Gold-Nanoparticle-Based Colorimetric Discrimination of Cancer-Related Point Mutations with Picomolar Sensitivity

Point mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene are being increasingly recognized as important diagnostic and prognostic markers in cancer. In this work, we describe a rapid and low-cost method for the naked-eye detection of cancer-related point mutations in KRAS based on gold nanoparticles. This simple colorimetric assay is sensitive (limit of detection in the low picomolar range), instrument-free, and employs nonstringent room temperature conditions due to a combination of DNA-conjugated gold nanoparticles, a probe design which exploits cooperative hybridization for increased binding affinity, and signal enhancement on the surface of magnetic beads. Additionally, the scheme is suitable for point-of-care applications, as it combines naked-eye detection, small sample volumes, and isothermal (PCR-free) amplification

Paleoenvironmental changes related to the variations of the sea-ice cover during the Late Holocene in an Antarctic fjord (Edisto Inlet, Ross Sea) inferred by foraminiferal association

TR17-08, a marine sedimentary core (14.6 m), was collected during 2017 from the Edisto Inlet (Ross Sea, Antarctica), a small fjord near Cape Hallett. The core is characterized by expanded laminated sedimentary sequences making it suitable for studying submillennial processes during the Early Holocene. By studying different well-known foraminifera species (Globocassidulina biora, G. subglobosa, Trifarina angulosa, Nonionella iridea, Epistominella exigua, Stainforthia feylingi, Miliammina arenacea, Paratrochammina bartrami and Portatrochammina antarctica), we were able to identify five different foraminiferal assemblages over the last 2000 years BP. Comparison with diatom assemblages and other geochemical proxies retrieved from nearby sediment cores in the Edisto Inlet (BAY05-20 and HLF17-1) made it possible to distinguish three different phases characterized by different environmental settings: (1) a seasonal phase (from 2012 to 1486 years BP) characterized by the dominance of calcareous species, indicating a seasonal opening of the inlet by more frequent events of melting of the sea-ice cover during the austral summer and, in general, a higher-productivity, more open and energetic environment; (2) a transitional phase (from 1486 to 696 years BP) during which the fjord experienced less extensive sea-ice melting, enhanced oxygen-poor conditions and carbonate dissolution conditions, indicated by the shifts from calcareous-dominated association to agglutinated-dominated association probably due to a freshwater input from the retreat of three local glaciers at the start of this period; and (3) a cooler phase (from 696 years BP to present) during which the sedimentation rate decreased and few to no foraminiferal specimens were present, indicating ephemeral openings or a more prolonged cover of the sea ice during the austral summer, affecting the nutrient supply and the sedimentation regime

Resolving sea ice dynamics in the north-western Ross Sea during the last 2.6 ka: From seasonal to millennial timescales

12 months embargo applie

Alterazioni dei parametri vitali indotte dalle cure igieniche nel paziente critico: uno studio esplorativo

Le cure igieniche effettuate nel paziente critico possono indurre modificazioni dei parametri vitali. Obiettivo. Rilevare le variazioni dei parametri vitali nel paziente critico durante le cure igieniche e le variazioni a manovre concluse, rispetto al valore basale. Metodo. Sono stati osservati i parametri vitali di 6 pazienti in 10 giorni di degenza pre-cure igieniche (ore 06.00), durante le cure igieniche (ore 08.00) e a 90 minuti dal termine (ore 10.00). Risultati. Sia durante le cure igieniche, sia a due ore dalla fine vi è una modificazione dei parametri del paziente: Frequenza cardiaca +11.20%/+1.48 (aumento medio/differenza media a 2 ore rispetto ai valori basali), Pressione arteriosa sistolica +22.68/+1.56, Saturimetria capillare arteriosa -4.31/+0,27, Frequenza respiratoria +8.10/+2.66, Volume corrente +4.04/-7.51, Volume di CO2 prodotta al minuto +5,34/-22.33, Temperatura Vescicale -0,85/-0,60. Conclusioni. Le cure igieniche nel paziente critico inducono modificazioni rilevanti dei parametri vitali. In questa fase è fondamentale mantenere il monitoraggio emodinamico e respiratorio e applicare protocolli per la gestione della sedazione e del supporto farmacologico vasoattivo

Foraminiferal assemblage over the last 2000 years in Edisto Inlet (Ross Sea, Victoria Land Coast, Antarctica) and their palaeoenvironmental significance

The marine sediment core TR17 08 (14.6m), was collected in Edisto Inlet (Ross Sea, Antarctica) during the 2017 Italian oceanographic campaign. The core is composed by laminated sedimentary sequences, making it suitable for studying submillennial processes. We focused on nine common Foraminifera species from the Southern Ocean, both benthic and planktonic. By the comparison between other proxies retrieved from nearby sediment cores (Fig. 6), we were able to distinguish three different environmental phases over the last 2000 yrs (6.5m). The seasonal phase (2012 1486 yrs BP) is characterized by the dominance of calcareous species, indicating a seasonal melting of the sea-ice cover. This led to high productivity and a more open and energetic environment, with possible intrusion of warmerwater masses. During the transitional phase (1486 696 yrs BP) the shift from a calcareous dominated association to an agglutinated dominated one suggests a hypoxic environment with high carbonate dissolution condition and high residency time of the water masses. This can be hypothesized to be derived from a freshwater input derived from the retreat of the local glaciers, coherent with other glaciological studies of the region. During the final cold phase (696 yrs BP present) the sedimentation rate decrease and few foraminiferal specimens are present, thus indicating ephemeral openings or a more prolonged cover of the sea ice during the summer. In addition, despite the hypothesized absence of echinoderm remains in the Southern Ocean due to fast dissolution rate of carbonate, we were able to identify an ophiuroid species and confirm the presence of irregular echinoids. Significant differences regarding the presence/absence of these two groups with respect to the foraminiferal assemblages were detected. This study shows the usefulness of calcareous microfossils in cold marine environments and hints a yet unexplored potential of echinoderm remains as a palaeoceanographic proxy in such regime

Gold-Nanoparticle-Based Colorimetric Discrimination of Cancer-Related Point Mutations with Picomolar Sensitivity

Point mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene are being increasingly recognized as important diagnostic and prognostic markers in cancer. In this work, we describe a rapid and low-cost method for the naked-eye detection of cancer-related point mutations in KRAS based on gold nanoparticles. This simple colorimetric assay is sensitive (limit of detection in the low picomolar range), instrument-free, and employs nonstringent room temperature conditions due to a combination of DNA-conjugated gold nanoparticles, a probe design which exploits cooperative hybridization for increased binding affinity, and signal enhancement on the surface of magnetic beads. Additionally, the scheme is suitable for point-of-care applications, as it combines naked-eye detection, small sample volumes, and isothermal (PCR-free) amplification

Keratin-hydrotalcites hybrid films for drug delivery applications

In this work novel hybrid materials for drug delivery purposes are obtained by combining keratin with hydrotalcite nanoparticles containing diclofenac. The hybrid films showed a less pronounced swelling, porosity and degradation and a greater thermal stability compared to pure keratin films containing free diclofenac. These results, together with the slight shift towards smaller wavelength numbers of amide I band led to the hypothesis of a probable cross-linking between hydrotalcites and the protein mediated by glutaraldehyde, which results in a total reinforcing action on the hybrid material. In addition, diclofenac release profiles of the hybrid film in physiological conditions were higher than those of the non-hybrid compound. Furthermore, keratin/hydrotalcite were able to support fibroblast cells adhesion and growth suggesting their potential use as drug delivery systems for wound healing and tissue engineering application