• Title/Summary/Keyword: local resonance

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Dermatofibrosarcoma Protuberans on the Occipital Scalp Showed Uncommon Presentation: A Case Report (비전형적 임상양상을 보이는 후두부의 융기성 피부 섬유 육종에 대한 증례보고)

  • Jiwon Jeong;Chul Hoon Chung;SeongJin Cho
    • Korean Journal of Head & Neck Oncology
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    • v.40 no.1
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    • pp.49-53
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    • 2024
  • Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma, with an incidence of about 0.8% to 5% per million people per year, accounting for 1% of soft tissue sarcomas. In its early stage, DFSP is typically found as a violet or pinkish macule or patch, and it can develop into a palpable mass with ulceration or bleeding. The standard treatment for DFSP is wide local excision of the tumor with a 2- to 3-cm negative margin, and radiation therapy or chemotherapy can be conducted with surgical treatment. A 35-year-old man had a palpable mass on the left side of his occipital scalp without color change, ulceration, or bleeding, which typically are present in malignancy. A magnetic resonance imaging (MRI) scan showed a 3-cm homogenous enhanced mass without adhesion between the scalp and the mass. Unexpectedly, a biopsy revealed the round mass to be DFSP. A wide excision and rotation of the scalp flap were performed. The patient recovered without any complications and received adjuvant radiotherapy at a dose of 60 Gray (Gy) for six weeks. There was no recurrence through six months of follow-up. Here we report this unique case of DFSP with atypical presentation.

Carbon monoxide poisoning-induced encephalopathy in a carbon dioxide arc welder: a case report

  • Seongwon Ma;Hoekyeong Seo;Dong Joon Park;Byeongju Choi;Shinhee Ye
    • Annals of Occupational and Environmental Medicine
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    • v.34
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    • pp.19.1-19.9
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    • 2022
  • Background: It is widely known that carbon dioxide (CO2) arc welding generates carbon monoxide (CO). However, to the best of our knowledge, no case reports have been published regarding CO poisoning in CO2 arc welders. Therefore, we aimed to report a case of CO poisoning-induced encephalopathy in a CO2 arc welder in the Republic of Korea to inform about the dangers of CO exposure among CO2arc welders. Case presentation: A 40-year-old man working as a CO2 arc welder for 15 years visited a local hospital with a tremor, involuntary urination, and speaking gibberish, on April 9, 2019. He stated that he had intermittent headache and forgetting symptoms for the last 5 years, and had been lost on the way to work several times. On April 9, 2019, he was diagnosed with CO poisoning-induced encephalopathy through brain magnetic resonance imaging. He received hyperbaric oxygen therapy, and some of his symptoms improved. According to the exposure assessment of his work environment, he was continuously exposed to high concentrations of CO for 15 years while operating CO2 arc welding machines. Conclusions: After evaluating the patient's work environment and evaluating his medical history, we concluded that his encephalopathy was caused by CO exposure during CO2 arc welding. Thus CO2 arc welders must be aware of the risk of CO poisoning and strive to avoid CO exposure.

Extrapleural Pneumonectomy for the Anterior Mediastinal Liposarcoma with Invasion of Pleura and Lung -1 case report - (흉막 및 폐를 침범한 전종격동 지방육종에서의 흉막외 폐전적출술 - 1예 보고 -)

  • 박천수;김영태;성숙환;김주현
    • Journal of Chest Surgery
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    • v.37 no.3
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    • pp.286-291
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    • 2004
  • Mediastinum is a very rare primary site of liposarcoma. In general, wide surgical excision with adequate resection margin is the treatment of choice for lipesarcoma. We experienced a case of liposarcoma in a 24 year-old male who complained of dyspnea and chest discomfort. Symptoms had been developed a month before admission, and the intensity had been gradually increased. He visited another general hospital, and there he received left closed thoracostomy because hemothorax was suspected. Afterwards, he was transferred to our hospital without a specific diagnosis, on review of outside chest computed tomography film, mass shadow was detected in the mediastinum. For the further evaluation, we checked the chest sonography and chest magnetic resonance imaging. MRI showed 10 cm sized mass contacted with pulmonary artery trunk and left main pulmonary artery. The radiologist strongly suggested sarcoma. On the 4th day after admission, we performed emergent exploratory left thoracotomy for hematoma evacuation because mediastinal shifting progressed and heart rate was increased. Biopsy confirmed that the evacuated materials were extraskeletal myxoid chondresarcoma, so we performed extrapleural left pneumonectomy including diaphragm and a part of the pericardium. The final pathologic diagnosis was myxoid/round cell liposarcoma. He was discharged without complication and systemic chemotherapy was scheduled to begin 2 month later. During chemotherapy, local recurrence and peritoneal metastasis developed, and he died 10 month after the surgical excision. We report this case with reviewal of literature.

Study on Factors Associated with the Rise in Grade of Nursing Management Fee among Korean Hospitals (병원급 이상 의료기관의 간호등급 상승 요인 분석)

  • Choi, Hyun-Min;Han, Nam-Kyung;Lee, Sang-Kyu;Kim, Han-Sung;Choi, Sungkyoung;Chung, Woojin
    • Health Policy and Management
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    • v.25 no.1
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    • pp.40-52
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    • 2015
  • Background: The purpose of this study was to analyze the increase in Grade of Nursing Management Fee of medical institutions and establish a reasonable government policy by examining which factors affect the increase of nurse staffing. Methods: Analyzing data collected from the Health Insurance Review & Assessment Service resource management department with targets of 1,104 medical institutions. The study period was 5 years from June 30, 2008 to June 30, 2013. SAS ver. 9.2 (SAS Institute Inc., Cary, NC, USA) was used for statistical analysis. The data was analyzed by a chi-square test and also conducted muiltivariate logistic regression analyses for variables of basic characteristics, human resource characteristics, and material resources. Results: Adjusted odds ratio (AOR) of the rise in Grade of Nursing Management Fee among other hospitals compared to hospitals owned by government or universities was 0.264. The AOR in hospitals established after November 2006 compared to those before June 1995 was 2.383. The AOR in Gangwon, Chungcheng South, and Jeolla South Provinces compared to Seoul was 0.084, 0.036, and 0.194, respectively. The AOR in hospitals with more than 6.75 specialists per 100 beds compared to those with less than 6.75 specialists per 100 beds was 7.514. The AOR in hospitals with more than 17.48 nurse per 100 beds compared to those with less than 17.48 nurse per 100 beds was 3.300. The AOR in hospitals with 50% to 75% bed utilization, 75% to 90% bed utilization and more than 90% bed utilization compared to those with less than 50% bed utilization was 5.428, 9.884, and 10.699, respectively. The AOR in hospitals with one magnetic resonance imaging (MRI) and more than two MRI compared to those with no MRI was 2.018 and 2.942, respectively. Conclusion: This result has showed policies to induce the rise in Grade of Nursing Management Fee among old hospitals and the incentive system for local medical institutions are needed. Also we need to develop a governmental policy for medium-small hospitals with low operation rate of beds and insufficient medical personnel and number of equipment in hospitals.

Dual-Band Six-Port Direct Conversion Receiver with I/Q Mismatch Calibration Scheme for Software Defined Radio (Software Defined Radio를 위한 I/Q 부정합 보정 기능을 갖는 이중 대역 Six-Port 직접변환 수신기)

  • Moon, Seong-Mo;Park, Dong-Hoon;Yu, Jong-Won;Lee, Moon-Que
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.6
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    • pp.651-659
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    • 2010
  • In this paper, a new six-port direct conversion receiver for high-speed multi-band multi-mode wireless communication system such as software defined radio(SDR) is proposed. The designed receiver is composed of two CMOS four-port BPSK receivers and a dual-band one-stage polyphase filter for quadrature LO signal generation. The four-port BPSK receiver, implemented in 0.18 ${\mu}m$ CMOS technology for the first time in microwave-band, is composed of two active combiners, an active balun, two power detector, and an analog decoder. The proposed polyphase filter adopt type-I architecture, one-stage for reduction of the local oscillator power loss, and LC resonance structure instead of using capacitor for dual-band operation. In order to extent the operation RF bandwidth of the proposed six-port receiver, we include I/Q phase and amplitude calibration scheme in the six-port junction and the power detector. The calibration range of the phase and amplitude mismatch in the proposed calibration scheme is 8 degree and 14 dB, respectively. The validity of the designed six-port receiver is successfully demonstrated by modulating M-QAM, and M-PSK signal with 40 Msps in the two-band of 900 MHz and 2.4 GHz.

A Neurobiological Measure of General Intelligence in the Gifted (뇌기능영상 측정법을 이용한 영재성 평가의 타당성 연구)

  • Cho, Sun-Hee;Kim, Heui-Baik;Choi, Yu-Yong;Chae, Jeong-Ho;Lee, Kun-Ho
    • Journal of Gifted/Talented Education
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    • v.15 no.2
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    • pp.101-125
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    • 2005
  • We applied functional magnetic resonance imaging (fMRI) techniques to examine whether general intelligence (g) could be assessed using a neurobiological signal of the brain. Participants were students in a national science academy and several local high schools. They were administered diverse intelligence (RAPM and WAIS) and creativity tests (TTCT-figural and TTCT-verbal). Forty of them were scanned using fMRI while performing complex and simple g tasks. In brain regions of greater blood flow in complex compared with simple g tasks, the gifted group with an exceptional g level was not significantly different from the average group with an ordinary g level: both of them activated the lateral prefrontal, anterior cingulate, posterior parietal cortices. However, the activation levels of the gifted group were greater than those of the average group, particularly in the posterior parietal cortex. Correlation analysis showed that the activity of the posterior parietal cortex has the highest correlation ($(r=0.73{\sim}0.74)$) with individual g levels and other regions also have moderate correlation ($(r=0.53{\sim}0.66)$). On the other hand, two-sample t test showed a striking contrast in intelligence tests scores between the gifted and the average group, whereas it did not show in creativity tests scores. These results suggest that it is within the bounds of possibility that a neurobiological signal of the brain is used in the assessment of the gifted and also suggest that creativity has to be given a great deal of weight on the assessment of the gifted.

Clinical application of RapidArc volumetric modulated arc therapy as a component in whole brain radiation therapy for poor prognostic, four or more multiple brain metastases

  • Lee, Seung-Heon;Lee, Kyu-Chan;Choi, Jin-Ho;Kim, Hye-Young;Lee, Seok-Ho;Sung, Ki-Hoon;Kim, Yun-Mi
    • Radiation Oncology Journal
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    • v.30 no.2
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    • pp.53-61
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    • 2012
  • Purpose: To determine feasibility of RapidArc in sequential or simultaneous integrated tumor boost in whole brain radiation therapy (WBRT) for poor prognostic patients with four or more brain metastases. Materials and Methods: Nine patients with multiple (${\geq}4$) brain metastases were analyzed. Three patients were classified as class II in recursive partitioning analysis and 6 were class III. The class III patients presented with hemiparesis, cognitive deficit, or apraxia. The ratio of tumor to whole brain volume was 0.8-7.9%. Six patients received 2-dimensional bilateral WBRT, (30 Gy/10-12 fractions), followed by sequential RapidArc tumor boost (15-30 Gy/4-10 fractions). Three patients received RapidArc WBRT with simultaneous integrated boost to tumors (48-50 Gy) in 10-20 fractions. Results: The median biologically effective dose to metastatic tumors was 68.1 $Gy_{10}$ and 67.2 $Gy_{10}$ and the median brain volume irradiated more than 100 $Gy_3$ were 1.9% (24 $cm^3$) and 0.8% (13 $cm^3$) for each group. With less than 3 minutes of treatment time, RapidArc was easily applied to the patients with poor performance status. The follow-up period was 0.3-16.5 months. Tumor responses among the 6 patients who underwent follow-up magnetic resonance imaging were partial and stable in 3 and 3, respectively. Overall survival at 6 and 12 months were 66.7% and 41.7%, respectively. The local progression-free survival at 6 and 12 months were 100% and 62.5%, respectively. Conclusion: RapidArc as a component in whole brain radiation therapy for poor prognostic, multiple brain metastases is an effective and safe modality with easy application.

Evaluation of Site-specific Seismic Response Characteristics at Town Fortress Areas Damaged by Historical Earthquakes (역사 지진 피해 발생 읍성 지역에 대한 부지 고유의 지진 응답 특성 평가)

  • Sun, Chang-Guk;Chung, Choong-Ki;Kim, Dong-Soo;Kim, Jae-Kwan
    • The Journal of Engineering Geology
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    • v.17 no.1 s.50
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    • pp.1-13
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    • 2007
  • In order to evaluate the local site effects at two town fortress areas in Korea where stone parapets were col-lapsed by historical earthquakes, site characteristics were assessed using site investigations such as borehole drillings and seismic tests. Equivalent-linear site response analyses were conducted based on the shear ways velocity ($V_s$) profiles and geotechnical characteristics determined from site investigations. The study sites are categorized as site classes C and B according to the mean $V_s$ to 30 m ranging from 500 to 850 m/s, and their site periods are distributed in the short period range of 0.06 to 0.16 sec, which contains the natural period of fortress wall and stone parapet. From the results of site response analyses in the study areas, for site class C indicating most of site conditions, contrary to site class B, the short-period (0.1-0.5 sec) and mid-period (0.4-2.0 sec) site coefficients, $F_a$ and $F_v$ specified in the Korean seismic design guide, underestimate the ground motion in short-period band and overestimate the ground motion in mid-period band, respectively, due to the high amplification in short period range, which represent the site-specific seismic response characteristics. These site-specific response characteristics indicate the potential of resonance in fortress walls during earthquake and furthermore could strongly affect the collapse of parapets resulted from seismic events in historical records.

Variation of Harbor Oscillations in Yeongil Bay (영일만 항만에서의 부진동 변화에 관한 연구)

  • Jeon Min-Su;Lee Joong-Woo;Jeong Jae-Hyun;Yang Sang-Yong;Jeong Young-Hwan
    • Journal of Navigation and Port Research
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    • v.30 no.6 s.112
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    • pp.533-539
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    • 2006
  • Today the harbor oscillation problems are the most significant factor to design harbors serving the very large ships. Large vessels moored in the elastic hawsers at the coastal harbors are often displaced due to the resonance between the long period waves and mooring system. The cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes remarkable. The most significant harbor which is confronted with harbor oscillation problem in Korea is the Pohang New Port. Many cases of problems are being notified by the pilot association and local office of MOMAF. However, it is difficult to prevent the arrival of long waves musing oscillation within this harbor. Moreover, government already started new port plan at the mouth of Yeongil Bay without treating problems occurred in the Pohang New Port. This study deals with the variation of harbor oscillation due to the construction of 4.1km breakwater at the bay mouth and new port plan. Numerical method used are fairly standard form from the extended mild slope equation The obtained numerical results were compared with the field measurement from the previous study and this will bring a certain level of discussion and consideration of variation in the future port development.

Resection and Observation for Brain Metastasis without Prompt Postoperative Radiation Therapy

  • Song, Tae-Wook;Kim, In-Young;Jung, Shin;Jung, Tae-Young;Moon, Kyung-Sub;Jang, Woo-Youl
    • Journal of Korean Neurosurgical Society
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    • v.60 no.6
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    • pp.667-675
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    • 2017
  • Objective : Total resection without consecutive postoperative whole brain radiation therapy is indicated for patients with a single or two sites of brain metastasis, with close follow-up by serial magnetic resonance imaging (MRI). In this study, we explored the effectiveness, usefulness, and safety of this follow-up regimen. Methods : From January 2006 to December 2015, a total of 109 patients (76 males, 33 females) underwent tumor resection as the first treatment for brain metastases (97 patients with single metastases, 12 with two metastases). The mean age was 59.8 years (range 27-80). The location of the 121 tumors in the 109 patients was supratentorial (n=98) and in the cerebellum (n=23). The origin of the primary cancers was lung (n=45), breast (n=17), gastrointestinal tract (n=18), hepatobiliary system (n=8), kidney (n=7), others (n=11), and unknown origin (n=3). The 121 tumors were totally resected. Follow-up involved regular clinical and MRI assessments. Recurrence-free survival (RFS) and overall survival (OS) after tumor resection were analyzed by Kaplan-Meier methods based on clinical prognostic factors. Results : During the follow-up, MRI scans were done for 85 patients (78%) with 97 tumors. Fifty-six of the 97 tumors showed no recurrence without adjuvant local treatment, representing a numerical tumor recurrence-free rate of 57.7%. Mean and median RFS was 13.6 and 5.3 months, respectively. Kaplan-Meier analysis revealed the cerebellar location of the tumor as the only statistically significant prognostic factor related to RFS (p=0.020). Mean and median OS was 15.2 and 8.1 months, respectively. There were no significant prognostic factors related to OS. The survival rate at one year was 8.2% (9 of 109). Conclusion : With close and regular clinical and image follow-up, initial postoperative observation without prompt postoperative radiation therapy can be applied in patients of brain metastasi(e)s when both the tumor(s) are completely resected.