• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제18권2호
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• pp.77-105
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• 2014

Medical imaging techniques have evolved to expand our ability to visualize new contrast information of electrical, optical, and mechanical properties of tissues in the human body using noninvasive measurement methods. In particular, electrical tissue property imaging techniques have received considerable attention for the last few decades since electrical properties of biological tissues and organs change with their physiological functions and pathological states. We can express the electrical tissue properties as the frequency-dependent admittivity, which can be measured in a macroscopic scale by assessing the relation between the time-harmonic electric field and current density. The main issue is to reconstruct spectroscopic admittivity images from 10 Hz to 1 MHz, for example, with reasonably high spatial and temporal resolutions. It requires a solution of a nonlinear inverse problem involving Maxwell's equations. To solve the inverse problem with practical significance, we need deep knowledge on its mathematical formulation of underlying physical phenomena, implementation of image reconstruction algorithms, and practical limitations associated with the measurement sensitivity, specificity, noise, and data acquisition time. This paper discusses a number of issues in electrical tissue property imaging modalities and their future directions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권10호
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• pp.2788-2808
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• 2023

Brain tumors are one of the most threatening malignancies for humans. Misdiagnosis of brain tumors can result in false medical intervention, which ultimately reduces a patient's chance of survival. Manual identification and segmentation of brain tumors from Magnetic Resonance Imaging (MRI) scans can be difficult and error-prone because of the great range of tumor tissues that exist in various individuals and the similarity of normal tissues. To overcome this limitation, the Amended Convolutional Neural Network (ACNN) model has been introduced, a unique combination of three techniques that have not been previously explored for brain tumor detection. The three techniques integrated into the ACNN model are image tissue preprocessing using the Kalman Bucy Smoothing Filter to remove noisy pixels from the input, image tissue segmentation using the Isotonic Regressive Image Tissue Segmentation Process, and feature extraction using the Marr Wavelet Transformation. The extracted features are compared with the testing features using a sigmoid activation function in the output layer. The experimental findings show that the suggested model outperforms existing techniques concerning accuracy, precision, sensitivity, dice score, Jaccard index, specificity, Positive Predictive Value, Hausdorff distance, recall, and F1 score. The proposed ACNN model achieved a maximum accuracy of 98.8%, which is higher than other existing models, according to the experimental results.

• 대한방사선기술학회지:방사선기술과학
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• 제41권4호
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• pp.305-312
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• 2018

The incidence of cardiovascular disease increases rapidly after 40's. The thickness of the epicardial adipose tissue was measured to analyze the risk factors affecting the thickness change. We present the cut off value for the epicardial adipose tissue thickness for high impacted variables. For the study, 547 patients underwent echocardiography, epicardial adipose tissue thickness, body mass index, abdominal subcutaneous fat thickness and diabetes mellitus were used as analytical variables. As a result, multiple regression analysis of age group showed that diabetes mellitus was highly influential in all age group, so we could predict the cut off value for the epicardial adipose tissue thickness for diabetes mellitus. As a result of ROC curve analysis, cut off value of 7.44 mm was obtained with sensitivity of 79.6% and specificity of 60.6% for diab etes variab le. Logistic regression analysis b ased on this value showed that the risk for diab etes increased 6 times with each increase in the thickness of the epicardial adipose tissue. Among the various obesity indexes, epicardial adipose tissue is used as an important index especially to prevent the risk of cardiovascular disease. Therefore, we suggest that the use of echocardiography as a routine screening method for the prevention of cardiovascular disease and metabolic syndrome, which is rapidly increasing in patients over 40's age, will enable more effective monitoring. Radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.

• 대한임상검사과학회지
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• 제55권1호
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• pp.45-51
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• 2023

개 파보바이러스(canine parvovirus type 2, CPV-2)와 코로나바이러스(canine coronavirus, CCoV)는 개에서 위장관염을 일으키는 주요 병원체이다. 두 바이러스는 전염성과 이환율이 높고 특정한 치료법이 없어 신속 정확한 진단이 필요하다. 동물용 신속진단키트 (rapid diagnostic test, RDT)는 빠르고, 간편하여 진료현장에서 널리 활용되고 있다. 이에 본 연구에서는 성능평가를 통해 CPV-2/CCoV RDT의 임상적 유용성을 확인하고자 하였다. 성능평가 항목으로 최소검출한계(limit of detection, LoD), 교차반응, 간섭, 민감도, 특이도, 음성우도비(negative likelihood ratio, NLR), 카파통계량(kappa value, κ) 등을 확인하였다. 성능평가 결과, LoD는 CPV-2 9.7×10 50% tissue culture infections dose (TCID₅₀)/mL, CCoV 2.5×10² TCID₅₀/mL로 나타났다. 병원체 9종에 의한 교차반응과 간섭물질에 대한 간섭은 관찰되지 않았다. RDT는 두 바이러스의 검출에 있어 민감도 90.0%, 특이도 100.0%, NLR=0.1, κ=0.90으로 나타났다. 결론적으로 CPV-2/CCoV RDT는 높은 민감도, 특이도, κ와 낮은 NLR을 보여 선별검사로써 유용할 것으로 생각된다.

• Journal of Korean Neurosurgical Society
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• 제64권3호
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• pp.418-426
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• 2021

Objective : A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not well-understood. This study evaluates the effectiveness of DWI in the diagnosis of CVT. Methods : Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue. Results : Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference-0.33×10-3 ㎟/s [95% CI, -0.44 to -0.23]; p<0.00001). Conclusion : DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

• 대한골관절종양학회지
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• 제11권1호
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• pp.32-39
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• 2005

목적: 최근에는 연부 종양의 진단에 FDG-PET을 이용하기 위한 연구가 다양하게 이루어지고 있다. 그러나, 그 임상적 유용성에 대해서는 알려져 있지 않다. 이 연구의 목적은 기존의 진단법과 비교하여 FDG-PET의 유용성을 평가하는 데 있다. 대상 및 방법: 연구 대상은 2001년 3월에서 2002년 3월 사이에 연부 조직 종양으로 진단받은 29명의 환자(남자 16명, 여자 13명, 평균 47세)를 대상으로 하였다. 모든 환자군에서 기존의 검사법과 FDG-PET을 시행하였다. 타당성 검증에서 국소 병변은 모든 경우 조직검사로 판단하였고, 전이 병변은 조직 검사와 6개월 간의 추시 결과로 판단하였다. 각각의 진단은 독립적으로 시행되었으며, 진단의 정확도와 누적 비용-정확도율을 측정하였다. 결과: 국소 병변의 진단에서 MRI와 FDG-PET의 민감도, 특이도, 정확도는 각각 91%, 57%, 83% 와 95%, 43%, 83%이었다. 원격 전이의 진단에서 기존의 검사법과 FDG-PET의 민감도, 특이도, 정확도는 각각 77%, 89%, 87% 와 92%, 94%, 93%이었다. 누적 비용-정확도율은 145,000원/% 이었다. 종양의 등급별 민감도 분석에서 고등급의 종양이 가장 비용-효용성이 높았다. 결론: 국소부위의 재발과 잔존 종양의 진단에서 FDG-PET의 정확도는 MRI와 차이가 없었다. 반면, 원격 전이의 진단은 FDG-PET이 기존의 검사 보다 정확하였다. 고등급 종양의 경우 저등급 종양보다 FDG-PET의 유용성이 큰 것을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1339-1344
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• 2014

Aims: Alterations in mitochondrial DNA (mtDNA) have been implicated in carcinogenesis and tumor progression. We here evaluated the diagnostic and prognostic potential of mtDNA as a biomarker for breast cancer. Methods: Using multiplex real-time polymerase chain reaction, nuclear DNA (nDNA) and mtDNA levels in serum, buffy coat, tumor, and tumor-adjacent tissue samples from 50 breast cancer patients were determined and assessed for associations with clinicopathological features. To evaluate mtDNA as a biomarker for distinguishing between the four sample types, we created receiver operating characteristic (ROC) curves. Results: The mtDNA levels in buffy coat were significantly lower than in other sample types. Relative to tumor-adjacent tissue, reduced levels of mtDNA were identified in buffy coat and tumor tissue but not in serum. According to ROC curve analysis, mtDNA levels could be used to distinguish between buffy coat and tumor-adjacent tissue samples with good sensitivity (77%) and specificity (83%). Moreover, mtDNA levels in serum and tumor tissue were positively associated with cancer TMN stage. Conclusions: The mtDNA levels in blood samples may represent a promising, non-invasive biomarker in breast cancer patients. Additional, large-scale validation studies are required to establish the potential use of mtDNA levels in the early diagnosis and monitoring of breast cancer.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.143-143
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• 2003

The matrix metalloproteases (MMPs) play important roles in invasion, metastasis and angiogenesis in various cell types. An endogenous inhibitor of MMP, tissue inhibitor of metalloprotease-2 (TIMP-2), has high specificity for MMP-2. An imbalance between MMP-2 and TIMP-2 causes the degradation of the extracellular matrix associated with pathological events including invasion, metastasis and angiogenesis.(omitted)

• Journal of Plant Biology
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• 제39권2호
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• pp.99-105
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• 1996

Immunocytochemistry utilizes the specificity of the antigen-antibody reaction to localize specific antigens in cells or cellular organelles. Here we report the use of monoclonal antibodies, in conjunction with gold-labeled second antibodies to study the ultrastructural localization and tissue distribution of the Mr 98, 000 anionic peroxidase and other wall antigens. The antibody specific for this wall peroxidase, mWP3, labeled mainly the cell wall area. At the tissue level, the Mr 98, 000 peroxidase is located predominantly in the leaf mesophyll, internal coleoptile and sieve elements, but not in the root, as assayed with these procedures. The coleoptile walls were less heavily stained than the walls of leaf mesophyll cells. At the subcellular level, it is localized mainly in intercellular regions of the cell walls. A similar staining pattern was revealed by mWP19, one of anti-$\beta$ glucosidase antibody, though it looked less heavily stained than one with mWP3. In order to serve as a control wall staining using IgM monoclonal antibodies, mWP18 was used. Most of the label is localized over wall regions of cells of the young leaf mesophyll and coleoptile.

• Asian-Australasian Journal of Animal Sciences
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• 제25권5호
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• pp.733-737
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• 2012

Determination of sex origin of cattle meat by fast and reliable molecular methods is an important measure to ensure correct allocation of export refunds particularly in European countries and also female cattle (cow) slaughter is legally banned in India because of religious beliefs. Based on the DEAD box protein gene located on the X and Y chromosomes, 2 pair of primers were designed and the system of PCR was optimized. Upon PCR amplification, male tissue showed 2 bands, while female tissue resulted in only one band. The accuracy and specificity of the primers was assessed using DNA template extracted from cattle meat of known sex. The protocol was subjected to a blind test and showed 100% concordance, proving its accuracy and reliability.