• 대한수의학회지
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• 제37권1호
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• pp.41-57
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• 1997

This study was carried out to investigate the effect of selenium on the adriamycininduced renal lesions in male Sprague Dawley rats. A total of 60 Sprague-Dawley male rats were divided into 2 control groups(C1: saline, C2: selenium) and 2 treatment groups(T1: adriamycin, T2: adriamycin+selenium). The rats of the C1 and T1 groups were given normal saline(0.15ml/rat), the rats of the C2 and T2 groups were given sodium selenite(0.5mg/kg) intraperitoneally three days a week for 4 weeks. The treatment groups were dosed intraperitoneally with adriamycin(2mg/kg/day) five days at the second week. Animals were sacrificed at the 1st week, 2nd week and 3rd week after dosing with adriamycin. The morphologic abnormalities of the glomeruli and tubules in the kidney of male rats were examined histopathologically and electron microscopically.The results obtained were as follows : The mean body weight of adriamycin dosed group was significantly decreased as compared with that of control group at 4th week(p<0.05). In adriamycin and selenium dosed group, the mean body weight was decreased until the end of 2nd week but gradually increased from 3rd to 4th week. The histopathological findings of the renal corpuscle in adriamycin dosed group were parietal epithelial cell proliferation, vacuolization of glomerulus, and thickened basement membrane of the parietal epithelium. Proximal convoluted tubules were significantly dilated and the lumens were filled with renal cast. These lesions were generally not very significant in the rats given adriamycin and selenium. The electron microscopical findings of the renal glomerulus in the adriamycin dosed group were focal loss and fusion of the pedicels of the podocyte, and some vacuoles in the cytoplasm of the podocytes. There were numerous cytoplasmic vacuoles in the proximal and distal convoluted tubular cells. However, these ultrastructural changes were not significantly observed in the renal tubules of the rats of adriamycin and selenium dosed group. These results suggest that selenium may act as an inhibitor of the renal lesions induced by adriamycin in male rats.

• 한국전자통신학회논문지
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• 제12권6호
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• pp.989-996
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• 2017

제안된 지향성 펜슬빔 안테나는 절곡된 타원 도체평판을 갖는 도파관 급전부와 포물형 곡면 반사판으로 구성되어 있다. 반사판 뒤에서 삽입된 급전 도파관의 종단 부근 광벽에 위치한 두 개의 사각형 개구는 반사판 초점에 위치하며, 절곡된 타원 평판으로 전자파 에너지를 방출시킨다. 이 평판은 전자파 에너지를 일차 반사시키며, 주 반사판을 향하도록 설계되어 있다. 도파관 종단에 위치한 두 사각형 개구는 안테나 시스템의 임피던스 정합을 위해서 안쪽으로 돌출된 탭을 가지는데, 탭의 형태는 잘려진 타원형이다. 제안된 포물형 반사판 안테나의 반사판의 직경은 400 mm, 촛점은 134.23 mm 이며, 사용 중심주파수 16.5 GHz에서 안테나이득은 33.68 dBi, 3 dB 빔폭은 $3.3^{\circ}$, 반사손실 -15 dB 사용대역폭은 1.0 GHz 이상이 되도록 설계하여, HFSS-IE를 사용하여 검증하였다.

• Advances in pediatric surgery
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• 제13권2호
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• pp.144-154
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• 2007

Liver tumors in children are rare, relatively complex, and encompass a broad spectrum of disease processes. This study reviews our experience of liver tumors during the last 10 years. Medical records of 36 cases of liver tumors in children, treated at Samsung Medical Centers, from October 1994 to December 2005, were reviewed in this study. We analyzed disease characters and survival rates as a whole and by specific disease. The median age was 3.6 years. Male and female ratio was 1:1. The most common symptom was the palpable mass in 15 cases. Others were abdominal distension in 9 cases, jaundice in 2, vomiting in 2, weight loss in 2, and pubic hair growth in 1. CT or US and liver biopsy were performed for diagnosis. There were 28 malignant tumors: malignant rhabdoid tumor (1 case), hepatocellular carcinoma (3 cases), hemangioendothelioma type II (3 cases), angiosarcoma (1 case), and hepatoblastoma (20 cases). Eight tumors were benign; hepatic adenoma (1 case), focal nodular hyperplasia (2 cases), hemangioendothelioma type I (2 cases), mesenchymal hamartoma (3 cases). In this study the clinical characteristics were not different from the other reports. Liver transplantation was performed in 3 cases-1 with hepatoblastoma and 2 with hepatocelleular carcinoma. Accurate and early diagnosis, and individualized multimodality therapeutic approaches might be important for better outcome.

• Restorative Dentistry and Endodontics
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• 제25권2호
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• pp.289-298
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• 2000

Carbamide peroxide is usually used for vital teeth bleaching at home. Complications such as tooth hypersensitivity and/or gingival irritation are frequently reported. Therefore, this study was performed to evaluate any possible histological changes in pulp and periodontal tissue by carbamide peroxide bleaching gel in rats. 10% and 15% carbamide peroxide containing nightguard for upper molar were worn for 4 hours a day. The rats were sacrificed after 1 day, 2 days, 3 days, 4 days and 6 days application of carbamide peroxide respectively. The results were as follows : Mild infiltration of inflammatory changes below the junctional epithelium and hyperplasia of epithelium were observed in both 10% and 15% carbamide peroxide treated groups. In all experimental groups, odontoblasts were changed from columnar to cuboidal shape and/or obliterated and the focal loss of predentin was observed in pulp horn. With increasing time of application, these changes were more remarkable, but limited in pulp horn. Inflammatory reactions, vacuolar changes and hyaline degenerations of the pup tissue were also observed in some cases. These results suggested that carbamide peroxide gel used in home bleaching could cause reversible pulpal irritation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권12호
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• pp.3218-3241
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• 2023

Financial fraud undermines the sustainable development of financial markets. Financial statements can be regarded as the key source of information to obtain the operating conditions of listed companies. Current research focuses more on mining financial digital data instead of looking into text data. However, text data can reveal emotional information, which is an important basis for detecting financial fraud. The audit opinion of the financial statement is especially the fair opinion of a certified public accountant on the quality of enterprise financial reports. Therefore, this research was carried out by using the data features of 4,153 listed companies' financial annual reports and audits of text opinions in the past six years, and the paper puts forward a financial fraud detection model integrating audit opinions. First, the financial data index database and audit opinion text database were built. Second, digitized audit opinions with deep learning Bert model was employed. Finally, both the extracted audit numerical characteristics and the financial numerical indicators were used as the training data of the LightGBM model. What is worth paying attention to is that the imbalanced distribution of sample labels is also one of the focuses of financial fraud research. To solve this problem, data enhancement and Focal Loss feature learning functions were used in data processing and model training respectively. The experimental results show that compared with the conventional financial fraud detection model, the performance of the proposed model is improved greatly, with Area Under the Curve (AUC) and Accuracy reaching 81.42% and 78.15%, respectively.

• International Journal of Oral Biology
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• 제32권1호
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• pp.35-43
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• 2007

Tooth loss in elderly is mainly caused by alveolar bone loss via severe periodontitis. Although the severity of periodontitis is known to be affected by age, the aging process or the genetic changes during the aging of periodontal tissue cells are not well characterized. In this study, we investigated the effect of in vitro aging on the change of gene expression pattern in periodontal fibroblasts. Gingival fibroblasts (GF) and periodontal ligament fibroblasts (PDL) were obtained from two young patients and replicative senescence was induced by sequential subcultivation. When more than 90% cells were positively stained with senescence-associated ${\beta},-galactosidase$, those cells were regarded as aged cells. In aged GF and PDL, the level of phosphorylated retinoblastoma (RB) and $p16^{INK4A}$ protein was significantly decreased and increased, respectively. However, the protein level of p53 and p21, well known senescence-inducing genes, did not increase in aged GF and PDL. Although $p27^{Kip1}$ and $p15^{INK4B}$, another cyclin-dependent kinase inhibitors, were reported to be involved in replicative senescence of human cells, they were decreased in aged GF and PDL. Because senescent cells showed flattened and enlarged cell shape and are known to have increased focal adhesion, we examined the protein level of several integrins. Aged GF and PDL showed increased protein level of integrin ${\alpha}2$, ${\alpha}v$, and ${\beta}1$. When the gene expression profiles of actively proliferating young cells and aged cells were compared by cDNA microarray of 3,063 genes and were confirmed by reverse transcription-polymerase chain reaction, 7 genes and 15 genes were significantly and commonly increased and decreased, respectively, in aged GF and PDL. Among them, included are the genes that were known to be involved in the regulation of cell cycle, gene transcription, or integrin signaling. The change of gene expression pattern in GF and PDL was minimally similar to that of oral keratinocyte. These results suggest that $p16^{INK4A}/RB$ might be involved in replicative senescence of periodontal fibroblasts and the change of gene expression profile during aging process is cell type specific.

• 한국음향학회지
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• 제30권4호
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• pp.215-222
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• 2011

높은 분해능의 영상을 얻는데 사용하기 위하여 초고주파 대역에서 동작하는 집속 초음파 트랜스듀서를 제작하고 그 특성을 평가하였다. 그 트랜스듀서는 한쪽 면에만 접지용 전극이 있는 두께 9 ${\mu}m$의 PVDF 압전막의 다른 쪽 면에 CCP (Copper Clad Polyimide)막을 에폭시로 접착한 후, 금속구로 압착함에 의해 구각형을 형성시키고, 그 뒷면에 에폭시를 채워 몰딩 시키는 방법에 의해 만들어졌다. 제작된 곡률반경 7.5 mm, f-number 1.7의 트랜스듀서는 초점에 있는 표적에 대한 펄스에 코 측정결과 35.0 MHz의 대역폭을 가지며, 약 40 MHz인 피크주파수 부근에서의 삽입손실은 약 60 dB 을 나타내었는데, 그 측정결과는 에폭시 접착층의 두께를 고려한 KLM 등가회로 해석에 의한 시뮬레이션 결과와 유사한 것이었다. 나아가, 그 트랜스듀서에 의해 얻어진 가는 구리선 표적에 대한 영상을 35 MHz 트랜스듀서를 장착한 UBM (Ultrasonic Backscattering Microscope) 장치에 의한 영상과 비교한 결과, 측방향 분해능은 떨어지나 축방향 분해능은 다소 향상됨을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.6871-6876
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• 2015

Background: The meningeal hemangiopericytoma (MHPC) is a vascular tumor arising from pericytes. Most intracranial MHPCs resemble meningiomas (MNGs) in their clinical presentation and histological features and may therefore be misdiagnosed, despite important differences in prognosis. Materials and Methods: We report 8 cases of MHPC and 5 cases of MNG collected from 2007 to 2011 from the Neuro-Surgery and Histopathology departments. All 13 samples were re reviewed by two independent pathologists and investigated by immunohistochemistry (IHC) using mesenchymal, epithelial and neuro-glial markers. Additionally, we screened all tumors for a large panel of chromosomal alterations using multiplex ligation probe amplification (MLPA). Presence of the NAB2-STAT6 fusion gene was inferred by immunohistochemical staining for STAT6. Results: Compared with MNG, MHPCs showed strong VIM (100% of cases), CD99 (62%), bcl-2 (87%), and p16 (75%) staining but only focal positivity with EMA (33%) and NSE (37%). The p21 antibody was positive in 62% of MHPC and less than 1% in all MNGs. MLPA data did not distinguish HPC from MNG, with PTEN loss and ERBB2 gain found in both. By contrast, STAT6 nuclear staining was observed in 3 MHPC cases and was absent from MNG. Conclusions: MNG and MHPC comprise a spectrum of tumors that cannot be easily differentiated based on histopathology. The presence of STAT6 nuclear positivity may however be a useful diagnostic marker.

• 대한한의학회지
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• 제26권2호
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• pp.77-84
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• 2005

Objectives: Chunghyul-dan is a combinatorial herbal medicine, and previous studies reported it had therapeutic effects for microangiopathy, which is a major part. in the progression of stroke, as well as having anti-hypertensive, anti-hyperlipidemic, anti-apoptotic, anti-oxidative, and anti-inflammatory activities, Therefore, we examined the inhibitory effect of Chunghyul-dan on stroke occurrence in patients with silent brain infarction. Methods: We prescribed Chunghyul-dan at 600 mg a day to patients with silent brain infarction confirmed by brain MRI, and monitored stroke occurrence, drug compliances, and adverse effects for 1 year, We then performed follow-up brain MRI to detect new vascular lesions after 1 year of Chunghyul-dan medication. As for the subjects lost to follow-up, we assessed their prognosis after 1 year by telephone. Results: There were twenty-one subjects who were treated with Chunghyul-dan for more than 1 year, None of them experienced new clinical syndromes characterized by rapidly developing clinical symptoms and signs of focal and at times global loss of brain function, which could be accompanied with evidence of stroke occurrence, or any adverse effects during the Chunghyul-dan medication period. These results might be explained by various biochemical effects of Chunghyul-dan on microangiopathy, which is closely related with cell cycle progression, hypertension, hyperlipidemia, vascular inflammation, and oxidative damage. Of the 10 subjects lost to follow-up, six were reached; two of them had stroke occurrence. Conclusions: We suggest Chunghyul-dan could be useful for prevention of stroke occurrence in patients with silent brain infarction by preventing the progression of microangiopathy. Further study with a randomized controlled trial is needed to confirm this suggestion.

• Journal of Korean Neurosurgical Society
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• 제29권9호
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• pp.1233-1237
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• 2000

Objectives : In order to evaluate the metabolic changes associated with pericontusional edematous area in mild head injury, proton magnetic resonance spectroscopy(1H-MRS) was performed in mild head injury patients (initial GCS score 13-15) with focal brain contusion. Methods : Seven head injury patients with initial GCS 13-15(3 males and 4 females : age range 15-65 years, mean age 33 years) have underwent 1H-MRS evaluations. The patients were examined within 7 days after injury(n=7) and 2 months after injury(n=5). The region of interest(ROI) was selected in the edematous area adjacent to traumatic brain contusion upon T2-weighted MR images and a corresponding region of the contralateral hemisphere (ROC, region of contralateral corresponding hemisphere) was examined as well. The metabolic ratios of NAA/Cr and lactate/Cr were compared between ROIs, ROCs and control values. Results : In initial NAA/Cr ratios, the values of ROIs were significantly lower than those of the controls(p=0.009), but there was no difference either between ROIs and ROCs(p=0.410) or between ROCs of patients and the control (p=0.199). In lactate/Cr ratios, the ROIs in all seven patients and the ROCs in two showed increased lactate signals. The lactate/Cr ratios of the ROIs were significantly elevated as compared to those of the ROCs(p=0.02) and the control(p=0.015). In two months follow-up, lactate signals were absent or significantly reduced(p=0.015). In no patients, clinical or radiological deterioration has been observed. Conclusion : Our 1H-MRS results demonstrate that there are significant ischemic changes in pericontusional edematous areas as indicated by elevated lactate signals in the patients with mild head injury. But there were no consistent neural loss or dysfunction in these area. There findings suggest that pericontusional edematous areas can be vulnerable to secondary brain insults even in the patients with mild head injury.