition processes for Ru thin films are critically required with excellent step coverages in high aspect ratio (AR) structures. In these respects, atomic layer deposition (ALD) is a viable solution for preparing Ru thin films because it enables atomic-scale control of the film thickness with excellent conformality. A recent investigation reported that the nucleation of ALD-Ru film was enhanced considerably by using a zero-valent metallorganic precursor, compared to the utilization of precursors with higher metal valences. In this study, we will present our research results on the synthesis and characterization of novel ruthenium complexes. The ruthenium compounds were easy synthesized by the reaction of ruthenium halide with appropriate organic ligands in protic solvent, and characterized by NMR, elemental analysis and thermogravimetric analysis. The molecular structures of the complexes were studied by single crystal diffraction. ALD of Ru film was demonstrated using the new Ru metallorganic precursor and O2 as the Ru source and reactant, respectively, at the deposition temperatures of $300-350^{\circ}C$. Self-limited reaction behavior was observed as increasing Ru precursor and O2 pulse time, suggesting that newly developed Ru precursor is applicable for ALD process. Detailed discussions on the chemical and structural properties of Ru thin films as well as its growth behavior using new Ru precursor will be also presented.

  • PDF

Corticosteroids Add-on Therapy in the Acute Phase of Kawasaki Disease (고위험군 가와사끼병에서 스테로이드 추가 요법의 효과)

  • Kang, Seon-Mi;Moon, Eun-Kyung;In, Su-Mi;Kil, Hong-Ryang
    • Clinical and Experimental Pediatrics
    • /
    • v.45 no.12
    • /
    • pp.1571-1576
    • /
    • 2002
  • Purpose : Recently, clinical trials of steroid add-on therapy were reported with variable results in Kawasaki disease. We analyzed the clinical outcomes of patients at high risk of with Kawasaki disease(${\geq}4$ points of Harada score) treated by three commonly used different treatment regimens, with or without corticosteroids. Methods : Medical records of 96 children with Kawasaki disease treated with one of the threee regimens were reviewed retrospectively. Regimen 1 was aspirin(100 mg/kg/day) plus intravenous gamma globulin 2 g/kg single dose; regimen 2, aspirin(100 mg/kg/day) plus intravenous gamma globulin 1 g/kg single dose; regimen 3, regimen 2 plus prednisolone(2 mg/kg/day), followed by tapering two weeks and pulse therapy of methyl prednisolone performed in cases of retreatment. Also low dose aspirin was given in all three regimens for eight weeks after the acute phase. The cardiovascular and laboratory evaluations were performed on acute phase, immediate after acute phase, and subacute phase, eight weeks after treatment. Results : The frequency of coronary artery lesions and laboratory findings in the three different regimens were similar. The more rapid control of fever after treatment was noted in regimen 3. Furthermore the frequency of retreatment was decreased in regimen 3 compared to the other two regimens. Conclusion : Steroid add-on therapy showed some beneficial outcome compared to conventional treatment regimens. The role of steroid in the treatment of Kawasaki disease should be reassessed in systemic manner.

흉총창에 의한 심방파열 치험 2례

  • Lee, Doo-Yun;Kwack, Sang-Ryong
    • Journal of Chest Surgery
    • /
    • v.13 no.1
    • /
    • pp.60-65
    • /
    • 1980
  • We have experienced 2 cases of the hunshot wound sof the chest involving cardiac injuries at department of the thoracic surgery, Capital Armed Forces General Hospital during I year from April I 1979 to Jan. 1980. In one case of two patients , he was a 22 years old man who was transported to this emergency room 4 hour 10 minutes after having gunshot wound of the left chest by helicopter. Physical examination showed small inlet in left 3rd ICS and left parasternal border, large outlet in left 8th ICS and left scapular line, no breath sound on left side and distant heart sound. chest roentgenography demonstrated marked pleural effusion in left side and mediastinum shifted to right. As soon as chest X-ray was taken, the bleeding through penetrating wound became profuse and cardiac arrest ensued. Closed chest cardiac massage was started and vigorous transfusion continued, but no effective cardiac activity could not be obtained. The patient was pronounced dead due to exsanguinating hemorrhage from wuwpected cardiac wounds. In this critically injured patient with evidence of intrathoracic hemorrhage and suspected cardiac penetration, only emergency thoracic exploration and immediate surgical control of bleeding points might offer the maximum possibility of survival. The other case was a 23 years old man who was transferred to the emergency room 4 hours 50 minutes after having kmultiple communicated fractures of sternum and linear fracture of right mandible by a missile. Examination revealed about 30% skin loss of the anterior chest wall, weak pulse of 96 beats/min., distant heart sound and decreased breath sounds bilaterally. finding on the chest X-ray films showed multiple sternal fractures, marked pericardial effusion indicating hemopericardium. So, the patient was moved immediately to the operation room where, after endotracheal tube inserted, a median sternotomy was performced. A hemorrhagic congestion of the right upper lobe and marked bulging pericardium were disclosed. The pericardium was opened anterior to right phrenic nerve and exsanguinating hemorrhage ensued from the 0.5cm lacerated wound in the auricle of right atrium. The rupture site of right atrium was occluded with non-crushing vascular clamps and then was over sewn with interrupted sutures. It was thought to be highly possible that he was alive long enough to have cardiorrhaphy because of cardiac tamponade, which prevented exsanguinating hemorrhage. He was taken closed reduction for linear fracture of right mandible 2 weeks after repair of ruptured right auricle in dental clinic. This patient's post-operative course was not eventful.

  • PDF

Comparison of the Floodplain Vegetation Structure According to Existence of Lateral Connectivity in Streams (하천의 횡적 연결성 유무에 따른 홍수터 식생 구조의 비교)

  • Chu, Yunsoo;Jin, Seung-Nam;Cho, Hyunsuk;Cho, Kang-Hyun
    • Journal of Wetlands Research
    • /
    • v.19 no.3
    • /
    • pp.327-334
    • /
    • 2017
  • The flood pulse in streams enhances the biodiversity and ecosystem services of the channel-floodplain ecosystems by exchanging water, nutrients, sediments and organisms. However, the lateral connectivity in most streams of Korea has been disrupted by the levee constructions for the purpose of flood control and land use of floodplains. To compare the characteristics of floodplain vegetation according to existence of lateral connectivity in streams, we investigated the geomorphological and soil environmental factors and structures and distribution of vegetation in the floodplains connected and isolated by levee to the channel in Cheongmi Stream, Seom River, Hwangguji Stream, Mangyeong River, Gomakwon Stream, and Boseong River, Korea. In comparison of soil environments, moisture and clay contents were higher in the isolated floodplain than in the connected floodplain. According to the result of principal component analysis (PCA) using environmental data, the environments of the connected floodplain and the isolated floodplain were separated by soil moisture contents, soil texture and distribution altitude of the vegetation. The results of detrended correspondence analysis (DCA) using vegetation data showed that the isolated floodplain was dominated by the hydropythic communities of diverse life form and that the connected floodplain was dominated by the hygrophytic communities that endure disturbance. In conclusion, it is thought that the vegetation of the floodplain changed to the lentic wetland vegetation dominated by diverse hydrophytes as the floodplain was isolated from the channel by artificial levees.