• Title/Summary/Keyword: false negative

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Evaluation for detection of Cryptosporidium oocysts in diarrheal feces of calves (야외 송아지 설사변에서 작은와포자충 검출에 대한 평가)

  • Wi, Seong-Hwan;Ju, Hu-Don;Gang, Yeong-Bae
    • Parasites, Hosts and Diseases
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    • v.34 no.2
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    • pp.121-126
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    • 1996
  • For the detection of Cwptospori,mum oocysts, fecal samples were collected from 201 calves which showed diarrhea. Among the 201 samples, 29 samples (14.4%) were positive for Cwptosporinium spry. by the DMSO-modified acid-fast stain (MAFS) , 23 samples (11.4%) were positive by commercial kit (Meridian Diagnostics, Cincinnati, Ohiol and 23 by the indirect immunofluorescence antibody (IFA )assay employing the monoclonal antibody (mAb C6). When tested by both IFA and MAFS, 20 fecal samples were positive for Cwptosporinium oocysts whereas 169 fecal samples were negative. If the MAFS is considered a standard method for oocyst detection, the IFA showed 69% of sensitivity and 98% of specificity. When tested by both IFA and commercial kit, 22 fecal samples were positive for Cwptospori,mum oocysts while 177 samples were negative. One sample tested by IFA was found to be false negative, when compared with the results by commercial kit. The sensitivity of IFA was calculated as high as 96%; the specificity as 99% and the predictive value was also 99%. In the present study, IFA employing the nAb C6 revealed that 23 samples (11.4%) were positive among the 201 calves showing diarrhea. Of 23 IFA positive samples, 4 samples (5%) showed cryptosporidial oocysts more than 105 OPG Therefore. it is concluded that the calves showing cryptosporidial oocysts more than 105 OPG in the feces were highly associated with clinical cryptosporidiosis.

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Usefulness of FDG-PET/CT as a Diagnostic Tool for Routine Post Therapy Evaluation in Endometrial Cancer (자궁내막암의 치료 후 루틴 추적검사 방법으로서 FDG-PET/CT의 유용성)

  • Lee, Shin-Jae;Jeon, Tae-Joo;Kim, Seung-Jo;Kim, Hee-Jin;An, Hee-Jung
    • Nuclear Medicine and Molecular Imaging
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    • v.43 no.4
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    • pp.301-308
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    • 2009
  • Purpose: The aim of this study was to evaluate the usefulness of FDG-PET/CT as follow up imaging tool in patients with endometrial cancer after therapy. Material and Methods: One hundred one patients with endometrial cancer who underwent FDG PET/CT after the treatment of this disease were included in this study population (25-79 yr old, Mean age 50.6 yr old) and all these patients also performed various laboratory and imaging studies such as serum tumor marker, CT or MRI. The lesions having increased focal FDG uptake were classified into benign, equivocal, and malignant one according to their pattern and activity. Tumor recurrence was confirmed by histopathological results and other clinical and imaging data. Results: Among the 19 patients with 30 malignant or equivocal hot uptakes, 11 of 14 patients supposed to be malignant finding in PET/CT were proved to be tumor recurrence, while one of 5 patients with equivocal lesions were recurred malignancy, Two false negative cases were turned out to be peritoneal carcinomatosis, Estimated sensitivity, specificity and accuracy of PET/CT for diagnosis of recurrence in endometrial carcinoma after treatment were 86 %, 92 % and 91 %, respectively. Positive and negative predictive values in the same issue were 63% and 98%, respectively. Conclusion: FDG-PET/CT is useful for regular work up of endometrial carcinoma after the treatment because of its high negative predictive value as well as high sensitivity and specificity.

Monitoring of Commercial Red Pepper Powders for Their Irradiation Status (물리적 확인시험법을 이용한 시판 유통 중인 고춧가루의 방사선 조사여부 판별 모니터링)

  • Jeong, Mi-Seon;Ahn, Jae-Jun;Akram, Kashif;Kim, Gui-Ran;Kim, Hyun-Ku;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.44 no.6
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    • pp.673-679
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    • 2012
  • Ten commercially available red pepper powders were investigated using photostimulated-luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) analyses to confirm their irradiation status. The application of PSL, TL, and ESR analyses was also confirmed by in-house irradiation. In PSL-based screening, all samples gave negative photon counts (<700 PCs). The PSL calibration dose (1 kGy) showed a low sensitivity of 4 samples, while the others provided reliable screening results. TL glow curves demonstrated maximum peaks after $250^{\circ}C$ for the 6 samples; however 4 samples gave complex TL glow curves with maximum peaks in the range of $185-260^{\circ}C$ (radiation-specific), which could be the effect of an irradiated component in low concentration as the TL ratios of all samples were <0.1. Radiation-specific ESR features were absent in the all commercial samples. Variable irradiation detection properties were found; where the TL analysis showed the possible presence of an irradiated component in 4 samples requiring further monitoring and investigation.

The Effect of New Infectious Diseases Using Structural Equation on Dental Hygienist Image and Employment Recognition: Focused on Online Information (구조방정식을 이용한 신종 감염병이 치과위생사 이미지와 취업 인식에 미치는 영향: 온라인 정보 중심으로)

  • Son, Eun-Gyo;Jung, Hwa-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.231-239
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    • 2021
  • The purpose of this study was to understand how a dental hygienist is viewed by students in terms of both image and job /employment perception using structural equations. This together with the incorporation of available online information would help in collating the necessary data for ensuring adequate manpower of dental hygienists' in the future. The collected data were analyzed using SPSS Statistics 24.0 and AMOS Graphics 21.0 statistics packages. It was found that students who perceive employment positively have a positive image of a dental hygienist even if a new infectious disease were to occur. They appreciate that a negative image of a dental hygienist's job during an epidemic could cause a negative perception of employment as a dental hygienist. Those who think negatively of the internet as a source of information believe that the internet has a lot of false information, is harmful, promotes anxiety, and has been shown to promote negative perceptions about employment as a dental hygienist. Those who think positively of internet information think that dental hygienists are susceptible to infection and can transmit infection, which has been shown to negatively affect their perception of employment. In conclusion, it is important to form an image of a dental hygienist through the recognition of the correct internet information in the period of new infectious diseases.

An Acoustic Event Detection Method in Tunnels Using Non-negative Tensor Factorization and Hidden Markov Model (비음수 텐서 분해와 은닉 마코프 모델을 이용한 터널 환경에서의 음향 사고 검지 방법)

  • Kim, Nam Kyun;Jeon, Kwang Myung;Kim, Hong Kook
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.8 no.9
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    • pp.265-273
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    • 2018
  • In this paper, we propose an acoustic event detection method in tunnels using non-negative tensor factorization (NTF) and hidden Markov model (HMM) applied to multi-channel audio signals. Incidents in tunnel are inherent to the system and occur unavoidably with known probability. Incidents can easily happen minor accidents and extend right through to major disaster. Most incident detection systems deploy visual incident detection (VID) systems that often cause false alarms due to various constraints such as night obstacles and a limit of viewing angle. To this end, the proposed method first tries to separate and detect every acoustic event, which is assumed to be an in-tunnel incident, from noisy acoustic signals by using an NTF technique. Then, maximum likelihood estimation using Gaussian mixture model (GMM)-HMMs is carried out to verify whether or not each detected event is an actual incident. Performance evaluation shows that the proposed method operates in real time and achieves high detection accuracy under simulated tunnel conditions.

PULSE OXIMETER AS A DIAGNOSTIC TEST OF PULP VITALITY (Pulse Oximeter를 이용한 치수생활력측정)

  • Koo, Bon-Kyung;Lee, Jae-Ho;Lee, Jong-Gap
    • Journal of the korean academy of Pediatric Dentistry
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    • v.27 no.1
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    • pp.103-107
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    • 2000
  • Traditionally, EPT and thermal tests were used as diagnostic methods for pulp vitality test. The thermal and electrical stimulation tests are the methods to determine the vitality of a tooth based on its neuronal response. These have certain limitations, one of them is the difficulty of approaching the correct result in case of treatment of children. The reason is management problem caused by the unpleasant stimulation. Also, the response from patients are not objective, and false positive or false negative could be happened. Recently, laser doppler flowmetry and pulse oximeter which evaluate vascular integrity are introduced in an effort of overcoming to limitation of traditional methods. The principle of pulse oximeter is to and out level of oxygen saturation by ratio of the two pulses between emitted light and detected light penetrating them to the termination of body, such as ears or fingers. From this point of view, it can be applied to a tooth to determine its vitality. The objective of this study lies mainly on varifying pulse oximeter as a method of determining tooth vitality and providing basic data of its clinical implementation. The result of the research showed that level of oxygen saturation in vital teeth was average of 96.3% and 0.0% in pulpless teeth. As a comprehensive result, pulse oximeter could be an useful diagnostic equipment in determining of tooth vitality.

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Differential Diagnosis of Breast Mass and Staging of Breast Cancer Using F-18-FDG PET (F-18-FDG PET을 이용한 유방종괴의 감별진단과 유방암의 병기설정)

  • Yeo, Jeong-Seok;Lee, Dong-Soo;Kang, Keon-Wook;Noh, Dong-Young;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.33 no.6
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    • pp.502-511
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    • 1999
  • Purpose: F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been proven to be useful in the differential diagnosis of breast mass and staging of breast cancer. This study assessed the diagnostic accuracy of F-18-FDG PET in the differentiation of breast mass and staging of breast cancer. Materials and Methods: Total 42 patients who had breast mass underwent F-18-FDG PET (all female, 40: 10 year old). We compared F-18 FDG PET results with pathologic findings in 24 patients Results: In the differentiation of breast mass, sensitivity and specificity were 95% (19/20) and 77% (7/9) respectively. Three false positive cases were due to inflammation and one false negative patient had small tumor less than 1 cm. In the assessment of axillary lymph node status, sensitivity and specificity were 73% (8/11) and 100% (7/7) respectively. We found distant metastasis that were not suspected before F-18-FDG PET in 2 patients. Conclusion: F-18-FDG PET shows good diagnostic performance in differentiation of breast mass and staging of breast cancer.

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Traffic Flooding Attack Detection on SNMP MIB Using SVM (SVM을 이용한 SNMP MIB에서의 트래픽 폭주 공격 탐지)

  • Yu, Jae-Hak;Park, Jun-Sang;Lee, Han-Sung;Kim, Myung-Sup;Park, Dai-Hee
    • The KIPS Transactions:PartC
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    • v.15C no.5
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    • pp.351-358
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    • 2008
  • Recently, as network flooding attacks such as DoS/DDoS and Internet Worm have posed devastating threats to network services, rapid detection and proper response mechanisms are the major concern for secure and reliable network services. However, most of the current Intrusion Detection Systems(IDSs) focus on detail analysis of packet data, which results in late detection and a high system burden to cope with high-speed network environment. In this paper we propose a lightweight and fast detection mechanism for traffic flooding attacks. Firstly, we use SNMP MIB statistical data gathered from SNMP agents, instead of raw packet data from network links. Secondly, we use a machine learning approach based on a Support Vector Machine(SVM) for attack classification. Using MIB and SVM, we achieved fast detection with high accuracy, the minimization of the system burden, and extendibility for system deployment. The proposed mechanism is constructed in a hierarchical structure, which first distinguishes attack traffic from normal traffic and then determines the type of attacks in detail. Using MIB data sets collected from real experiments involving a DDoS attack, we validate the possibility of our approaches. It is shown that network attacks are detected with high efficiency, and classified with low false alarms.

The Prevention of Carryover in the Automated System With Fixed Tips (자동 분주기 Fixed Tip의 Carryover 방지를 위한 개선 방안)

  • Hwang, Bo-Ra;Au, Doo-Hee;Bae, Jin-Su;Park, Jong-O;Kim, Ji-Young;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.181-184
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    • 2009
  • Purpose: Automated system that immunoassay examination are used widely. However, sample to sample carryover can cause that the next patient sample is false positive. Materials and Methods: We test HBs Ag, HBs Ab, HBc Ab(IgG) with Automated pipetting system (Tecan). It was placed with very high concentrations followed by saline solution. During this experiment, The fixed tip of Automated system wash With 0.25 moL/L NaOH. The Measurement results of saline solution confirm the occurrence of carryover. Results: Results of saline solution with 0.25 moL/L NaOH cleaning process was measured 100% negative, And results of patient serum with 0.25 moL/L NaOH cleaning process is similar reported results. Conclusion: As Results, 0.25 moL/L NaOH cleaning process was avoid carryover in experiment, And we know results of the hepatitis test did not affected by this solution we recommend 0.25 moL/L NaOH cleaning process as the Prevention of carryover in the automated system with fixed Tips.

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Noninvasive Evaluation of Coronary Artery Bypass Graft Patency by Electron Beam Tomography (전자선 단층 촬영을 이용한 관상동맥 우회로 개존의 비침습적 평가)

  • 최규옥;김호석;조범구
    • Journal of Chest Surgery
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    • v.32 no.8
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    • pp.693-701
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    • 1999
  • Recently non-invasive diagnostic imaging replaced the invasive catheter angiography in the diagnosis of vascular disease. Catheter methods are now almost confined to the purpose of intervention. Coronary artery or coronary artery bypass graft still needs catheter technique because of small diameter and the cardiac motion. The last challenge for radiologists in this domain is to obtain a non-invasive imaging. Electron beam tomography(EBT) for high temporal resolution is able to obtain a coronary arteriogram or coronary artery bypass graft (CABG), of which CABG imaging is quite useful for the evaluation of patency. In our experience as well as others, the accuracy of EBT angiogram in evaluating CABG patency revealed that the accuracy of patency of saphenous vein grafts(SVG) is high due to relatively wide lumen, short and straight course and less influence from cardiac motion. The sensitivity and specificity of patency of SVGs were 92%, 97% respectively in the prospective evaluat on and 100% each in the retrospective evaluation. A false positive and a false negative case are rudimentary errors in the initial learing period. In contrast the analysis of left internal mammary artery(LIMA) graft was difficult due to the inherent small size and the adjacent surgical clips provoking beam-hardening artifact; therefore, the method of combining 3 dimensional reconstruction and flow mode study was important in improving the accuracy of LIMA patency. The sensitivity and specificity of LIMA patency were 100% and 80% in both prospective and retrospective evaluation. Therefore, EBT angiography is an accurate non-invasive diagnostic modality for evaluating the patency of CABG, particularly in SVGs. The accuracy can be improved with the improvement of the EBT and the development of the image reconstruction software.

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