Seasonal studies of aquatic humic substances from Amazon rivers: characterization and interaction with Cu (II), Fe (II), and Al (III) using EEM-PARAFAC and 2D FTIR correlation analyses.

Aquatic humic substances (AHS) are defined as an important components of organic matter, being composed as small molecules in a supramolecular structure and can interact with metallic ions, thereby altering the bioavailability of these species. To better understand this behavior, AHS were extracted and characterized from Negro River, located near Manaus city and Carú River, that is situated in Itacoatiara city, an area experiencing increasing anthropogenic actions; both were characterized as blackwater rivers. The AHS were characterized by C nuclear magnetic ressonance and thermochemolysis GC-MS to obtain structural characteristics.

The Role of Pelvic Exenteration in Cervical Cancer: A Review of the Literature.

Pelvic exenteration represents a radical procedure aimed at achieving complete tumor resection with negative margins. Although it is the only therapeutic option for some cases of advanced tumors, it is associated with several perioperative complications. We believe that careful patient selection is related to better oncologic outcomes and lower complication rates.

Linking above and belowground carbon sequestration, soil organic matter properties, and soil health in Brazilian Atlantic Forest restoration.

Forest restoration mitigates climate change by removing CO and storing C in terrestrial ecosystems. However, incomplete information on C storage in restored tropical forests often fails to capture the ecosystem's holistic C dynamics. This study provides an integrated assessment of C storage in above to belowground subsystems, its consequences for greenhouse gas (GHG) fluxes, and the quantity, quality, and origin of soil organic matter (SOM) in restored Atlantic forests in Brazil.

Dissolved organic matter in bovine slaughterhouse wastewater using fluorescence spectroscopy associated with CP/PARAFAC and PCA methods.

In this work, we evaluated the potential application of fluorescence spectroscopy, associated with the canonical polyadic/parallel factor analysis and principal component analysis, to monitor the dissolved organic matter (DOM) generated from a slaughterhouse industry. During the monitoring process, we analyzed the residual water at the entrance and exit sites of the slaughterhouse effluent treatment as well as downstream and upstream the effluent receiving water body of a local river. The results revealed that the fluorescence analysis was able to identify proteins, chlorophylls, and humic substances at the entrance and exit sites of the slaughterhouse treatment plant and humic substances at the river water bodies.

Comparison of Sample Preparation Techniques for the (-)ESI-FT-ICR-MS Analysis of Humic and Fulvic Acids.

Soil organic matter (SOM) plays a key role in the global carbon and nitrogen cycles. Soil biogeochemistry is regularly studied by extracting the base-soluble fractions of SOM: acid-insoluble humic acid (HA) and acid-soluble fulvic acid (FA). Electrospray ionization-Fourier transform-ion cyclotron resonance-mass spectrometry (ESI-FT-ICR-MS) is commonly utilized for molecularly characterizing these fractions.