Green Synthesis of Silver Nanoparticles Using Pecan Nut (<i>Carya illinoinensis</i>) Shell Extracts and Evaluation of Their Antimicrobial Activity

Nowadays, the increase in bacteria resistant to multiple antibiotics has become a real threat to the human health, forcing researchers to develop new strategies. Silver nanoparticles (AgNPs) may be a viable solution to this problem. The green synthesis of AgNPs is considered a green, ecological and low-priced process that provides small and biocompatible nanostructures with antimicrobial activity with a potential application in medicine. In this work, pecan nut shell extracts were analyzed in order to determine their viability for the production of AgNPs. These NPs were synthesized using an extract rich in bioactive molecules, varying the reaction time and silver nitrate (AgNO3) concentration. AgNPs production was confirmed by FT-IR, UV-Vis and EDX spectroscopy, while their morphology and size were determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The antibacterial activity of AgNPs was evaluated by the agar diffusion method against Salmonella typhi, Staphylococcus aureus and Proteus mirabilis. The results showed that it is possible to obtain nanoparticles from an extract rich in antioxidant molecules with a size between 39.9 and 98.3 nm with a semi-spherical morphology. In addition, it was shown that the reaction time and the concentration of the precursor influence the final nanoparticles size. Antimicrobial tests showed that there is greater antimicrobial inhibition against Gram-negative than Gram-positive microorganisms, obtaining inhibition zone from 0.67 to 5.67 mm

Organic matter bioavailability in tropical coastal waters: The Great Barrier Reef

21 pages, 7 tables, 5 tablesThe bioavailability of organic matter (OM) was assessed at three locations during the dry and wet seasons in the Great Barrier Reef (GBR), by measuring changes in particulate organic matter (POM) and dissolved organic matter (DOM) concentrations during laboratory incubations over 50 d. The sites did not show any difference in salinity and, therefore, observed changes could be related to factors such as disparities in the biological activity and/or the impact of sediment resuspension rather than to location. Our results demonstrate that the POM pool has a higher bioavailability than the DOM pool, with the C, N, and P-containing compounds being more bioavailable than the C and N-containing molecules, which in turn are more labile than compounds containing just C. The addition of labile POM to the DOM pool did not impact the bioavailability of DOM, suggesting that priming had no major impact on the degradation of this pool in these experiments. Furthermore, our results demonstrate that 94% and 75% of the bioavailable N and P are contained in the organic fraction delivering enough nutrients to sustain phytoplankton productivity in the GBR. Using the obtained degradation rate constants and an average water residence time of 2 weeks, we show that most bioavailable POM (> 96%) and DOM (> 83%) is degraded before reaching the outer shelf. Our results emphasize that OM is a key and mostly unaccounted part of the C, N, and P cycles in tropical coastal waters of the GBRThe field data included in the manuscript was obtained with support from the Great Barrier Reef Marine Park Authority, through funding from the Australian Government Reef Program and from the Australian Institute of Marine Science. X. A. A. S was support by the CSIC project FOMEM (grant PIE 201030E130). Financial support for this study was provided by the Australian Institute of Marine Science. Thanks are due for the financial support to CESAM (UID/AMB/50017 - POCI-01-0145-FEDER- 007638), to FCT/MEC through national funds, to the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020Peer reviewe

Outcomes in Neurosurgical Patients Who Develop Venous Thromboembolism

International audienceOBJECTIVES: Registro Informatizado de Enfermedad TromboEmbólica (RIETE) database was used to investigate whether neurosurgical patients with venous thromboembolism (VTE) were more likely to die of bleeding or VTE and the influence of anticoagulation on these outcomes.METHODS:Clinical characteristics, treatment details, and 3-month outcomes were assessed in those who developed VTE after neurosurgery.RESULTS: Of 40 663 patients enrolled, 392 (0.96%) had VTE in less than 60 days after neurosurgery. Most patients in the cohort (89%) received initial therapy with low-molecular-weight heparin, (33% received subtherapeutic doses). In the first week, 10 (2.6%) patients died (8 with pulmonary embolism [PE], no bleeding deaths; P = .005). After the first week, 20 (5.1%) patients died (2 with fatal bleeding, none from PE). Overall, this cohort was more likely to develop a fatal PE than a fatal bleed (8 vs 2 deaths, P = .058).CONCLUSIONS: Neurosurgical patients developing VTE were more likely to die from PE than from bleeding in the first week, despite anticoagulation