STUDY ON ANALYTICAL PERFORMANCE OF LOW-POWERED ArMPT-AES

In this paper the analytical performance of the low-powered Ar microwave plasma torch atomic emission spectrometry(MPT-AES) was studied.The experimental results indicate that the analytical performance of low-powered ArMPT-AES is satisfactory.

Applying Analytical Hierarchy Process to a WiMAX Performance Evaluation Model

Evaluating performance of individual features of WiMAX technology is a topic of widespread discussion. Currently, there is no quantitative way of measuring WiMAX technology so that wireless operators can meet their design objectives. This paper outlines a set of design criteria for WiMAX and provides a decision-making aid that ranks the importance of criteria using Analytic Hierarchy Process （AHP）. This ranking should sufficiently reflect market expectations of the relative importance of various design criteria. A model integrating AHP priorities with enhanced Data Envelopment Analysis （DEA） is the basis for formulating a technological value in simple, comparable format. A case study is provided to show how this technological value is used to evaluate a three year network deployment plan. In the future, this model could be extended to WiMAX equipment suppliers for the purpose of validating performance targets of individual criteria, and enhancing supplier roadmaps for future network development.

Assessment of Rapid Diagnostic Tests Algorithms in Transfusion Medicine Setting

Background: The rapid diagnostic tests play a pivotal role in the screening of viral markers in blood qualification for transfusion in limited resource setting. Therefore, it is important to assess their analytical performances to ensure their proper functioning. Material and Methods: We performed a cross- sectional study by successive recruitment to assess the diagnostic value of rapid diagnostic tests algorithms using ELISA as a reference test. A total of 661 blood from donors were enrolled for this study. Rapid Diagnostic Tests (RDTs) and ELISA tests were performed for each sample by a couple of double-blinded biotechnologists. Data were collected on case report form and captured in Microsoft Excel then the file was imported and analyzed using R software version 4.0.3. Results: The diagnostic accuracy for the algorithms are summarized in Table 1. For HIV-algorithm, the internal validity parameters were as follow: sensitivity (sens) 99.0% (95% CI = 97.8, 99.5);specificity (spec) 98.3% (95% CI = 90.9, 99.7);positive likelihood ratio (PLR) 57.4 (95% CI = 8.2, 401.0);negative likelihood ratio (NLR) 0.01 (95% CI = 0.0005, 0.02);diagnostic odd ratio (DOR) 4710. HBV-Ag/Ab RDTs achieve the following diagnostic accuracy: sens 99.7% (95% CI = 98.3, 99.9);spec 98.8% (95% CI = 96.9, 95.5);PLR 81.8 (95% CI = 30.9, 217.0);NLR 0.003 (95% CI = 0.0004, 0.02);DOR 14,110. The analytical performances of HCV-Ab RDTs were as follow: sens 98.7% (95% CI = 97.5, 99.4);spec 93.1% (95% CI = 78.0, 98.1);PLR 14.3 (95% CI = 3.8, 54.5);NLR 1.5 (95% CI = 0.8, 2.8);DOR 962.6. The parameters evaluating the external validity of RDTs screening for the three viral markers when the theorical prevalence was < 5% are summarized in Figure 3. At the prevalence < 5%, the NPV of the three RDTs were 99.96%, 99.99% and 99.94%. At the same prevalence, we found the following Positive Predictive Values (PPV) 70.82%, 77.59% and 37.35% for HIV-Ag/Ab RDTs, HBV-Ag RDTs and HCV-Ab RDTs algorithms, respectively. The overall areas under the received operating characteristic (ROC) curves were 98.6%, 99.2% and 99.2%;95.9% for HIV-Ag/Ab RDTs, HBV-Ag RDTs and HCV-Ab RDTs algorithms, respectively. Conclusion: RDTs algorithms can play a pivotal role in the screening of HIV-Ab/Ag, HBs-Ag in the setting of resources limited-countries where financial and technical expertise shortages are a standard fare. However, their use for diagnostic purposes must be done with great caution and the result must necessarily be confirmed with an ELISA or molecular technique particularly for HCV-RDTs algorithm which achieved an NLR value > 0.1.

Study on parameters influencing analytical performance of laser-induced breakdown spectroscopy

Lens-to-sample distances, delay time, atmospheric condition, laser pulse energy, etc. had obvious effects on the analytical performance of laser-induced breakdown spectroscopy. In this paper, these parameters are investigated in greater detail and we will explain how they have influences on the analytical performance. The results show that the focal plane under the sample surface can improve precision and detection limit, and the delay time should be decided according to sensitivity and accuracy. Spectral line intensity is stronger in argon than helium, nitrogen and air gas environment. Pulse energy should exceed energy threshold （about 50 m J） which can generate plasma, and the energy should not exceed about 300 mJ to avoid plasma shielding. Under optimum parameters, concentration relative standard deviation of C, Si, Mn, P, S, Ni, and Cr for low-alloyed steel （sample number 11278） which were measured 11 times is 2.37%, 2.18%, 2.23%, 7.8%, 9.34%, 1.92%, and 2.13%, respectively. And the detection limit of C, Si, Mn, P, S, Ni, and Cr for pure steel is 0.0045%, 0.0072%, 0.0069%, 0.0027%, 0.0024%, 0.0047%, and 0.0024%, respectively.