• Title/Summary/Keyword: false negative

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Comparative evaluation of two commercial ELISA kits for detection of PRRS antibodies using sera collected from pigs in various stages of PRRSV infection (다양한 PRRSV 감염상태에 있는 돼지 혈청을 이용한 PRRS 항체 ELISA 키트들의 비교 평가)

  • Seo, Byoung-Joo;Kim, Hyoun-Il;Kim, Won-Il
    • Korean Journal of Veterinary Service
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    • v.37 no.3
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    • pp.151-156
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    • 2014
  • Porcine reproductive and respiratory syndrome virus (PRRSV) causes major economic losses to the Korean pig industry. ELISA tests using recombinant nucleocapsid protein of PRRSV have been most commonly used for PRRS diagnostics. In the current study, two commercial PRRSV ELISA kits (Bionote PRRSV Antibody ELISA and IDEXX 3XR PRRS Antibody ELISA) have been compared using sera collected from 19 swine farms in various stages of PRRSV infection confirmed by professional diagnostic centers. Thus 130 sera collected from 5 different farms with active PRRSV infection, 130 sera from 6 different farms with PRRS-stabilized status, and 140 sera from 8 different farms with PRRS-free status were evaluated to determine the correlation of test results between those ELISA kits. Both ELISA kits showed a good correlation [PRRSV-positive farms ($R^2$=0.6375) and stabilized farms ($R^2$=0.8928)] in sample-to-positive (S/P) ratio va lues. Among the 140 sera from negative farms, one sample was falsely positive by either of the ELISA kits. In conclusion, both of the ELISA kits showed a good correlation when applied on field samples collected from farms at various stages of PRRSV infection. Bionote ELISA or IDEXX ELISA gave a false positive result on 1 out of 140 negative samples so their specificity was calculated as 99.3%. Therefore, Bionote ELISA would be a good complementary and alternative method for IDEXX ELISA kit, and vice versa.

Sequential use of real-time polymerase chain reaction and enzyme-linked immunosorbent assay techniques verifies adulteration of fermented sausages with chicken meat

  • Benli, Hakan;Barutcu, Elif
    • Animal Bioscience
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    • v.34 no.12
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    • pp.1995-2002
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    • 2021
  • Objective: Detection of adulteration in processed meats is an important issue for some countries due to substitution of beef with a cheaper source of protein like poultry. In this study, the presence of chicken meat was investigated using real-time polymerase chain reaction (real-time PCR) and enzyme-linked immunosorbent assay (ELISA) techniques to verify adulteration of fermented sausage samples. Methods: A total of 60 commercial samples were collected from 20 establishments in three replicates including 10 fermented sausage manufacturers and 10 butchers to investigate the presence of chicken meat with the sequential use of real-time PCR and ELISA techniques. In addition, pH, moisture content, water activity and color values of the samples were determined. Results: Both real-time PCR and ELISA showed agreement on the presence or absence of chicken meat in 55 out of 60 fermented sausage samples and chicken meat was identified with both methods in 16 samples. Five samples produced inconsistent results for the presence of chicken meat in the first run. Nevertheless, the presence of chicken meat was verified with both methods when these samples were analyzed for the second time. In addition, the average physico-chemical values of the fermented sausage samples tested positive for chicken meat were not significantly different from some of those fermented sausage samples tested negative for the chicken meat. Conclusion: The sequential use of real-time PCR and ELISA techniques in fermented sausages could be beneficial for the government testing programs to eliminate false negatives for detection of adulteration with chicken meat. Furthermore, consumers should not rely on some of the quality cues including color to predict the adulteration of fermented sausages with chicken meat since there were no statistical differences among some of the samples tested positive and negative for chicken meat.

A study on consumer confusion, value, and price sensitivity of eco-friendly fashion product (친환경 패션제품에 대한 소비자 혼란과 가치, 가격민감성 연구)

  • Shin, Sangmoo;Lim, Yura
    • The Research Journal of the Costume Culture
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    • v.29 no.1
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    • pp.48-64
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    • 2021
  • Eco-friendly consumption is a prominent trend in the fashion industry, by which many firms attract the interest of consumers using a green marketing strategy. However, "greenwashing" (caused by distorted, exaggerated, and false information) gives rise to consumer confusion. The purpose of this study is to investigate the effect of consumer confusion and value on price sensitivity and purchase intention. Data was collected from 228 respondents using a questionnaire that was distributed to consumers living in Seoul and Kyunggi, South Korea. The data was analyzed by factor analysis, regression analysis, and Cronbach's alpha using SPSS 23.0. The results were as follows: First, factor analysis showed the consumer value variable was significantly categorized in altruistic and self-expressive values. All variables (altruism, selfexpression, consumer confusion, price sensitivity, and purchase intention) were shown to have significantly good internal validity. Second, altruistic consumer value was shown to positively affect the purchase intention of eco-friendly fashion products, but self-expressive consumer value had no significant effect. Third, consumer confusion on eco-friendly fashion products had a negative effect on purchase intention. Fourth, altruistic and self-expressive consumer values had no effect on price sensitivity. Fifth, consumer confusion on eco-friendly fashion products positively affect price sensitivity. Sixth, price sensitivity on eco-friendly fashion products had a negative effect on purchase intention. Therefore, fashion firms should provide a certified green mark to consumers to eliminate confusion and deliver the right message without greenwashing. Moreover, fashion firms should develop green marketing strategies that are more focused on altruistic consumers.

Detection of Anomaly VMS Messages Using Bi-Directional GPT Networks (양방향 GPT 네트워크를 이용한 VMS 메시지 이상 탐지)

  • Choi, Hyo Rim;Park, Seungyoung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.4
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    • pp.125-144
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    • 2022
  • When a variable message signs (VMS) system displays false information related to traffic safety caused by malicious attacks, it could pose a serious risk to drivers. If the normal message patterns displayed on the VMS system are learned, it would be possible to detect and respond to the anomalous messages quickly. This paper proposes a method for detecting anomalous messages by learning the normal patterns of messages using a bi-directional generative pre-trained transformer (GPT) network. In particular, the proposed method was trained using the normal messages and their system parameters to minimize the corresponding negative log-likelihood (NLL) values. After adequate training, the proposed method could detect an anomalous message when its NLL value was larger than a pre-specified threshold value. The experiment results showed that the proposed method could detect malicious messages and cases when the system error occurs.

Diagnostic Role of Tc-99m MIBI Scintimammography in Suspected Breast Cancer Patients: Results of Unicenter Trial (유방암이 의심되는 환자에서 Tc-99m MIBI 유방스캔의 진단적 역할: 단일기관의 결과)

  • Kim, Seong-Jang;Kim, In-Ju;Kim, Yong-Ki;Bae, Young-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.3
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    • pp.234-242
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    • 2000
  • Purpose: Tc-99m MIBI scintimammography has been validated as an useful non-invasive diagnostic tool for the primary breast cancer. But most studies have included small population of patients. We have experienced a large study population and investigated the diagnostic usefulness of Tc-99m MIBI scintimammography in detection of primary breast cancer and axillary lymph node metastasis. Materials and Methods: This study included 305 patients who underwent scintimammogtaphy for palpable breast masses or abnormal radiologic findings. Tc-99m MIBI scintimammography was performed 10 minutes after intravenous injection of 925 MBq of Tc-99m MIBI. If the early image revealed abnormal finding, 3 hour delayed image was also acquired. We calculated early and delayed lesion to non-lesion ratios (L/N). The pathologic diagnosis was obtained from surgical operation or FNAB and compared with the results of Tc-99m MIBI scintimammography. Results: Malignant breast diseases were 155 and benign ones were 150. Tc-99m MIBI scintimammography revealed 132 true positive, 23 false negative, 10 false positive, and 140 true negative cases. The sensitivity, specificity, positive predictive value and negative predictive value for the primary breast cancer detection were 85.2%, 93.4%, 92.9%, and 85.9%, respectively. The sensitivity, specificity, positive predictive and negative predictive values of Tc-99m MIBI scintimammography in detecting metastatic axillary lymph node involvement were 22%, 90.4%, 61.9% and 62.3%, respectively. Early L/N of malignant breast disease was significantly higher than that of benign one ($2.44{\pm}0.97\;vs\;1.94{\pm}0.78$, p=0.01). Delayed L/N had no significant difference between malignant and benign breast diseases ($1.94{\pm}0.52\;vs\;1.91{\pm}0.73$, p=0.43). Conclusion: Our study revealed that Tc-99m MIBI scintimammography was an useful diagnostic tool for the diagnosis of breast cancer. And early L/N ratio might provide complementary role in the detection of breast cancer. But the Tc-99m MIBI scintimammography had limited value in the detection of small breast cancer (less than 1 cm) and axillary lymph node metastasis.

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Comparison of the Results for Sentinel Lymph Node Mapping in the Breast Cancer Patients using $^{99m}Tc$-Antimony Trisulfide Colloid, $^{99m}Tc$-Tin Colloid, and $^{99m}Tc$-Human Serum Albumin (유방암 환자에서 $^{99m}Tc$-Antimony Trisulfide Colloid, $^{99m}Tc$-Tin Colloid, $^{99m}Tc$-Human Serum Albumin을 이용한 감시림프절 매핑 성적의 비교)

  • Jang, Sung-June;Moon, Seung-Hwan;Kim, Seok-Ki;Kim, Bom-Sahn;Kim, Seok-Won;Chung, Ki-Wook;Kang, Keon-Wook;Lee, Eun-Sook
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.6
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    • pp.546-552
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    • 2007
  • Purpose: In the breast cancer patient, lymphatic mapping and sentinel lymph node biopsy are the most important procedure for axillary lymph node staging. We aimed to compare the three radiocolloids [$^{99m}Tc$-antimony trisulfide colloid (ASC), $^{99m}Tc$-tin colloid (TC), and $^{99m}Tc$-human serum albumin (HSA)] for sentinel lymph node mapping. Subjects and Methods: Totally, 397 patients with clinically N0 stage were enrolled. $^{99m}Tc$-ASC was injected in 202 out of 397 patients, $^{99m}Tc$-TC was injected in 120 patients, and $^{99m}Tc$-HSA was injected in the remaining 75 patients. The sentinel lymph nodes were localized by lymphoscintigraphy and selected using intraoperative gamma probe. All sentinel lymph nodes were investigated by intraoperative pathologic consultation. The axillary lymph nodes which were harvested by the lymph node dissection were also investigated. Results: The patients of each group showed similar clinical characteristics. There were no significant differences (p>0.05) in the identification rate of sentinel lymph nodes (IR), false negative rate (FNR), and negative predictive value (NPV). The axillary lymphadenectomy revealed axillary lymph node metastases in those three groups (ASC-33.2%, TC-31.7%, HSA-22.7%). The IR, FNR, and NPV were not significantly different among those groups. Conclusion: Those three $^{99m}Tc$-labeled radiocolloids showed equivalent results in sentinel lymph node mapping of breast cancer.

The Role of Camera-Based Coincidence Positron Emission Tomography in Nodal Staging of Non-Small Cell Lung Cancer (비소세포폐암의 림프절 병기 결정에서 Coincidence PET의 역할)

  • Lee, Sun-Min;Choi, Young-Hwa;Oh, Yoon-Jung;Cheong, Seong-Cheoll;Park, Kwang-Joo;Hwang, Sung-Chul;Lee, Yi-Hyeong;Park, Chan-H;Hahn, Myung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.47 no.5
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    • pp.642-649
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    • 1999
  • Background: It is very important to determine an accurate staging of the non-small cell lung cancer(NSCLC) for an assessment of operability and it's prognosis. However, it is difficult to evaluate tumor involvement of mediastinal lymph nodes accurately utilizing noninvasive imaging modalities. PET is one of the sensitive and specific imaging modality. Unfortunately PET is limited use because of prohibitive cost involved with it's operation. Recently hybrid SPECT/PET(single photon emission computed tomography/positron emission tomography) camera based PET imaging was introduced with relatively low cost. We evaluated the usefulness of coincidence detection(CoDe) PET in the detection of metastasis to the mediastinal lymph nodes in patients with NSCLC. Methods: Twenty one patients with NSCLC were evaluated by CT or MRI and they were considered operable. CoDe PET was performed in all 21 patients prior to surgery. Tomographic slices of axial, coronal and sagittal planes were visually analysed. At surgery, mediastinal lymph nodes were removed and histological diagnosis was performed. CoDe PET findings were correlated with histological findings. Results: Twenty of 21 primary tumor masses were detected by the CoDe PET. Thirteen of 21 patients was correctly diagnosed mediastinal lymph node metastasis by the CoDe PET. Pathological N0 was 14 cases and the specificity of N0 of CoDe PET was 64.3%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of N1 node was 83.3%, 73.3%, 55.6%, 91.7%, and 76.2% respectively. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of N2 node was 60.0%, 87.5%, 60.0%,87.5%, and 90.0% respectively. There were 3 false negative cases but the size of the 3 nodes were less than 1cm. The size of true positive nodes were 1.1cm, 1.0cm, 0.5cm respectively. There were 1 false positive among the 12 lymph nodes which were larger than 1cm. False positive cases consisted of 1 tuberculosis case, 1 pneumoconiosis case and 1 anthracosis case. Conclusion: CoDe PET has relatively high negative predictive value in the enlarged lymph node in staging of mediastinal nodes in patients with NSCLC. Therefore CoDe PET is useful in ruling out metastasis of enlarged N3 nodes. However, further study is needed including more number of patients in the future.

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Use of Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Patients with Axillary Node-Positive Breast Cancer in Diagnosis

  • Choi, Hee Jun;Kim, Isaac;Alsharif, Emad;Park, Sungmin;Kim, Jae-Myung;Ryu, Jai Min;Nam, Seok Jin;Kim, Seok Won;Yu, Jonghan;Lee, Se Kyung;Lee, Jeong Eon
    • Journal of Breast Cancer
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    • v.21 no.4
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    • pp.433-4341
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    • 2018
  • Purpose: This study aimed to evaluate the effects of sentinel lymph node biopsy (SLNB) on recurrence and survival after neoadjuvant chemotherapy (NAC) in breast cancer patients with cytology-proven axillary node metastasis. Methods: We selected patients who were diagnosed with invasive breast cancer and axillary lymph node metastasis and were treated with NAC followed by curative surgery between January 2007 and December 2014. We classified patients into three groups: group A, negative sentinel lymph node (SLN) status and no further dissection; group B, negative SLN status with backup axillary lymph node dissection (ALND); and group C, no residual axillary metastasis on pathology with standard ALND. Results: The median follow-up time was 51 months (range, 3-122 months) and the median number of retrieved SLNs was 5 (range, 2-9). The SLN identification rate was 98.3% (234/238 patients), and the false negative rate of SLNB after NAC was 7.5%. There was no significant difference in axillary recurrence-free survival (p=0.118), disease-free survival (DFS; p=0.578) or overall survival (OS; p=0.149) among groups A, B, and C. In the subgroup analysis of breast pathologic complete response (pCR) status, there was no significant difference in DFS (p=0.271, p=0.892) or OS (p=0.207, p=0.300) in the breast pCR and non-pCR patients. Conclusion: These results suggest that SLNB can be feasible and oncologically safe after NAC for cytology-determined axillary node metastasis patients and could help reduce arm morbidity and lymphedema by avoiding ALND in SLN-negative patients.

A Systems Thinking Approach to the Enhancement of Social Capital: In Case of Social Media Users (시스템 사고 접근을 통한 사회적 자본 증대 방안 연구: 소셜미디어 사용자를 중심으로)

  • Son, Jung-Eun;Jang, Yoon-Jung;Lee, So-Hyun;Kim, Hee-Woong
    • Information Systems Review
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    • v.15 no.2
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    • pp.21-40
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    • 2013
  • Because of the recent development of information technology, especially the popularization of social media, false rumors and abusive comments on social media have increased, which has accelerated conflicts in online society. Since these conflicts lead to significant negative influences on online society, it is important to figure out how to cope with the conflicts and integrate the society. Thus, this study provides effective political implications that will advance the society where people can communicate based on trust in social media. In addition, we suggest new sociocultural change phenomenon and social integration by drawing the Causal Loop Diagram focusing on the dimension of social capital in social media environment.

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Improving Performance of Crimp Signal Analysis by Falling Edge Alignment and Parameter Error Estimation in CFM (CFM에서 하강 에지 정렬과 파라미터 에러 평가에 의한 크림프 시그널 분석 성능 향상)

  • Aurecianus, Steven;Kang, Taesam;Han, Chung Gwon;Park, Jungkeun
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.9
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    • pp.686-692
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    • 2016
  • A Crimp Force Monitor (CFM) is equipment for detecting crimp errors by analyzing crimp signals obtained from force and strain sensors. The analysis is commonly performed by aligning a measured crimp signal with a reference signal and comparing their difference. Current analysis methods often suffer from wrong alignments that result in false negative detections. This paper presents a new crimp signal analysis method in CFM. First, a falling edge alignment is proposed that matches falling edges of the measured and the reference signals by minimizing the absolute difference summation. Second, a signal parameter error is introduced to evaluate the crimp quality difference between the measured signal and the reference. For calculating the signal parameter error, part of a signal is identified and divided into several regions to maximize the signal parameter errors. Experiments showed that the proposed method can improve the signal alignment and accurately detect bad crimps especially with the strain sensor.