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Objective To study the influence of the radius of the active zone of the plane source and the horizontal distance between the source center and the center of the detection window on the detection efficiency of low-background α/β measuring instruments. Methods The geometric factor was calculated under different conditions in MATLAB, and a traceable plane source was used to test and analyze two commonly used measuring instruments. Results With the other parameters unchanged, when the radius of the active zone R1 = 9 mm, the G value was greatest; and when the horizontal distance a = 0 mm, the G value was greatest. According to the calculation formula of the verification regulation, for the 90Sr-90Y planar source, at the maximum value of a, the detection efficiency of FYFS-400X was 1.2% lower, and that of MPC-9604 was 3.2% lower; for the 241Am planar source, the detection efficiency of MPC-9604 was 1.9% lower at the maximum value of a. Conclusion The geometric factor decreases with the increase in the radius of the active zone and the horizontal distance between the source center and the center of the detection window. At the central position, the geometric factor has less influence on the relative standard uncertainty of detection efficiency. When using a standard plane source for counting, measures should be taken to ensure that the plane source is always centrally located in the sample tray.
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Objective:To investigate the radiation dose and detection efficiency of artificial intelligence (AI) system for solid nodules in chest phantom with different scanning protocols.Methods:A total of 60 simulated nodules with different CT values and diameters were uniformly placed in each lung lobe and lung segment of the anthropomorphic chest phantom. GE Revolution evo CT was used to scan the chest phantom. 64 groups of images with different scanning parameters were collected at the tube voltage of 80, 100, 120, 140 kV, different noise indexes (NI 10-40 with interval 2), and other fixed parameters. The detection result of simulated nodules were recorded on AI software, and the detection rate and false detection rate were calculated, respectively, for different shapes of nodules. The mean volume CT dose index (CTDI vol) and dose length product (DLP) of each scan were recorded. Results:There were no statistically significant differences in the detection rate and false detection rate of spherical nodules and irregular nodules at different tube voltages( P > 0.05), but there were and statistically significant with different noise indices ( F=10.57, 17.77, 9.33, P < 0.001). Different tube voltages had no statistical significance for CTDI vol and DLP ( P > 0.05), while different noise indices had statistical significance for CTDI vol and DLP ( F=59.87, 60.92, P < 0.001). The detection rates of nodules were moderately or weakly correlated with noise indices, CTDI vol and DLP ( r=0.43, 0.56, -0.58, -0.78, P<0.05), but no correlation with tube voltage ( P>0.05). Conclusions:Scanning protocol has an impact on AI detection efficiency of pulmonary nodules. Reasonable scanning parameters should be selected according to different image quality requirements in clinical practice.
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Objective To establish a fluorescent assay for rapid detection of Plasmodium falciparum based on recombinaseaided amplification (RAA) and CRISPR-Cas12a system,and to preliminarily evaluate the diagnostic efficiency of this system.. Methods The 18S ribosomal RNA (rRNA) gene of P. falciparum was selected as the target sequence, and three pairs of RAA primers and CRISPR-derived RNA (crRNA) were designed and synthesized. The optimal combination of RAA primers and crRNA was screened and the reaction conditions of the system were optimized to create a fluorescent RAA/CRISPR-Cas12a system. The plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 was generated, and diluted into concentrations of 1 000, 100, 10, 1 copy/μL for the fluorescent RAA/CRISPR-Cas12a assay, and its sensitivity was evaluated. The genomic DNA from P. vivax, P. malariae, P. ovum, hepatitis B virus, human immunodeficiency virus and Treponema pallidum was employed as templates for the fluorescent RAA/CRISPR-Cas12a assay, and its specificity was evaluated. Fifty malaria clinical samples were subjected to the fluorescent RAA/CRISPR-Cas12a assay and nested PCR assay, and the consistency between two assays was compared. In addition, P. falciparum strain 3D7 was cultured in vitro. Then, the culture was diluted into blood samples with parasite densities of 1 000, 500, 200, 50, 10 parasites/μL with healthy volunteers’ O-positive red blood cells for the RAA/CRISPR-Cas12a assay, and the detection efficiency was tested. Results The Pf-F3/Pf-R3/crRNA2 combination, 2.5 μL as the addition amount of B buffer, 40 min as the RAA reaction time, 37 °C as the reaction temperature of the CRISPR-Cas12a system were employed to establish the fluorescent RAA/CRISPR-Cas12a system. Such a system was effective to detect the plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 at a concentration of 1 copy/μL, and presented fluorescent signals for detection of P. falciparum, but failed to detect P. ovum, P. malariae, P. vivax, T. pallidum, hepatitis B virus or human immunodeficiency virus. The fluorescent RAA/CRISPR-Cas12a system and nested PCR assay showed completely consistent results for detection of 50 malaria clinical samples (kappa = 1.0, P < 0.001). Following 6-day in vitro culture of the P. falciparum strain 3D7, 10 mL cultures were generated and the fluorescent RAA/CRISPR-Cas12a system showed the minimal detection limit of 50 parasites/μL. Conclusion The fluorescent RAA/CRISPR-Cas12a system is rapid, sensitive and specific for detection of P. falciparum, which shows promising value for rapid detection and risk monitoring of P. falciparum.
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@#<b>Objective</b> To correct the counting loss of <sup>37</sup>Ar below the activity threshold during the measurement of the absolute activity of the inert radioactive gas <sup>37</sup>Ar using the proportional counter filled with gas. <b>Methods</b> Monte Carlo simulation with Geant4 was performed to establish a proportional counter model and output the energy deposition spectrum of <sup>37</sup>Ar, which were used to simulate and analyze the causes and correction of counting loss. <b>Results</b> The photon detection efficiency was only 38.7% at 60 kPa. The counting loss was mainly caused by the wall effect produced by the photons, which could be reduced by increasing the gas pressure and corrected by extrapolation. The influence of wall effect at 100 kPa was 4.4%, and the deviation between simulation and experiment was < 0.6%. <b>Conclusion</b> A factor could be calculated by Geant4 simulation for the correction of counting loss, thus achieving the accurate measurement of <sup>37</sup>Ar activity by proportional counter.
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OBJECTIVES@#To study the detection efficiency of trio full sibling with another known full sibling reference added under different number of autosomal STR typing systems.@*METHODS@#Based on 43 detection systems consisting of 13 to 55 representative autosomal STR loci, 10 000 true families (full sibling group) and 10 000 false families (unrelated individual group) were randomly simulated. The full sibling index (FSI) was calculated based on the method of family reconstruction. The cumulative sibling relationship index (CFSI) of 0.000 1 and 10 000 were used as the evaluation thresholds, and the detection efficiency parameters were calculated and compared with the identification of the duo full sibling testing.@*RESULTS@#With the increasing number of STR loci, the error rate and inability of judgement rate gradually decreased; the sensitivity, specificity, correct rate of judgment and other parameters gradually increased, and the system efficiency gradually improved. Under the same detection system, trio full sibling testing showed higher sensitivity, specificity, system efficiency and lower inability of judgement rate compared with duo full sibling testing. When the system efficiency was higher than 0.85 and inability of judgement rate was less than 0.01%, at least 20 STRs should be detected for trio full sibling testing, which was less than 29 STRs required by duo full sibling testing.@*CONCLUSIONS@#The detection efficiency of trio full sibling testing is superior to that of duo full sibling testing with the same detection system, which is an effective identification scheme for laboratories with inadequate detection systems or for materials with limited conditions.
الموضوعات
Humans , Siblings , Microsatellite Repeats/genetics , DNA Fingerprinting , Gene Frequencyالملخص
OBJECTIVE@#To evaluate the performance of recombinase-aided amplification (RAA) assay in detection of Clonorchis sinensis metacercariae in freshwater fish samples, so as to provide insights into standardization and field application of this assay.@*METHODS@#Wild freshwater fish samples were collected in the rivers of administrative villages where C. sinensis-infected residents lived in Jiangyan District, Xinghua County and Taixing County of Taizhou City, Jiangsu Province from June to September 2022. Genomic DNA was extracted from six freshwater fish specimens (5 g each) containing 0, 1, 2, 4, 8 and 16 C. sinensis metacercariae for fluorescent RAA assay, and the diagnostic sensitivity was evaluated. Fluorescent RAA assay was performed with genomic DNA from C. sinensis, Metorchis orientalis, Haplorchis pumilio and Centrocestus formosanus metacercariae as templates to evaluate its cross-reactions. In addition, the detection of fluorescent RAA assay and direct compression method for C. sinensis metacercariae was compared in field-collected freshwater fish samples.@*RESULTS@#Positive amplification was found in fresh-water fish specimens containing different numbers of C. sinensis metacercariae, and fluorescent RAA assay was effective to detect one C. sinensis metacercaria in 5 g freshwater fish specimens within 20 min. Fluorescent RAA assay tested negative for DNA from M. orientalis, H. pumilio and C. formosanus metacercariae. Fluorescent RAA assay and direct compression method showed 5.36% (93/1 735) and 2.88% (50/1 735) detection rates for C. sinensis metacercariae in 1 735 field-collected freshwater fish samples, with a statistically significant difference seen (χ2 = 478.150, P < 0.001). There was a significant difference in the detection of C. sinensis metacercariae in different species of freshwater fish by both the direct compression method (χ2 = 11.20, P < 0.05) and fluorescent RAA assay (χ2 = 20.26, P < 0.001), and the detection of C. sinensis metacercariae was higher in Pseudorasbora parva than in other fish species by both the direct compression method and fluorescent RAA assay (both P values < 0.05).@*CONCLUSIONS@#Fluorescent RAA assay has a high sensitivity for detection of C. sinensis metacercariae in freshwater fish samples, and has no cross-reactions with M. orientalis, H. pumilio or C. formosanus metacercariae. Fluorescent RAA assay shows a higher accuracy for detection of C. sinensis infections in field-collected freshwater fish than the direct compression method.
الموضوعات
Animals , Clonorchis sinensis/genetics , Metacercariae/genetics , Recombinases , Fresh Water , Fishes , DNA , Fish Diseases/diagnosisالملخص
Objective To compare the efficiency of multiple etiological techniques for detection of Schistosoma japonicum infections in wild mice, so as to provide technical supports to assessment of schistosomiasis transmission risk. Methods Wild mice were captured with baited traps at night in Oncomelania hupensis snail-infested settings in schistosomiasis-endemic foci of Anhui Province from October to November, 2022. S. japonicum infections were detected in wild mice using microscopy of mouse liver tissues, microscopy of mouse mesenteric tissues, microscopy of mouse liver tissue homogenates, miracidial hatching test of mouse liver tissue homogenates, Kato-Katz technique and miracidial hatching test of mouse stool samples alone and in combinations. Identification of S. japonicum eggs or miracidia by any of these six assays was defined as an infection. The sensitivity of six assays alone or in combinations was compared for detection of S. japonicum infections in wild mice. Results A total of 1 703 wild mice were captured, with 366 wild mice detected positive for S. japonicum (21.49%). There were significant differences in the prevalence of S. japonicum infections in wild mice by six assays (Q = 529.33, P < 0.001) and in the sensitivity of six assays for detection of S. japonicum infections in wild mice (χ2 = 527.78, P < 0.001). In addition, the combination of microscopy of mouse liver tissues and mesenteric tissues, combination of microscopy of mouse liver tissues and liver tissue homogenates and combination of microscopy of mouse liver tissues, microscopy of mesenteric tissues, microscopy of liver tissue homogenates and Kato-Katz technique showed 86.61%, 87.16% and 97.27% sensitivities for detection of S. japonicum infections in wild mice, respectively. Conclusions Diverse etiological assays show various efficiencies for detection of S. japonicum infections in wild mice. Combination of microscopy of mouse liver tissues and microscopy of mesenteric tissues, and combination of microscopy of mouse liver tissues and microscopy of liver tissue homogenates are potential approaches for field detection of S. japonicum infections in wild mice.
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Objective:To simulate the effects of different thyroid-neck phantoms and monitoring positions on the detection efficiency of portable γ spectrometer, and to provide guidance for more accurate on-site measurement of 131I activity in the human thyroid. Methods:Based on the models of 4 typical thyroid-neck phantoms and a 3-inch NaI (TI) γ spectrometer used for the measurement of 131I in the thyroid and combined with the possible field monitoring scenarios, the Monte Carlo method was used to simulate and calculate the detection efficiency of the spectrometer under different conditions of monitoring distance, thyroid depth and thyroid volume. Results:The detection efficiency decreased significantly with the increase in the distance between the detector and the neck surface. The efficiency close to the neck surface was about 15 times that at 15 cm away from the neck surface. The detection efficiency decreased significantly with the increase in thyroid depth. When it was measured at the surface of the neck, the detection efficiency of thyroid at depth of 2 mm was about 3.6 times that of 30 mm. The detection efficiency decreases with the increase in thyroid volume. When it was measured at the neck surface, the detection efficiency of thyroid with 1 ml volume was 1.71 times that with 30 ml. The detection efficiency decreased with the center-point offset of the detector, especially at the neck surface, an offset of 2 cm would reduce the detection efficiency by about 15%.Conclusions:Not only the measurement distance used in calibration, but also the information of the depth and volume of thyroid in the neck-thyroid phantom, is important to know in advance for an accurate measurement of 131I activity in thyroid by using a portable gamma spectrometer.
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Objective To evaluate the efficiency of a recombinase-aided amplification (RAA) assay for the detection of Schistosoma japonicum infections in Oncomelania hupensis snails. Methods A group test was employed. Fifty Oncomelania snails were collected as a detection sample. The detection samples without infected snails were designated as negative specimens, while the detection samples that contained different numbers of infected snails were designated as positive specimens. A total of 10 negative specimens, 10 positive specimens containing 1 infected snail, 20 positive specimens containing 2 infected snails and 10 positive specimens containing 3 infected snails were assigned. Following random grouping, 40 specimens were subject to the florescent RAA assay using a blind method. The miradium shedding method served as a gold standard, and the sensitivity, specificity, Youden’s index and coincidence rate of the florescent RAA assay were estimated. In addition, 20 samples consisted of 5 negative specimens and 15 positive specimens with 1, 2 and 3 infected snails respectively were grouped randomly. The same specimens were detected using the crushing method and fluorescent RAA assay with the blind method in a paired-design manner. Then, the test results were compared and analyzed. Results Florescent RAA assay detected 29 positives in the 30 specimens containing different numbers of infected snails, with a sensitivity of 96.67%, and 8 negatives in the 10 detection specimens without infected snails, with a specificity of 80.00%, showing a Youden’s index of 0.77. The coincidence rate was 100% among 10 repeated assays for a detection specimen. In addition, there was no significant difference in the detection of infected snails between the florescent RAA assay and the crushing method (χ2 = 0, P > 0.05), and the actual coincidence rates of the florescent RAA assay and crushing method were 95.00% (19/20) and 90.00% (18/20) with the real results, respectively. Conclusion Fluorescent RAA assay has a favorable efficiency for the detection of S. japonicum infections in Oncomelania snails, which shows a potential in screening of S. japonicum-infected Oncomelania snails.
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Objective To develop a fluorescent recombinase-aided isothermal amplification (RAA)-based nucleic acid assay for detection of Leshimania. Methods Specific primers and probes were designed targeting Leishmania internal transcribed spacer 1 (ITS1) gene for RAA assay, and a fluorescent RAA assay was developed for detection of Leishmania following screening of primer pairs and optimization of primer and probe concentrations. The sensitivity of RAA assay for detection of Leishmania was evaluated using recombinant plasmid containing Leishmania ITS1 gene sequences at different copies and Leshimania genomic DNA at different concentrations as templates, and the specificity of RAA assay for detection of Leishmania was evaluated using the genomic DNA of transfusion-transmitted parasites, including Babesia microti, Toxoplasma gondii, Plamodium vivax, P. ovale, P. falciparum, P. malariae, L. donovani and L. infantum. Results After the optimal primer pair was screened from 9 pairs of primer combinations, the final primer and probe concentrations were optimized as 0.3 μmol/L and 0.08 μmol/L, respectively. Nucleic acid detection of Leishmania was completed by the fluorescent RAA assay at an isothermal temperature of 39 °C within 20 min. Remarkable florescent signals were seen within 5 min following RAA detection of genomic DNA of L. donovani and L. infantum, and no cross-reactions were observed with B. microti, T. gondii, P. vivax, P. ovale, P. falciparum or P. malariae. The lowest limitation of detection of the fluorescent RAA assay was 10 copies/μL recombinant plasmid containing Leishmania ITS1 gene sequences and 1 fg/μL Leishmania genomic DNA. Conclusions A rapid, simple, sensitive and specific fluorescent RAA assay is successfully developed for detection of L. donovani and L. infantum, which is effective for field screening of leishmaniasis.
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Objective To establish a nucleic acid assay for detection of Paragonimus skrjabini based on the recombinase-aided isothermal amplification (RAA) technique, and to preliminarily evaluate its detection efficiency. Methods The metacercariae of P. skrjabini, P. westermani and Euparagonimus cenocopiosus were isolated from crabs, and genomic DNA was extracted for molecular characterization. The cytochrome coxidase 1 (cox1) gene sequence of P. skrjabini was selected as the target gene fragment, and the primers and probes were designed, screened and synthesized for RAA assay. The genomic DNA of P. skrjabini metacercariae from Jiyuan City and Yiyang County of Luoyang City, Henan Province were used as templates for verification of the fluorescent RAA assay. The fluorescent RAA assay was performed to detect different concentrations of plasmids containing target gene fragment and P. skrjabini metacercariae genomic DNA to determine the sensitivity. Fluorescent RAA assay was performed with recombinant plasmids containing P. skrjabini cox1 gene sequences at different concentrations and P. skrjabini genomic DNA as templates to evaluate its sensitivity, and the genomic DNA of P. westermani, E. cenocopiosus, Clonorchis sinensis and Schistosoma japonicum was detected with fluorescent RAA assay to evaluate its specificity. Results P. skrjabini, P. westermani and E. cenocopiosus metacercariae were isolated from crabs, respectively. Molecular characterization and phylogenetic analysis confirmed their homology with the genes sequences of standard Paragonimus strains in GenBank. A fluorescent RAA assay was successfully established for nucleic acid detection of P. skrjabini, and the genomic DNA of P. skrjabini metacercariae from Jiyuan City and Yiyang County of Luoyang City, Henan Province was amplified using the fluorescent RAA assay within 5 min, while the negative control was not amplified. If the recombinant plasmid containing P. skrjabini cox1 gene sequences was used as templates, the fluorescent RAA assay showed the lowest detection limit of 10 copies/μL, and positive amplification was observed within 5 min. If genomic DNA was used as templates, the fluorescent RAA assay showed the lowest detection limit of 10 pg/μL, and all positive amplifications were found within 5 to 10 min. In addition, the fluorescent RAA assay was tested negative for P. westermani, E. cenocopiosus, C. sinensis and S. japonicum. Conclusions A rapid, sensitive and specific fluorescent RAA assay is successfully established for nucleic acid detection of P. skrjabini, which has potential values in rapid field detection and species identification in freshwater crabs in areas endemic for P. skrjabini.
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To improve the diagnostic efficiency of prostate cancer (PCa) and reduce unnecessary biopsies, we defined and analyzed the diagnostic efficiency of peripheral zone prostate-specific antigen (PSA) density (PZ-PSAD). Patients who underwent systematic 12-core prostate biopsies in Shanghai General Hospital (Shanghai, China) between January 2012 and January 2018 were retrospectively identified (n = 529). Another group of patients with benign prostatic hyperplasia (n = 100) were randomly preselected to obtain the PSA density of the non-PCa cohort (N-PSAD). Prostate volumes and transition zone volumes were measured using multiparameter magnetic resonance imaging (mpMRI) and were combined with PSA and N-PSAD to obtain the PZ-PSAD from a specific algorithm. Receiver operating characteristic (ROC) curve analysis was used to assess the PCa detection efficiency in patients stratified by PSA level, and the area under the ROC curve (AUC) of PZ-PSAD was higher than that of PSA, PSA density (PSAD), and transition zone PSA density (TZ-PSAD). PZ-PSAD could amend the diagnosis for more than half of the patients with inaccurate transrectal ultrasonography (TRUS) and mpMRI results. When TRUS and mpMRI findings were ambiguous to predict PCa (PIRADS score ≤3), PZ-PSAD could increase the positive rate of biopsy from 21.7% to 54.7%, and help 63.8% (150/235) of patients avoid unnecessary prostate biopsy. In patients whose PSA was 4.0-10.0 ng ml
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Abstract During the last year the Group of Atmospheric Electricity Phenomena (FEA/UFPR) developed a short range lightning location network based on a sensor device called Storm Detector Network (SDN), along with a set of algorithms that enables to track storms, determining the Wide Area Probability (WAP) of lightning occurrence, risk level of lightning and Density Extension of the Flashes (DEF), using the geo-located lightning information as input data. These algorithms compose a Dashboard called Tracking Storm Interface (TSI), which is the visualization tool for an experimental short range Storm Detector network prototype in use on the region of Curitiba-Paraná, Brazil. The algorithms make use of Geopandas and clustering algorithms to locate storms, estimate centroids, determine dynamic storm displacement and compute parameters of thunderstorms like velocity, head edge of electrified cloud, Mean Stroke Rate, and tracking information, which are important parameters to improve the alert system which is subject of this research. To validate these algorithms we made use of a simple storm simulation, which enabled to test the system with huge amounts of data. We found that, for long duration storms, the tracking results, velocity and directions of the storms are coherent with the values of simulation and can be used to improve an alert system for the Storm Detector network. WAP can reach at least 75% of prediction efficiency when used 6 past WAP data, but can reach 98.86% efficiency when more data is available. We use storm dynamics to make improved alert predictions, reaching an efficiency of ~87%.
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Disaster Warning/methods , Reminder Systems/supply & distribution , Storms , Accidents Caused by Electrical Discharges/prevention & controlالملخص
Objective To establish a recombinase-aided isothermal amplification (RAA) assay for the nucleic acid detection of Angiostrongylus cantonensis. Methods The internal transcribed spacer-1 (ITS1) gene sequence of A. cantonensis was used as the detection target sequence, and the specific primers and probes were designed and synthesized, followed by screening of the primers and probes with the highest specificity, to establish the basic and fluorescent RAA assay for nucleic acid detection of A. cantonensis. The sensitivity of the fluorescent RAA assay was evaluated by using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the template DNA samples, and the specificity of the fluorescent RAA assay was evaluated by using the genomic DNA from A. cantonensis, Schistosoma mansoni, Ascaris lumbricoides, Clonorchis sinensis, Echinococcus granulosus and Ancylostoma duodenale, as well as Pomacea canaliculata and Biomphalaria straminea snail tissues as the template DNA samples. Results A fluorescent RAA assay was successfully established for nucleic acid detection of A. cantonensis, which achieved real-time amplification of the specific DNA fragment of A. cantonensis within 20 min at 37 ℃. By using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the DNA templates, the lowest detection limits of the fluorescent RAA assay were 10 copies/μL of recombinant plasmids and 100 pg/μL of genomic DNA, respectively. The fluorescent RAA assay was negative for detection of the genomic DNA from A. cantonensis, S. mansoni, A. lumbricoides, C. sinensis, E. granulosus, A. duodenale, and P. canaliculata and B. straminea snail tissues. Conclusions A simple, rapid fluorescent RAA assay has been successfully established, which has a high sensitivity and specificity for the nucleic acid detection of A. cantonensis.
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Objective To establish a recombinase aided isothermal amplification (RAA) assay for detection of Clonorchis sinensis. Methods The 18S ribosomal RNA (18S rRNA) sequence of C. sinensis was used as the target sequence, and specific primers and probes were designed, synthesized and screened to establish a rapid fluorescent RAA assay for the detection of C. sinensis. Then, the sensitivity of the fluorescent RAA assay was evaluated using the recombinant plasmids containing various copy numbers of DNA fragments and C. sinensis genomic DNA at various concentrations, and the specificity of the fluorescent RAA as say was evaluated using the genomic DNA of Ascaris lumbricoides, Echinococcus granulosus, Schistosoma japonicum, Ancylostoma duodenale and S. mansoni as templates. DNA samples were extracted from the feces containing C. sinensis eggs and freshwater fish containing metacercaria for the fluorescent RAA assay, and the performance for detection of C. sinensis-infected samples was preliminarily assessed in the field. Results A fluorescent RAA assay for detection of C. sinensis was successfully established, which was feasible for specific amplification of C. sinensis genomic DNA at 39 °C within 20 min. The lowest detection limit was 10 copies/μL if the recombinant plasmid containing various copy numbers of DNA fragments was used as a template, and the lowest detection limit was 3 pg/μL if the C. sinensis genomic DNA at various concentrations served as a template. All detections were negative if the genomic DNA of A. lumbricoides, E. granulosus, S. japonicum, A. duodenale, and S. mansoni was used as templates. In addition, the fluorescent RAA assay showed a high performance for the detection of C. sinensis-infected samples in the field, which successfully detected C. sinensis-infected human and rat fecal samples and Pseudorasbora parva samples. Conclusion A fluorescent RAA assay is successfully established, which is simple, rapid, sensitivity and specific for detection of C. sinensis.
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Objective To establish a recombinase aided isothermal amplification (RAA) assay for detection of Clonorchis sinensis. Methods The 18S ribosomal RNA (18S rRNA) sequence of C. sinensis was used as the target sequence, and specific primers and probes were designed, synthesized and screened to establish a rapid fluorescent RAA assay for the detection of C. sinensis. Then, the sensitivity of the fluorescent RAA assay was evaluated using the recombinant plasmids containing various copy numbers of DNA fragments and C. sinensis genomic DNA at various concentrations, and the specificity of the fluorescent RAA as say was evaluated using the genomic DNA of Ascaris lumbricoides, Echinococcus granulosus, Schistosoma japonicum, Ancylostoma duodenale and S. mansoni as templates. DNA samples were extracted from the feces containing C. sinensis eggs and freshwater fish containing metacercaria for the fluorescent RAA assay, and the performance for detection of C. sinensis-infected samples was preliminarily assessed in the field. Results A fluorescent RAA assay for detection of C. sinensis was successfully established, which was feasible for specific amplification of C. sinensis genomic DNA at 39 °C within 20 min. The lowest detection limit was 10 copies/μL if the recombinant plasmid containing various copy numbers of DNA fragments was used as a template, and the lowest detection limit was 3 pg/μL if the C. sinensis genomic DNA at various concentrations served as a template. All detections were negative if the genomic DNA of A. lumbricoides, E. granulosus, S. japonicum, A. duodenale, and S. mansoni was used as templates. In addition, the fluorescent RAA assay showed a high performance for the detection of C. sinensis-infected samples in the field, which successfully detected C. sinensis-infected human and rat fecal samples and Pseudorasbora parva samples. Conclusion A fluorescent RAA assay is successfully established, which is simple, rapid, sensitivity and specific for detection of C. sinensis.
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Objective To explore the effeetiviness of the method of LabSOCS(Laboratory sourceless calibration software)efficiency calibration in laboratory rapid analysis for emergency monitoring of nuclear incidents.Methods The detection efficiency of three kinds of environmental samples in emergency monitoring Wag calculated bY using the LabSOCS efficiency calibration method,and compared with the values that were obtained by way of radioactive source calibration method.Results The maximum relative deviation of the detection efficiency between the two methods was less than 15%,and the values with relative deviation less than 5%accounted for 70%.Conclusions The LabSOCS efficiency calibration method might take the place of radioactive source efficiency calibration method,and meet the requirement of rapid analysis in emergency monitoring of the nuclear incidents.