| 2 | Concordance of the point-of-care circulating cathodic antigen test for the diagnosis of intestinal schistosomiasis in a low endemicity area显示文摘Background:The Kato-Katz technique is recommended worldwide for the diagnosis of intestinal schistosomiasis,detecting parasite eggs in feces of infected people.However,new tests have been developed in order to facilitate diagnosis,e.g.by detection of specific antigens secreted by schistosomes,such as the circulating cathodic antigen(CCA).The aim of this study was to evaluate the performance of the point-of-care circulating cathodic antigen test(POC-CCA)compared to the Kato-Katz technique in a low prevalence area in the Amazon Region,located in the municipality of Primavera,State of Para,Brazil.Methods:Positivity rates of the POC-CCA test and the Kato-Katz technique were calculated.The sensitivity,specificity,accuracy and kappa coefficient were determined by comparing both methods.The reference standard was established using 16 Kato-Katz slides,12 of the first fecal sample,two of the second and two of the third one.The study also included the concordance between POC-CCA results and different numbers and combinations of Kato-Katz slides.Results:The prevalence of schistosomiasis according to the reference standard or POC-CCA test reached a rate of 9.4%or 23.9%,respectively,among a total of 372 participants.The positivity rates by the Kato-Katz technique increased from 2.4 to 9.4%,according to the increase in the number of slides examined and fecal samples colleaed.A sensitivity of 55.6%,specificity 76.9%,accuracy 76%and k coefficient of 0.06 was observed by comparing one slide of the first sample and POC-CCA.Comparing 6 slides from three different samples,two slides of each,with POC-CCA resulted in a sensitivity of 583%,specificity 78.4%,accuracy 77%and k coefficient of 0.16.Finally,the comparison of 16 slides from three different samples with POC-CCA revealed a sensitivity of 65.7%,specificity 80.4%,accuracy 79%,and k coefficient of 0.27.Conclusions:The immunochromatographic test has the potential to be an important tool to combat schistosomiasis because of its practicality and applicability but should be applied with caution in low prevalence areas and in programs that aim to eliminate this disease. | Sergei Rodrigo Magalhaes de Sousa Isabelle Helena Lima Dias Alvaro Luan Santana Fonseca Bianca Rodrigues Contente Joyce Favacho Cardoso Nogueira Tatyellen Natasha da Costa Oliveira Stefan Michael Geiger Martin Johannes Enk | 2019 | Infectious Diseases of Poverty2019，8，3： | 1 |
| 4 | Experimental study on the effect of canyon cross wind on temperature distribution of buoyancy-induced smoke layer in tunnel fires显示文摘Experiments were conducted in a 1:20 arced tunnel model to investigate the effect of canyon cross wind on buoyancy induced smoke flow characteristics of pool fres,involving smoke movement behaviour and longitudinal temperature distribution of smoke layer.The canyon wind speed,longitudinal fre location and fre size were varied.Results show that there are two special smoke behaviours with the fre source positioned at different flow feld zones.When the fire source is positioned at the negative pressure zone,with increasing canyon wind speed,the smoke always exists upstream mainly due to the vortex,and the smoke temperature near the fire source increases frst and then decreases.However,when the fre source is located in the transition zone and the unidirectional flow zone,there is no smoke appearing upstream with a certain canyon wind speed.Meanwhile,the smoke temperature near the fre sources are decreases with increasing canyon wind speed.The dimensionless temperature rise of the smoke layer OT:*along the longitudinal direction of the tunnel follows a good exponential decay.As the canyon wind speed increases,the longitudinal decay rate of△T.*decreases.The longitudinal decay rate of AT*downstream of the fire is related to the fre location and canyon wind speed,and independent of the fire size.The empirical correlations for predicting the longitudinal decay of OT:*downstream of the fre are established.For a relatively large-scale fre,the longitudinal decay rate of AT:*upstream of the fire increases as the distance between the fire source and the upstream portal increases,especially for larger canyon wind speeds. | Chuangang Fan Liliang Yang Dia Luan Tao Chen Ao Jiao Richeng Ouyang Juan Wang Changkun Chen | 2021 | Transportation Safety and Environment2021，3，4： | 0 |
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