Publications by authors named "Olga Carreira"

Objectives: The performance of a new point-of-care CE-IVD-marked isothermal lab-on-phone COVID-19 assay was assessed in comparison to a gold standard real-time reverse transcriptase-PCR method.

Methods: The study was conducted following a nonprobability sampling of ≥16-year-old volunteers from three different laboratories, using direct mouthwash (N = 24) or nasopharyngeal (N = 191) clinical samples.

Results: The assay demonstrated 95.

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Context: Colonoscopy is essential for synchronous and metachronous cancer detection. Carcinoembryonic antigen is a colorectal cancer tumor marker, important as a follow-up tool in patients with previous colorectal cancer. False-positive carcinoembryonic antigen elevation results in multiples exams and in patient anxiety.

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Time-of-flight secondary ion mass spectrometry was used to study four human calculi and to compare the results with those from twelve commercially available urinary calculi minerals including three organic compounds (L-cystine, uric acid and sodium urate). Phase identification of calcium phosphate compounds was carried out by considering the relative ion abundances of [Ca(2)O](+) and [CaPO(2)](+). Deprotonated [M-H](-) and protonated [M+H](+) uric acid were detected and used for component recognition in pure uric acid and in the mixed samples of struvite, calcium oxalate and uric acid.

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