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      • 신경근전기자극에 의한 척수운동신경원의 흥분성 변화

        이정우,김태열,이인학,이준희,Lee, Jeong-Woo,Kim, Tae-Youl,Lee, In-Hak,Lee, Joon-Hee 대한임상전기생리학회 2003 대한임상전기생리학회지 Vol.1 No.1

        The purpose of this study was to determine the effect of neuromuscular electrical stimulation(NMES) on the alteration of spinal motor neuron excitability. In this article, I would like to experiment on a standard capacity of clinical electrophysiology, a difference in applying methods and a clinical efficiency of NMES by Nerve conduction velocity. We used normal eight subjects without neuromuscular disease and all subjects participated 3 session, which at least 1 week between session. Participants classified according to each group in Antagonist, Agonist, Antagonist-Agonist by the NMES. The test was measured continuously pre test, post-test, post 20 minute test by EMG including H reflex, F wave, motor nerve conduction velocity(MNCV). The following results were obtained; 1. H-reflex latencies and H/M intervals were significantly increased in agonist and antagonist-agonist group(p<.01). 2. H-reflex amplitudes and H/M ratios were significantly decreased in agonist and antagonist-agonist group(p<.01). In agonist group, H-reflex amplitudes and H/M ratios were more significantly decreased than antagonist group. 3. F-wave latencies were significantly increased in agonist and antagonist-agonist group(p<.01). F/M intervals were significantly increased in antagonist-agonist group(p<.01). F wave conduction velocities were significantly increased in agonist and antagonist-agonist group(p<.01) but F/M ratios were not significant. 4. MNCV were significantly decreased in agonist(p<.01). These results lead us to the conclusion that agonist and Antagonist-agonist was significantly decreased excitability of spinal motor neuron. Conversely, Antagonist does not decreased. Therefore, A further direction of this study will be to provide more evidence that NMES have an effect on excitability of spinal motor neurons in UMN syndrome.

      • KCI등재후보

        아미설프라이드로 유발된 고프로락틴혈증: 예비 연구

        이정우,박영민,이승환,강승걸,이분희,박은진,Lee, Jung-Woo,Park, Young-Min,Lee, Seung-Hwan,Kang, Seung-Gul,Lee, Bun-Hee,Park, Eun-Jin 한국정신신체의학회 2011 정신신체의학 Vol.19 No.1

        연구목적: 고프로락틴혈증은 항정신병약물로 인한 흔한 부작용이다. 그럼에도 불구하고 이러한 고프로락틴혈증에 대한 임상가들의 관심은 적은 편이다. 왜냐하면 고프로락틴혈증으로 인한 부작용의 심각성이 널리 알려지지 않았기 때문이다. 특히 아미설프라이드로 인한 고프로락틴혈증에 대한 국내 연구는 전무한 실정이다. 본 연구에서는 한국인에서의 아미설프라이드로 인한 프로락틴 수치의 변화를 알아보고자 한다. 방 법: 2008년 1월부터 2010년 12월까지 일산백병원 신경정신과의 외래와 입원 환자 24명을 대상으로 의무기록을 검토하여 자료를 분석하였다. 이를 통해 아미설프라이드 사용 전후의 프로락틴 수치의 변화를 비교하였다. 또한 아미설프라이드 용량, 투약 기간과 프로락틴 수치 변화율과의 상관관계를 통계적으로 분석하였다. 결 과: 아미설프라이드를 투여한 모든 환자에서 고프로락틴혈증이 발생하였다. 아미설프라이드 투여 후의 프로락틴 수치는 투여 전 보다 유의하게 상승하였다(z=-3.702, p=0.000). 아미설프라이드 용량과 프로락틴 상승의 정도는 유의한 상관관계를 보였으나(r=0.61, p=0.002), 아미설프라이드 투여 기간과 프로락틴 상승의 정도는 유의한 상관관계를 보이지 않았다. 또한 아미설프라이드 용량과 프로락틴 수치 변화율은 유의한 상관관계를 보이지 않았다. 결 론: 아미설프라이드를 포함한 항정신병약물은 프로락틴 수치를 증가시켜 장 단기간의 부작용을 발생시킬 수 있다. 따라서 아미설프라이드를 사용하는 임상의는 프로락틴 수치를 정기적으로 측정하여야 하며 고프로락틴혈증과 관련된 부작용을 평가하여야 한다. Objective: Hyperprolactinemia is common side effect associated with antipsychotics use. Nevertheless, hyperprolactinemia is relatively neglected by clinician. Especially, there is no study related to amisulprideinduced hyperprolactinemia in korea. This study aimed to determine whether amisulpride can be induced hyperprolactinemia in Korean psychiatric patients. Methods: This study methodology consisted of a retrospective review of medical charts and prolactin levels. Serum prolactin levels were measured in 24 Korean patients(12 males and 12 females) with psychosis who were treated over 400mg of amisulpride per day. Results: All patients had hyperprolactinemia. Prolactin levels significantly increased after receiving amisulpride(z=-3.702, p=0.000). The prolactin level was significantly higher in females($156.29{\pm}63.75$ng/mL) than in males($69.04{\pm}39.91$ng/mL) after administering amisulpride(p=0.000). There was a correlation between dosage and prolactin levels(r=0.61, p=0.002). However, there was no correlation between duration of treatment and prolactin levels. Conclusions: Antipsychotics, especially amisulpride can increase serum prolactin levels and may results in short and long term side effects. Routine clinical assessment of initial and additional prolactin level and associated symptoms should be done

      • KCI등재후보

        역방향 조사방식을 통한 동적쐐기의 품질관리

        이정우,홍세미,서태석,Lee Jeong Woo,Hong Semie,Suh Tae Suk 한국의학물리학회 2004 의학물리 Vol.15 No.3

        쐐기형태의 선량분포를 만드는 데 이용되는 선형가속기에 장착된 동적쐐기(EDW; Enhanced Dynamic Wedge)의 품질관리를 위한 간단한 방법을 고안하였다. 선량 프로파일의 품질관리를 위해서는 필름 선량측정 장비와 필름 스캐너, 고 에너지 선량 측정용 필름, 필름 농도계, 삼차원 치료 계획 장치가 사용되었다. 역방향 60$^{\circ}$ 동적쐐기를 각각 한 필름에 조사(이하 60$^{\circ}$REWP; 60$^{\circ}$ Reversed Wedge Pair)하고, 이를 통해 얻어진 선량 프로파일의 선량 대칭도를 정량적으로 분석하였으며, 동적쐐기 구동이 중간에 멈춘 경우 이를 보상하는 부분 보상조사(Partial treatment mode)도 비교하였다. 또한 측정 된 자료들을 구간선량표(Golden STT; Segmented Treatment Table) 로 구현한 삼차원 치료 계획 장치의 계산치와 비교하였다 60$^{\circ}$REWP의 실험을 통해 역방향 쐐기의 효과가 1% 이내에서 잘 상쇄되었음을 알 수 있었으며 이 자료를 기준으로 한 품질관리의 타당성을 확보할 수 있었다. 실효쐐기인자의 품질관리를 위해서는 쐐기 각도 $10^{\circ}$, 15$^{\circ}$, 20$^{\circ}$, 25$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$, 60$^{\circ}$에 대해 실측하였고, 구간선량표에서 보정인자를 유도하여 동적쐐기 조사 시 자동으로 생성되는 로그 파일을 참조하여 실효 쐐기인자 계산치를 얻어내어 비교하였다. 이 방법을 통해 별도의 측정 장비 없이 용이하게 쐐기인자의 이상 유무를 파악할 수 있었다. 기존의 복잡한 품질관리의 방법을 단순화하고 효율을 극대화시킴으로써 측정에서 분석까지 1시간 내에 동적 쐐기의 품질관리를 수행할 수 있었다. 동적쐐기는 금속쐐기와 달리 선량률과 Y축 콜리메이터의 움직임에 따라 부정확도의 잠재가능성을 갖고 있으므로 수시 품질관리가 필수적인데 본 연구방법을 이용하면 단순하면서도 효율을 극대화할 수 있어 동적쐐기를 이용한 방사선치료의 안전도를 높일 수 있었다. A simplistic quality assurance (QA) method was designed for a Linac built-in enhanced dynamic wedge (EDW), which can be utilized to make wedged beam distributions. For the purpose of implementing the EDW symmetry QA, a film dosimetry system, low speedy dosimetry film, film densitometer and 3D RTP system were used, and the films irradiated by means of a 60$^{\circ}$ Reversed wedge pair (REWP) method. The profiles were then analyzed in terms of their symmetries, including partial treatment, which is the case of stopping it abruptly during EDW irradiation, and the measured and calculated values compared using the Cad Plan Golden Segmented Treatment Table (Golden STT). The result of this experiment was in good agreement, within 1 %, of the 'reversed wedge pair counterbalance effect'. For the QA of the effective wedge factor (EWF), the authors measured EWFs in relation to the 10$^{\circ}$, 15$^{\circ}$, 20$^{\circ}$, 25$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$ and 60$^{\circ}$ EDW, which were compared with the calculated values using the correction factor derived from the Golden STT and the log files produced automatically during the process of EDW irradiation. By means of this method it was capable of check up the safety of effective wedge factor without any other dosimetry system. The EDW QA was able to be completed within 1 hour from irradiation to analysis as a consequence of the simplified QA procedure, with maximized effectiveness. Unlike the metal wedge system, the EDW system was heavily dependent on the dose rates and jaw movements; therefore, its features could potentially cause inaccuracy. The frequent simplistic QA for the EDW is essential, and could secure against the flaw of dynamic treatment that uses the EDW.

      • KCI등재

        Inverse Verification of the Dose Distribution for Intensity Modulated Radiation Therapy Patient-specific Quality Assurance Using Dynamic MLC Log Files

        이정우,Jeong-Hoon Park,Jin-Beom Chung,박지연,최보영,서태석,Doo-Hyun Lee,Semie Hong,Kyoung-Sik Choi 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.4

        The aim of this study was to investigate a novel method for verification of the dose distribution for intensity modulated radiation therapy (IMRT) patient-specific quality assurance (QA) using dynamic multi-leaf collimator (DMLC) log files (Dynalog files). Dynalog files are recorded every 50 ms by using a MLC controller during the IMRT treatment. Dynalog files contain actual MLC positional information for various delivered dose fractions. As the nonuniform fluence is directly influenced by the MLC positional accuracy, our method for IMRT patient-specific QA can be performed using this information. Three nasopharyngeal cancer patients were selected for the evaluation. We developed an in-house program to convert MLC log files from an MLC controller to delivered MLC (dMLC) field files for the interface between the MLC controller and the treatment planning system. The in-house software, DMLC field file (DFF) converter, was written using programming language (Visual C++ 2005, Microsoft, Redmond, WA, USA). For inverse planning, Eclipse (v. 6.5, Varian, Palo Alto, USA) was used. The MLC log files were converted to dMLC files. The IMRT plans were recalculated and compared with the original plans. Comparisons were done via planar dose distributions using OP-IMRT software (v. 1.4, Wellhofer Dosimetrie, Germany) and dose volume histograms (DVHs) for targets and organs at risk (OARs). Gamma index (dose difference: 3%, distance to agreement: 3 mm) calculations were also performed for a quantitative analysis. There were significant differences (maximum dose difference: 587 cGy, maximum volume difference at 3000 cGy: 17%) in the DVHs of the parotid glands between planned MLC (pMLC)- based and delivered MLC (dMLC)-based inverse IMRT QA (IVQA) plans for all three patients. The histograms showed an increased dose-volume in the dMLC-based IVQA deliveries compared to reference (Ref.) IMRT plans. Based on the present study, we can confirm the availability of our new approach to perform IMRT patient-specific QA providing a convenient and clear tool for IMRT dose verification. In the future, this method should be available for inverse on-treatment dose verification and for pre-treatment IMRT QA. The aim of this study was to investigate a novel method for verification of the dose distribution for intensity modulated radiation therapy (IMRT) patient-specific quality assurance (QA) using dynamic multi-leaf collimator (DMLC) log files (Dynalog files). Dynalog files are recorded every 50 ms by using a MLC controller during the IMRT treatment. Dynalog files contain actual MLC positional information for various delivered dose fractions. As the nonuniform fluence is directly influenced by the MLC positional accuracy, our method for IMRT patient-specific QA can be performed using this information. Three nasopharyngeal cancer patients were selected for the evaluation. We developed an in-house program to convert MLC log files from an MLC controller to delivered MLC (dMLC) field files for the interface between the MLC controller and the treatment planning system. The in-house software, DMLC field file (DFF) converter, was written using programming language (Visual C++ 2005, Microsoft, Redmond, WA, USA). For inverse planning, Eclipse (v. 6.5, Varian, Palo Alto, USA) was used. The MLC log files were converted to dMLC files. The IMRT plans were recalculated and compared with the original plans. Comparisons were done via planar dose distributions using OP-IMRT software (v. 1.4, Wellhofer Dosimetrie, Germany) and dose volume histograms (DVHs) for targets and organs at risk (OARs). Gamma index (dose difference: 3%, distance to agreement: 3 mm) calculations were also performed for a quantitative analysis. There were significant differences (maximum dose difference: 587 cGy, maximum volume difference at 3000 cGy: 17%) in the DVHs of the parotid glands between planned MLC (pMLC)- based and delivered MLC (dMLC)-based inverse IMRT QA (IVQA) plans for all three patients. The histograms showed an increased dose-volume in the dMLC-based IVQA deliveries compared to reference (Ref.) IMRT plans. Based on the present study, we can confirm the availability of our new approach to perform IMRT patient-specific QA providing a convenient and clear tool for IMRT dose verification. In the future, this method should be available for inverse on-treatment dose verification and for pre-treatment IMRT QA.

      • KCI등재
      • 소아에서 수술 후 발생한 장폐색에 대한 복강경 유착박리술의 초기 경험

        이정우,정은영,박우현,최순옥,Lee, Jeongwoo,Jung, Eunyoung,Park, Woo-Hyun,Choi, Soon-Ok 대한소아외과학회 2013 소아외과 Vol.19 No.1

        The purpose of this study is to analyze the early experience of the laparoscopic adhesiolysis for the intestinal obstruction due to postoperative adhesion. Seven patients were included in this study. The median age of those patients was 13, and there were 3 males and 4 females. Previous diagnosis and surgical procedure were various in seven cases, including small bowel resection with tapering enteroplasty, Boix-Ochoa fundoplication, Ladd's procedure with appendectomy, mesenteric tumor resection with small bowel anastomosis, ileocecal resection and anastomosis, primary gastric repair, and both high ligation. A successful laparoscopic adhesiolysis was performed in one who had high ligation for inguinal hernia and had a single band adhesion. Six out of 7 (86%) cases needed to convert open surgery due to multiple and dense type of adhesion. In conclusion, laparoscopic approach with postoperative small bowel adhesion seems safe. However, it might be prudently considered because of high rates of conversion in children.

      • KCI등재
      • KCI등재후보

        MR Polishing을 이용한 커버글라스의 굽힘강도 향상에 관한 연구

        이정우,김지훈,임동욱,하석재,Lee, Jeong-woo,Kim, Ji-Hun,Lim, Dong-Wook,Ha, Seok-Jae 한국금형공학회 2022 한국금형공학회지 Vol.16 No.1

        Coverglass of electronic equipments is thinner and slimmer, so the glass must have good bending strength. In these days, the polishing edge of glass is used by solid tool like grinding wheel. But solid tool leave micro crack or edge chipping in edge of glass. MR polishing is an optimal method by polishing edge of glass. MR polishing is used MR fluid that is a liquid tool. MR polishing doesn't leave tool path or residual stress, micro crack and edge chipping unlike grinding wheel polishing. In this paper, the results of grinding and MR polishing were compared and analyzed to improve bending strength by minimizing edge chipping of cover glass. It was derived that the depth and size of cracks have a significant influence on the bending strength of the glass edge. The edges of the glass using MR grinding were analyzed to have a better surface and higher bending strength than the glass using abrasive wheel grinding. It was confirmed that MR polishing had an effect on strength improvement by effectively removing cracks in the specimen.

      • 전기생리학적 기전에 근거한 망막 모델의 제안과 시공간적 응답의 분석

        이정우,채승표,조진호,김명남,Lee, Jeong-Woo,Chae, Seung-Pyo,Cho, Jin-Ho,Kim, Myoung-Nam 대한전자공학회 2002 電子工學會論文誌-SC (System and control) Vol.39 No.6

        본 논문에서는 망막의 전기생리학적 기전을 바탕으로 실제 망막과 유사한 기능 및 응답 특성을 갖는 망막 모델을 제안하였다. 시세포에서 양극세포까지는 기존에 연구된 여러 망막 모델들을 종합하여 모델링하였고, 3 NDP 기전을 이용하여 움직임 정보를 검출한다고 알려져 있는 아마크린세포와 양극세포 터미널에 관한 새로운 모델을 제안하였다. 이 모델의 평가를 위하여, 공간상의 동적 자극과 정지 자극에 대한 응답 특성을 비교 분석을 하였을 뿐만 아니라 자극의 움직임 속도에 따른 특성에 대한 분석도 수행하여 제안한 망막 모델을 검증하였다. 본 연구결과는 움직임 정보를 검출하기 위한 비전 시스템에 대한 인간 시각 시스템의 적용 및 생체에 이식할 수 있는 인공 망막의 개발을 위한 기초 연구에 이용될 수 있을 것이다. Based on electrophysiological retina mechanism, a retina model is proposed, which has similar response characteristics compared with the real primate retina. Photoreceptors, horizontal cells, and bipolar cells are modeled based on the previously studied retina models. And amacrine cells known to have relation to movements detection, and bipolar cell terminals are newly modeled using 3 NDP mechanism. The proposed model verified by analyzing the spatial response characteristics to stationary and moving stimuli, and characteristics for different speeds. Through this retina model, human vision system could be applied to computer vision systems for movement detection, and it could be the basic research for the implantable artificial retina.

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