Marcus Vinícius Mazega Figueredo

Dr. Marcus Vinícius Mazega Figueredo


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 April 2023 in Diagnostics
Verified
Journal Article
Open access
PDF file
BRBruna Winkert Raddatz
Bruna Winkert Raddatz
FRFelipe Jansen Rabello
Felipe Jansen Rabello
RBRafael Benedetti
Rafael Benedetti
GSGisleine J Steil
Gisleine J Steil
LILouise Matiê Imamura
Louise Matiê Imamura
MFMarcus Vinícius Mazega Figueredo
Marcus Vinícius Mazega Figueredo
Quick and reliable mass testing of infected people is an effective tool for the contingency of SARS-CoV-2. During the COVID-19 pandemic, Point-of-Care (POC) tests using Loop-Mediated Isothermal Amplification (LAMP) arose as a useful diagnostic tool. LAMP tests are a robust and fast alternative to Polymerase Chain Reaction (PCR), and their isothermal property allows easy incorporation into POC platforms. The main drawback of using colorimetric LAMP is the reported short-term stability of the pre-mixed reagents, as well as the relatively high rate of false-positive results. Also, low-magnitude amplification can produce a subtle color change, making it difficult to discern a positive reaction. This paper presents Hilab Molecular, a portable device that uses the Internet of Things and Artificial Intelligence to pre-analyze colorimetric data. In addition, we established manufacturing procedures to increase the stability of colorimetric RT-LAMP tests. We show that ready-to-use reactions can be stored for up to 120 days at −20 °C. Furthermore, we validated both the Hilab Molecular device and the Hilab RT-LAMP test for SARS-CoV-2 using 581 patient samples without any purification steps. We achieved a sensitivity of 92.93% and specificity of 99.42% (samples with CT ≤ 30) when compared to RT-qPCR.

11 May 2023 in Diagnostics
Verified
Journal Article
Open access
PDF file
AGAléxia Thamara Gasparin
Aléxia Thamara Gasparin
CAClaudiane Isabel Franco Araujo
Claudiane Isabel Franco Araujo
MCMônica Ribas Cardoso
Mônica Ribas Cardoso
PSPatricia Schmitt
Patricia Schmitt
Juliana Beker GodoyJuliana Beker Godoy
Juliana Beker Godoy
MFMarcus Vinícius Mazega Figueredo
Marcus Vinícius Mazega Figueredo
The complete blood count (CBC) is a highly requested test that is generally restricted to centralized laboratories, which are limited by high cost, being maintenance-demanding, and requiring costly equipment. The Hilab System (HS) is a small, handheld hematological platform that uses microscopy and chromatography techniques, combined with machine learning (ML) and artificial intelligence (AI), to perform a CBC test. This platform uses ML and AI techniques to add higher accuracy and reliability to the results besides allowing for faster reporting. For clinical and flagging capability evaluation of the handheld device, the study analyzed 550 blood samples of patients from a reference institution for oncological diseases. The clinical analysis encompassed the data comparison between the Hilab System and a conventional hematological analyzer (Sysmex XE-2100) for all CBC analytes. The flagging capability study compared the microscopic findings from the Hilab System and the standard blood smear evaluation method. The study also assessed the sample collection source (venous or capillary) influences. The Pearson correlation, Student t-test, Bland–Altman, and Passing–Bablok plot of analytes were calculated and are shown. Data from both methodologies were similar (p > 0.05; r ≥ 0.9 for most parameters) for all CBC analytes and flagging parameters. Venous and capillary samples did not differ statistically (p > 0.05). The study indicates that the Hilab System provides humanized blood collection associated with fast and accurate data, essential features for patient wellbeing and quick physician decision making.

10 June 2024 in Sensors
Verified
Journal Article
Open access
PDF file
Ava GevaerdAva Gevaerd
Ava Gevaerd
ECEmmanuelle Carneiro
Emmanuelle Carneiro
JGJeferson L. Gogola
Jeferson L. Gogola
Diego Rinaldi Pavesi NicolleteDiego Rinaldi Pavesi Nicollete
Diego Rinaldi Pavesi Nicollete
ESErika Bergamo Santiago
Erika Bergamo Santiago
MFMarcus Vinícius Mazega Figueredo
Marcus Vinícius Mazega Figueredo
This paper reports a rapid and sensitive sensor for the detection and quantification of the COVID-19 N-protein (N-PROT) via an electrochemical mechanism. Single-frequency electrochemical impedance spectroscopy was used as a transduction method for real-time measurement of the N-PROT in an immunosensor system based on gold-conjugate-modified carbon screen-printed electrodes (Cov-Ag-SPE). The system presents high selectivity attained through an optimal stimulation signal composed of a 0.0 V DC potential and 10 mV RMS−1 AC signal at 100 Hz over 300 s. The Cov-Ag-SPE showed a log response toward N-PROT detection at concentrations from 1.0 ng mL−1 to 10.0 μg mL−1, with a 0.977 correlation coefficient for the phase (θ) variation. An ML-based approach could be created using some aspects observed from the positive and negative samples; hence, it was possible to classify 252 samples, reaching 83.0, 96.2 and 91.3% sensitivity, specificity, and accuracy, respectively, with confidence intervals (CI) ranging from 73.0 to 100.0%. Because impedance spectroscopy measurements can be performed with low-cost portable instruments, the immunosensor proposed here can be applied in point-of-care diagnostics for mass testing, even in places with limited resources, as an alternative to the common diagnostics methods.

1 January 2023
Verified
Conference Paper
Open access
PDF file
RBRafael Benedetti
Rafael Benedetti
FBFrieda Saicla Barros
Frieda Saicla Barros
DNDiego Rinaldi Pavesi Nicollete
Diego Rinaldi Pavesi Nicollete
MFMarcus Vinícius Mazega Figueredo
Marcus Vinícius Mazega Figueredo
Bilirubin is a pigment metabolite that serves as a liver marker. Could be used to evaluate liver function. This metabolite is coming from Red blood cell degradation, associated with direct liver damag