• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.713-717
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• 2001

This paper focuses on a network model for GCTs which can be used to investigate high power circuits with or without using RC-snubbers. The series connection of GCTs is commonly applied in the high power inverter field. Here expensive and space-consuming snubbers are applied, to overcome the problem of an asymmetric distribution of the blocking voltage among the single GCTs. As an alternative to large snubbers, a new active gate drive concept is proposed and investigated by simulation.

• Clinical and Experimental Pediatrics
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• 제58권10호
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• pp.386-391
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• 2015

Purpose: To evaluate the outcomes and prognostic factors in children with extracranial germ cell tumors (GCTs) treated at a single institution. Methods: Sixty-six children diagnosed with extracranial GCTs between 1996 and 2012 were included in the study. Primary treatment was surgical excision, followed by six cycles of cisplatin-based chemotherapy. The survival rates were compared according to the International Germ Cell Cancer Cooperative Group classification used for GCTs in adults to validate the classification guidelines for GCTs in children. Results: The median patient age was 4.4 years. In 34 patients (51.5%), the primary tumor site was the gonad. Extragonadal GCTs were detected in 32 patients. The 5-year overall survival and event-free survival (EFS) were $92.0%{\pm}3.5%$ and $90.4%{\pm}3.7%$, respectively. In univariate analysis, tumor histology, metastasis, and elevated alpha-fetoprotein were not prognostic factors in children with extracranial GCTs. However, EFS was poorer in patients with mediastinal disease (n=12, $66.7%{\pm}13.6%$) than in those with nonmediastinal disease (n=54, $96.0%{\pm}2.8%$) (P=0.001). The 5-year EFS was lower in patients older than 10 years, (n=21, $80.0%{\pm}8.9%$) compared with those younger than 10 years (n=45, $95.2%{\pm}3.3%$) (P=0.04). Multivariate analysis identified the mediastinal tumor site as the only independent prognostic factor. Conclusion: The prognosis of children with extracranial GCTs was favorable. However, nongerminomatous mediastinal tumors were associated with poor survival in children. Further research is needed to improve the prognosis of children with malignant mediastinal GCTs.

• Clinical and Experimental Reproductive Medicine
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• 제43권1호
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• pp.1-8
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• 2016

Granulosa cell tumors (GCTs) are rare sex cord-stromal tumors that have been studied for decades. However, their infrequency has delayed efforts to research their etiology. Recently, mutations in human GCTs have been discovered, which has led to further research aimed at determining the molecular mechanisms underlying the disease. Mouse models have been important tools for studying GCTs, and have provided means to develop and improve diagnostics and therapeutics. Thus far, several genetically modified mouse models, along with one spontaneous mouse model, have been reported. This review summarizes the phenotypes of these mouse models and their applicability in elucidating the mechanisms of granulosa cell tumor development.

• Annals of Clinical Neurophysiology
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• 제22권2호
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• pp.109-111
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• 2020

Germ-cell tumors (GCTs) are common in the central nervous system. GCTs are highly sensitive to radiotherapy and chemotherapy and can be cured without radical surgery. However, this tumor produces nonspecific imaging findings, and its rarity can make diagnosis challenging. Here we report a case in which the first diagnosis was uncertain and follow-up imaging revealed intramedullary germinoma. The patient underwent chemotherapy and radiotherapy after the diagnosis.

• 대한영상의학회지
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• 제84권1호
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• pp.275-279
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• 2023

과립 세포 종양은 신체의 모든 부위에서 발생할 수 있으나, 특히 두경부에서 주로 발생하는 드문 양성 연부 종양이며, 이 중 5%-8%가 유방에서 발생한다. 저자들은 드문 부위인 액와부 부유방에 발생한 과립 세포 종양 1예를 보고하고자 한다. 50세 여자에게 2개월 전부터 좌측 액와부에 만져지는 종괴가 있었다. 이학적 검사, 유방 촬영술 및 초음파 소견에서 유방의 악성 종양을 먼저 생각하였다. 조직 검사에서 양성 과립 세포 종양으로 진단되었으며 이후 광범위 국소 절제술을 시행하였다. 환자는 수술 후 2년의 추적 관찰 기간 동안 재발하지 않았다. 대부분의 과립 세포 종양은 양성이지만, 재발의 가능성 때문에 종양의 광범위한 완전 절제와 추적 관찰이 필요하다. 영상의학과 의사는 불필요한 치료를 막기 위해 유방 및 액와부 병변의 감별 진단으로 과립 세포 종양의 특징에 대해 알고 있어야 한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1096-1099
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• 2001

The basic design structure of RC-GCTs (Reserve-Conducting Gate-Commutated Thyristors) is firstly given in this paper. The bulk of wafer is punch-through (PT) type with high resistivity and narrow N-base width. The photo-mask was designed upon the turn-off characteristics of GCT and solution of separation between GCT and diode part. The center part of Si wafer is free-wheeling diode (FWD) and outer is GCT part which has 240 fingers totally. The switching performance of GCT was investigated by Dessis of ISE. The basic manufacture process of 2500V-4500V RC-GCTs was given in this work. Additionally, the local carrier lifetime control by 5Mev proton irradiation was adopted so as to not only to have the softness of reverse recovering for FWD but for reduction of turn-off losses of GCT as well.

• Clinical and Experimental Pediatrics
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• 제54권3호
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• pp.128-132
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• 2011

Purpose: Cisplatin-based chemotherapy has been commonly used for the treatment of intracranial germ cell tumors (IC-GCTs). However, this treatment exhibits some adverse effects such as renal problems and hearing difficulty. Carboplatin-based chemotherapy was administered to pediatric patients with IC-GCTs from August 2004 at the Samsung Medical Center. In this study, we assessed the responses and adverse effects of carboplatin-based chemotherapy in pediatric IC-GCTs patients according to the risk group, and compared the results with those of the previous cisplatin-based chemotherapy. Methods: We examined 35 patients (27 men and 8 women) diagnosed with IC-GCTs between August 2004 and April 2008 and received risk-adapted carboplatin-based chemotherapy at the Samsung Medical Center. Patients were divided into either low-risk (LR) or high-risk (HR) groups and a retrospective analysis was performed using information from the medical records. Results: Although hematological complications were common, hearing difficulties or grade 3 or 4 creatinine level elevation were not observed in patients who underwent carboplatin-based chemotherapy. The frequency of febrile neutropenia did not differ between the risk groups. The overall survival was 100% and event-free survival (EFS) was 95.7%. The EFS rate was 100% in the LR group and 90% in the HR group, respectively. Conclusion: Despite their common occurrence in high-risk patients, no lethal hematological complications were associated with carboplatin-based treatment. The current carboplatin-based chemotherapy protocol is safe and effective for the treatment of pediatric patients with IC-GCTs.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2007년 가을학술발표회
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• pp.502-513
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• 2007

This paper describes the rainfall-induced slope failures caused by infiltration due to prolonged rainfall. The emphasis was on quantifying the effect of fine-grained contents which are influencing on the infiltration rate in the wetting front of initially unsaturated slopes during rainfall. Suction tests by tensiometer were performed for five mixture specimens with varying fine-grained contents and then, numerical analyses for the stability of unsaturated slopes are carried out for different relative densities and mixture portions based on the soil water characteristic curves obtained by GCTS pressure plate. It is shown that the fines are highly influenced on wetting front suction of unsaturated soil slopes. Based on the results, it is found that until 15% fine content is the limit showing different wetting front suction, beyond which the wetting band depth do not affect considerably the stability of unsaturated slopes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.312-315
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• 2003

Basic design of RC-GCTs (Reserve-Conducting Gate-Commutated Thyristors) by novel punch-through (PT) concept with 5,500v rated voltage is described here. A PT and NPT (non punch-through) concept for the same blocking voltage has been compared in detail. The simulation work indicates that GCT with such PT design exhibits that the forward breakdown voltage is 6,400V which is enough for supporting 5500V blocking. Additionally, the real IGCT turn-off in the mode of PNP transistor has been realized. However, the carrier extraction from N-base to gate terminal will be drastic slowly in terms of NPT structure except for the high on-state voltage drop.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.831-835
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• 2014

Background: Predictor factors determining complete response to treatment are still not clearly defined. We aimed to evaluate clinicopathological features, risk factors, treatment responses, and survival analysis of patient with advanced nonseminomatous GCTs (NSGCTs). Materials and Methods: Between November 1999 and September 2011, 140 patients with stage II and III NSGCTs were referred to our institutions and 125 patients with complete clinical data were included in this retrospective study. Four cycles of BEP regimen were applied as a first-line treatment. Salvage chemotherapy and/or high-dose chemotherapy (HDCT) with autologous stem cell transplantation were given in patients who progressed after BEP chemotherapy. Post-chemotherapy surgery was performed in selected patients with incomplete radiographic response and normal tumor markers. Results: The median age was 28 years. For the good, intermediate and poor risk groups, compete response rates (CRR) were, 84.6%, 67.9% and 59.4%, respectively. Extragonadal tumors, stage 3 disease, intermediate and poor risk factors, rete testis invasion were associated with worse outcomes. There were 32 patients (25.6%) with non-CR who were treated with salvage treatment. Thirty-one patients died from GCTs and 94% of them had stage III disease. Conclusions: Even though response rates are high, some patients with GCTs still need salvage treatment and cure cannot be achieved. Non-complete response to platinium-based first-line treatment is a negative prognostic factor. Our study confirmed the need for a prognostic and predictive model and more effective salvage approaches.