Performance verification of four nucleic acid detection systems: A comparitve study / 中国输血杂志

【Objective】 To compare the analytical performance of Tigris, Panther, ChiTaS BSS1200 and cobas S201 system to see if they satisfy the requirements of blood screening and to know the concordance of the results presented by these four systems. 【Methods】 According to the relevant documents of ISO15189 and Standard Operating Procedure of Blood Station(2019), the parameters needed to be verified for nucleic acid tests(NAT) included: analytical sensitivity verification, system compare test, anti-jamming capability and anti-cross-contamination ability. 【Results】 The 95% detection limits of Tigris, Panther, ChiTaS BSS1200 and Cobas S201 for HBV-DNA(IU/mL), HIV-RNA(IU/mL) and HCV-RNA(IU/mL) were 2.013 vs 4 vs 2.995 vs 0.99, 13.039 vs 10.21 vs 30.952 vs 32.24, and 2.278 vs 2.077 vs 12.008 vs 3.39, respectively. In the performance comparison verification between NAT systems, the results of the two sets of Tigris systems were in full accordance with serum plate, with a concordance rate of 100%, Kappa value of 1, and none cross-contamination.The concordance rate of No.1 Panther system was 100%, and No.2 98%, with Kappa value of 0.961 and none cross-contamination. Hemolytic samples (5g/L Hb concentration) and lipemic blood samples (13.81 mmol/L TG concentration) had no significant effect on the detection of low-concentration samples. 【Conclusion】 No significant differences in the performance of NAT systems were notable by devices, as the four systems were fully automated with high sensitivity, which can fully satisfy the blood screening requirements. Panther system demonstrates superior analysis sensitivity in HCV-RNA/HIV-RNA and lower in HBV DNA, but also in required criteria, as compared to Tigris system. Neither hemolysis nor lipemic blood had any significant effect on the test results.

Definição de zonas de manejo a partir de mapas de condutividade elétrica e matéria orgânica / Definition of management zones from maps of electrical conductivity and organic matter

Este trabalho teve por objetivo definir zonas de manejo com base na variabilidade espacial da condutividade elétrica aparente do solo e da matéria orgânica, em áreas de plantio direto de milho e soja. Para caracterizar a variabilidade espacial foram utilizados métodos geoestatísticos. Comprovada a dependência espacial foram elaborados os mapas temáticos, por meio da krigagem. Para delimitação das zonas de manejo a partir dos mapas de variabilidade interpolados foi utilizado o algoritmo fuzzi K-means e para definição do número ótimo de classes foi determinado o índice de perfomance fuzzi e entropia da partição modificada. As variáveis utilizadas para a definição das zonas de manejo foram a altitude, a condutividade elétrica a 20 cm e 40 cm de profundidade e a matéria orgânica. A partir destas variáveis foram gerados sete mapas de zonas de manejo, e posteriormente pelo teste de Kappa foi analisada a concordância entre os mapas gerados pelas zonas de manejo e os mapas das propriedades físico-químicas do solo. Como resultado verificou-se o valor ótimo de número de classes igual a dois. Os melhores resultados na classificação das zonas de manejo, para os atributos referentes a textura do solo são observados a partir de mapas de matéria orgânica ou de condutividade elétrica e, para os atributos químicos, a partir de mapas de matéria orgânica ou de altitude e matéria orgânica. As zonas de manejo definidas a partir da condutividade elétrica a 20 cm permitiram detectar diferenças significativas entre as médias de produtividade de soja.

This study aimed to define management zones based on spatial variability of soil apparent electrical conductivity and organic matter in areas of tillage. To characterize the spatial geostatistical methods were used. Proven spatial dependence was prepared thematic maps through kriging. For delineation of management zones based on maps of variability was interpolated using the Fuzzy K-means algorithm and to define the optimal number of classes was determined Fuzzy performance index and entropy of the partition changed. The variables used for defining management zones were altitude, the electrical conductivity at 20 cm and 40 cm depth and organic matter. From these seven variables were generated maps of management zones, and later by the Kappa test was analyzed the correlation between the maps generated by the management zones and maps of the physical and chemical properties of soil. As a result there was an optimum number of classes equal to two, with the attributes related to soil texture management zone maps from organic matter or electrical conductivity and the chemical zone management from maps of organic matter or organic matter and altitude showed better results in their classification. The management zones defined from the electrical conductivity at 20 cm allowed us to detect significant differences between the average yield of soybean.

Discrimination and explanation of statistical errors in the analysis of qualitative data / 基础医学与临床

In this paper,many examples of misusing statistics analyzing the qualitative data are unveiled.Obviously,it is extremely important for people to process the qualitative data correctly by checking the types of contingency tables and the preconditions of data.