Environmental radioactivity studies have been allowed establishing radiometric patterns in several area of the earth's crust. The work was conducted through radiometric analyses of regions with high levels of radionuclides and others with no history of anomalies. The research allowed establishing the radiometric profile of soils in the state of Pernambuco, Brazil, using a gamma spectrometry system. The specific activities ranged from 16.5 to 287.5 Bq kg-1 for 238U, 2.0 to 191.7 Bq kg-1 for 226Ra, 1.3 to 281.4 Bq kg-1 for 232Th and from 5.0 to 2600.9 Bq kg-1 for 40K. The results showed areas with low levels of ionizing radiation. However, for 40K some points presented high values, although non-representative of the number of samples investigated. The 226Ra/238U and 232Th/238U ratios allowed to determine the radioactive imbalance condition and to obtain information about aspects of soil availability providing an assessment of the dynamics of these radionuclides.
INTRODUCTION: Azole resistance in Aspergillus fumigatus constitutes an emergency health problem, and the rapid and reliable characterization of this pathogen is essential to guide the appropriate antifungal therapy, techniques based on mass spectrometry, in these cases, could reduce the time of diagnosis in comparison to traditional methods used in hospital routine, with this we intend to establish a protocol to determine the antifungal susceptibility by MALDI TOF MS of Aspergillus fumigatus isolates and correlated with the CLSI guideline. METHODS: Sixteen Aspergillus fumigatus stored at the URM Culture Collection (Brazil) and another at Nantes University (France) were evaluated by the microdilution method in reference broth against itraconazole and voriconazole and the MALDI-TOF MS was used to identify the minimum concentration of change of the protein profile after exposure to the antifungal, the spectra obtained against each concentration were applied to generate composite correlation index (CCI) matrices for each filamentous isolate individually and used to generate heat maps and virtual gel. RESULTS: In this work, the minimum inhibitory concentration by CLSI and the minimum profile change concentration by MALDI-TOF, showed an agreement of 88.2% and 82.4% for itraconazole and voriconazole, respectively. CONCLUSIONS: MALDI-TOF MS is able to determine the cutoff point of susceptibility for Aspergillus fumigatus and allows to predict the best choice of antifungal for patients with invasive aspergillosis.
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