• Title/Summary/Keyword: sensitive detection

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A Real Time PCR Assay for Detection and Quantitation of Canine Parvovirus Type 2 in the Feces of Dogs with Parvovirus Infection (실시간 중합효소연쇄반응법을 이용한 개 파보바이러스 감염증의 분변에서 바이러스 정량 분석)

  • koh Min-Soo;Sin So-Yeon;Kim Yong-Hwan;Koh Ba-Ra-Da;Lee Bong-Joo
    • Journal of Veterinary Clinics
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    • v.22 no.4
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    • pp.348-352
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    • 2005
  • We described a rapid, sensitive and reproducible real-time PCR assay for detection and quantitation of canine parvovirus type 2 in the feces of dogs with parvovirus infection. The method was demonstrated to be highly specific and sensitive, allowing a precise canine parvovirus type-2 quantitation over range of eight orders of magnitude from $10^2\;to\;10^9$ copies of standard DNA. Then, fecal samples from parvovirus infected dogs were analyzed by conventional PCR and real-time PCR. Real-time PCR is more sensitive than conventional PCR, allowing to detect low viral titers of CPV-2 in infected dogs. By real-time PCR, a wide range of parvovirus particles was found in the samples from $1.45\times10^6\;to\;9.45\times10^8$ copies/0.01g of feces. However, when dogs are in infection of parvovirus, it is difficult to prove that the numbers of peripheral blood leukocytes are correlated with those of fecal shedding virus.

Improved Detection of Viable Escherichia coli O157:H7 in Milk by Using Reverse Transcriptase-PCR

  • Choi, Suk-Ho;Lee, Seung-Bae
    • Food Science of Animal Resources
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    • v.31 no.2
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    • pp.158-165
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    • 2011
  • A sensitive reverse transcriptase-PCR (RT-PCR) method to detect viable Escherichia coli O157:H7 in milk was established. The primer sets were designed based on the nucleotide sequences of the rfbE (per) and wbdN genes in the O157 antigen gene cluster of E. coli O157:H7. RT-PCR using five different primer sets yielded DNA with sizes of 655, 518, 450, and 149-bp, respectively. All five of the E. coli O157:H7 strains were detected by RT-PCR, but 11 other bacterial species were not. The sensitivity of RT-PCR was improved by adding yeast tRNA as a carrier to the crude RNA extract. The RT-PCR amplifying the 149-bp DNA fragment was the most sensitive for detecting E. coli O157:H7 and the most refractory to the bactericidal treatments. Heat treatment at $65^{\circ}C$ for 30 min was the least inhibitory of all bactericidal treatments. Treatment with RNase A strongly inhibited the RT-PCR of heated milk but not unheated milk. This study described RT-PCR methods that are specific and sensitive with a detection limit of 10 E. coli O157:H7 cells, and showed that pre-treating milk samples with RNase A improved the specificity to detect viable bacteria by RT-PCR.

Structural damage detection in presence of temperature variability using 2D CNN integrated with EMD

  • Sharma, Smriti;Sen, Subhamoy
    • Structural Monitoring and Maintenance
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    • v.8 no.4
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    • pp.379-402
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    • 2021
  • Traditional approaches for structural health monitoring (SHM) seldom take ambient uncertainty (temperature, humidity, ambient vibration) into consideration, while their impacts on structural responses are substantial, leading to a possibility of raising false alarms. A few predictors model-based approaches deal with these uncertainties through complex numerical models running online, rendering the SHM approach to be compute-intensive, slow, and sometimes not practical. Also, with model-based approaches, the imperative need for a precise understanding of the structure often poses a problem for not so well understood complex systems. The present study employs a data-based approach coupled with Empirical mode decomposition (EMD) to correlate recorded response time histories under varying temperature conditions to corresponding damage scenarios. EMD decomposes the response signal into a finite set of intrinsic mode functions (IMFs). A two-dimensional Convolutional Neural Network (2DCNN) is further trained to associate these IMFs to the respective damage cases. The use of IMFs in place of raw signals helps to reduce the impact of sensor noise while preserving the essential spatio-temporal information less-sensitive to thermal effects and thereby stands as a better damage-sensitive feature than the raw signal itself. The proposed algorithm is numerically tested on a single span bridge under varying temperature conditions for different damage severities. The dynamic strain is recorded as the response since they are frame-invariant and cheaper to install. The proposed algorithm has been observed to be damage sensitive as well as sufficiently robust against measurement noise.

Association of GSTP1 and RRM1 Polymorphisms with the Response and Toxicity of Gemcitabine-cisplatin Combination Chemotherapy in Chinese Patients with Non-small Cell Lung Cancer

  • Yuan, Zhi-Jun;Zhou, Wen-Wu;Liu, Wei;Wu, Bai-Ping;Zhao, Jin;Wu, Wei;He, Yi;Yang, Shuo;Su, Jing;Luo, Yi
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4347-4351
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    • 2015
  • Background: Previous studies showed that genetic polymorphisms of glutathione S-transferase P1 (GSTP1) were involved in glutathione metabolism and genetic polymorphisms of ribonucleotide reductase (RRM1) were correlated with DNA synthesis. Here we explored the effects of these polymorphisms on the chemosensitivity and clinical outcome in Chinese non-small cell lung cancer (NSCLC) patients treated with gemcitabine-cisplatin regimens. Materials and Methods: DNA sequencing was used to evaluate genetic polymorphisms of GSTP1 Ile105Val and RRM1 C37A-T524C in 47 NSCLC patients treated with gemcitabine-cisplatin regimens. Clinical response was evaluated according to RECIST criteria after 2 cycles of chemotherapy and toxicity was assessed by 1979 WHO criteria (acute and subacute toxicity graduation criteria in chemotherapeutic agents). Results: There was no statistical significance between sensitive and non-sensitive groups regarding the genotype frequency distribution of GSTP1 Ile105Val polymorphism (p>0.05). But for RRM1 C37A-T524C genotype, sensitive group had higher proportion of high effective genotype than non-sensitive group (p=0.009). And according to the joint detection of GSTP1 Ile105Val and RRM1 C37A-T524C polymorphisms, the proportion of type A (A/A + high effective genotype) was significantly higher in sensitive group than in non-sensitive group (p=0.009). Toxicity showed no correlation with the genotypes between two groups (p>0.05). Conclusions: Compared with single detection of genetic polymorphisms of GSTP1 Ile105Val or RRM1 C37A-T524C, joint detection of both may be more helpful for patients with NSCLC to receive gemcitabine-cisplatin regimens as the first-line chemotherapy. Especially, genetic polymorphism of RRM1 is more likely to be used as an important biomarker to predict the response and toxicity of gemcitabine-cisplatin combination chemotherapy in NSCLC.

Learning-based Improvement of CFAR Algorithm for Increasing Node-level Event Detection Performance in Acoustic Sensor Networks (음향 센서 네트워크에서의 노드 레벨 이벤트 탐지 성능향상을 위한 학습 기반 CFAR 알고리즘 개선)

  • Kim, Youngsoo
    • IEMEK Journal of Embedded Systems and Applications
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    • v.15 no.5
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    • pp.243-249
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    • 2020
  • Event detection in wireless sensor networks is a key requirement in many applications. Acoustic sensors are one of the most frequently used sensors for event detection in sensor networks, but they are sensitive and difficult to handle because they vary greatly depending on the environment and target characteristics of the sensor field. In this paper, we propose a learning-based improvement of CFAR algorithm for increasing node-level event detection performance in acoustic sensor networks, and verify the effectiveness of the designed algorithm by comparing and evaluating the event detection performance with other algorithms. Our experimental results demonstrate the superiority of the proposed algorithm by increasing the detection accuracy by more than 45.16% by significantly reducing false positives by 7.97 times while slightly increasing the false negative compared to the existing algorithm.

Biosensors for On-the-spot Detection of Bacteria from Foods (식품 유래 박테리아 현장검출용 바이오센서)

  • Lee, Won-Il;Kim, Bo-Yeong;Son, Young-Min;Kim, Ari;Lee, Nae-Eung
    • Journal of Sensor Science and Technology
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    • v.25 no.5
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    • pp.354-364
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    • 2016
  • Recently there have been extensive research activities on the development of on-the-spot detection technologies for bacteria from foods due to growing high demand for food safety. In particular, on-the-spot detection devices using biosensors with rapid, highly sensitive and multiplexed sensing capability are promising for portable or mobile applications. Firstly, issues related to on-the-spot bacteria detection are discussed. Then, detection methods for bacteria, types of biosensors depending on transducing principle and receptors, and platforms for integration of biosensors and signal readers are reviewed. Finally, prospects for development of on-the-spot detection devices are summarized.

Intelligent Electronic Nose System for Detection of VOCs in Exhaled Breath

  • Byun, Hyung-Gi;Yu, Joon-Bu
    • Journal of Sensor Science and Technology
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    • v.28 no.1
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    • pp.7-12
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    • 2019
  • Significant progress has been made recently in detection of highly sensitive volatile organic compounds (VOCs) using chemical sensors. Combined with the progress in design of micro sensors array and electronic nose systems, these advances enable new applications for detection of extremely low concentrations of breath-related VOCs. State of the art detection technology in turn enables commercial sensor systems for health care applications, with high detection sensitivity and small size, weight and power consumption characteristics. We have been developing an intelligent electronic nose system for detection of VOCs for healthcare breath analysis applications. This paper reviews our contribution to monitoring of respiratory diseases and to diabetic monitoring using an intelligent electronic nose system for detection of low concentration VOCs using breath analysis techniques.

Nanowell Array based Sensor and Its Packaging

  • Lee, JuKyung;Akira, Tsuda;Jeong, Myung Yung;Lee, Hea Yeon
    • Journal of the Microelectronics and Packaging Society
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    • v.21 no.3
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    • pp.19-24
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    • 2014
  • This article reviews the recent progress in nanowell array biosensors that use the label-free detection protocol, and are detected in their natural forms. These nanowell array biosensors are fabricated by nanofabrication technologies that should be useful for developing highly sensitive and selective also reproducible biosensors. Moreover, electrochemical method was selected as analysis method that has high sensitivity compared with other analysis. Finally, highly sensitive nanobiosensor was achieved by combining nanofabrication technologies and classical electrochemical method. Many examples are mentioned about the sensing performance of nanowell array biosensors will be evaluated in terms of sensitivity and detection limit compared with other micro-sized electrode without nanowell array.

Electrochemical Behavior of Norfloxacin and Its Determination at Poly(methyl red) Film Coated Glassy Carbon Electrode

  • Huang, Ke-Jing;Xu, Chun-Xuan;Xie, Wan-Zhen
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.988-992
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    • 2008
  • A poly(methyl red) film-modified glassy carbon electrode (PMRE) was fabricated for determination of norfloxacin (NFX). The electrochemical behavior of NFX was investigated and a well-defined oxidation peak with high sensitivity was observed at the film electrode. PMRE greatly enhanced the oxidation peak current of NFX owing to the extraordinary properties of poly(methyl red) film. Based on this, a sensitive and simple voltammetric method was developed for measurement of NFX. A sensitive linear voltammetric response for NFX was obtained in the concentration range of $1\;{\times}\;10^{-6}\;-\;1\;{\times}\;10^{-4}$ mol/L and the detection limit was $1\;{\times}\;10^{-7}$ mol/L using linear sweep voltammetry (LSV). The proposed method possessed advantages such as low detection limit, fast response, low cost and simplicity. The practical application of this new analytical method was demonstrated with NFX pharmaceuticals.

Specific detection of salmonella enteritidis using polymerase chain reaction method (PCR을 이용한 salmonella enteritidis의 특이적 검출)

  • 조미영;여용구;김영섭;이정학;이병동
    • Korean Journal of Veterinary Service
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    • v.23 no.3
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    • pp.227-233
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    • 2000
  • Salmonella enteritidis is the most prevalent etiologic agents of foodborne acute gastroenteritis. Direct isolation and identification of S enteritidis are time consuming work and not so highly sensitive. This study was conducted to develop for the specific detection of S enteritidis using polymerase chain reaction(PCR). PCR primers were selected to amplify a 351-base pair(bp) DNA fragment from the salmonella plasmid virulence A(spv A) gene of S enteritidis. With the primers, 351 bp DNA products were amplified from S enteritidis but not from other B, D, Cl serogroup Salmonella spp. It was sensitive to detect up to 40 pg of template DNA by agarose gel electrophoresis. This PCR assay is very rapid and specific method and less time consuming than the standard bacteriological methods.

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