252 research outputs found
Micro-imaging VIS-IR spectroscopy of Martian meteorites in support of the future MaMIss spectrometer measurements
In the view of the future ExoMars 2020 mission, an activity of VIS-IR spectral investigations on terrestrial and extraterrestrial Mars Analogues is ongoing, in support of the Ma Miss in situ measurements. Ma_Miss is an imaging spectrometer that works in the range 0.4-2.2 ÎĽm with 20nm spectral sampling and that will observe the lateral wall of the borehole generated by ExoMars Rover's drill (Coradini et al., 2001). In this abstract, we describe some results about the spectral properties and characterization of mineral grains of the slabs of two Martian meteorites by means of the SPIM imaging spectrometer. SPIM works in the 0.22-5.05 ÎĽm spectral range, with a spatial resolution of 38x38 ÎĽm on the sample and represents the spare of the spectrometer on Dawn spacecraft (De Angelis et al., 2015). The meteorites investigated are North West Africa 8657 (NWA8657) and Dar Al Gani 489 (DAG489), basaltic shergottites. The average spectrum of the NWA8657 slab, in comparison with spectral measurements on other martian meteorites (Mcfadden & Cline, 2005) shows low reflectance values and 1 and 2 ÎĽm spectral absorptions indicating the strong presence of Ca-pyroxenes. The successive pixel by pixel analyses for the pyroxenes spectral speciation showed a great variability of clinopyroxenes in NWA8657. In fact, the 2 ÎĽm absorption at longer wavelength in some pixel does not always correspond to the 1 ÎĽm feature at longer wavelength. The average spectrum of DAG 489 is marked by a signature typical of low-Ca pyroxenes. Pixel by pixel analyses of DAG489 shows a more homogeneous composition of the pyroxenes characterized by the two major features centered at 0.98-0.99 and 1.98-2 ÎĽm. Further spectral absorptions related to sulfates, phosphates and carbonates were detected that are being validated by SEM-BSD to constrain the formation hystories of these two shergottites
Photobiomodulation by Near-Infrared 980-nm Wavelengths Regulates Pre-Osteoblast Proliferation and Viability through the PI3K/Akt/Bcl-2 Pathway
Background: bone tissue regeneration remains a current challenge. A growing body of evidence shows that mitochondrial dysfunction impairs osteogenesis and that this organelle may be the target for new therapeutic options. Current literature illustrates that red and near-infrared light can affect the key cellular pathways of all life forms through interactions with photoacceptors within the cells' mitochondria. The current study aims to provide an understanding of the mechanisms by which photobiomodulation (PBM) by 900-nm wavelengths can induce in vitro molecular changes in pre-osteoblasts.
Methods: The PubMed, Scopus, Cochrane, and Scholar databases were used. The manuscripts included in the narrative review were selected according to inclusion and exclusion criteria. The new experimental set-up was based on irradiation with a 980-nm laser and a hand-piece with a standard Gaussian and flat-top beam profile. MC3T3-E1 pre-osteoblasts were irradiated at 0.75, 0.45, and 0.20 W in continuous-wave emission mode for 60 s (spot-size 1 cm2) and allowed to generate a power density of 0.75, 0.45, and 0.20 W/cm2 and a fluence of 45, 27, and 12 J/cm2, respectively. The frequency of irradiation was once, three times (alternate days), or five times (every day) per week for two consecutive weeks. Differentiation, proliferation, and cell viability and their markers were investigated by immunoblotting, immunolabelling, fluorescein-FragELTM-DNA, Hoechst staining, and metabolic activity assays.
Results and conclusions: The 980-nm wavelength can photobiomodulate the pre-osteoblasts, regulating their metabolic schedule. The cellular signal activated by 45 J/cm2, 0.75 W and 0.75 W/cm2 consist of the PI3K/Akt/Bcl-2 pathway; differentiation markers were not affected, nor do other parameters seem to stimulate the cells. Our previous and present data consistently support the window effect of 980 nm, which has also been described in extracted mitochondria, through activation of signalling PI3K/Akt/Bcl-2 and cyclin family, while the Wnt and Smads 2/3-β-catenin pathway was induced by 55 J/cm2, 0.9 W and 0.9 W/cm
Tackling Inequalities in Oral Health: Bone Augmentation in Dental Surgery through the 3D Printing of Poly(ε-caprolactone) Combined with 20% Tricalcium Phosphate
Personalized medicine and overcoming healthcare inequalities have gained significant popularity in recent years. Polymers offer an ideal solution due to their cost-effectiveness, ease of customized 3D printing, and potential for wide-scale expansion. Poly- mers blended with β-tricalcium phosphate (TCP) have been found to synergize with the environ- mental tissues of maxillary bones and promote osteoconductivity. However, little is known about their properties after printing and their ability to maintain their biological role; additionally, limi- tations exist in 3D printing when high TPC concentrations are added. Our study demonstrated that poly ε-caprolactone (PCL)+β-TCP 20% composite can be successfully printed and is a suitable ma- terial for commercial 3D printing. The material also demonstrated biocompatibility, supporting osteoblast adhesion and promoting cell proliferation and differentiation. The composite can also sustain ISO14937:200935 sterilization procedures, which makes it an ideal material for printing medical devices that can be used by clinicians worldwide
Cytotoxic Potential of the Marine Diatom Thalassiosira rotula: Insights into Bioactivity of 24-Methylene Cholesterol
Marine microalgae are receiving great interest as sustainable sources of bioactive metabolites for health, nutrition and personal care. In the present study, a bioassay-guided screening allowed identifying an enriched fraction from SPE separation of the methanolic extract of the marine diatom Thalassiosira rotula with a chemically heterogeneous composition of cytotoxic molecules, including PUFAs, the terpene phytol, the carotenoid fucoxanthin and the phytosterol 24-methylene cholesterol (24-MChol). In particular, this latter was the object of deep investigation aimed to gain insight into the mechanisms of action activated in two tumour cell models recognised as resistant to chemical treatments, the breast MCF7 and the lung A549 cell lines. The results of our studies revealed that 24-MChol, in line with the most studied β-sitosterol (β-SIT), showed cytotoxic activity in a 3-30 µM range of concentration involving the induction of apoptosis and cell cycle arrest, although differences emerged between the two sterols and the two cancer systems when specific targets were investigated (caspase-3, caspase-9, FAS and TRAIL)
Influenza Virus Down-Modulates G6PD Expression and Activity to Induce Oxidative Stress and Promote Its Replication
none10no: Influenza virus infection induces oxidative stress in host cells by decreasing the intracellular content of glutathione (GSH) and increasing reactive oxygen species (ROS) level. Glucose-6-phosphate dehydrogenase (G6PD) is responsible for the production of reducing equivalents of nicotinamide adenine dinucleotide phosphate (NADPH) that is used to regenerate the reduced form of GSH, thus restoring redox homeostasis. Cells deficient in G6PD display elevated levels of ROS and an increased susceptibility to viral infection, although the consequences of G6PD modulation during viral infection remain to be elucidated. In this study, we demonstrated that influenza virus infection decreases G6PD expression and activity, resulting in an increase in oxidative stress and virus replication. Moreover, the down regulation of G6PD correlated with a decrease in the expression of nuclear factor erythroid 2-related factor 2 (NRF2), a key transcription factor that regulates the expression of the antioxidant response gene network. Also down-regulated in influenza virus infected cells was sirtuin 2 (SIRT2), a NADPH-dependent deacetylase involved in the regulation of G6PD activity. Acetylation of G6PD increased during influenza virus infection in a manner that was strictly dependent on SIRT2 expression. Furthermore, the use of a pharmacological activator of SIRT2 rescued GSH production and NRF2 expression, leading to decreased influenza virus replication. Overall, these data identify a novel strategy used by influenza virus to induce oxidative stress and to favor its replication in host cells. These observations furthermore suggest that manipulation of metabolic and oxidative stress pathways could define new therapeutic strategies to interfere with influenza virus infection.openDe Angelis, Marta; Amatore, Donatella; Checconi, Paola; Zevini, Alessandra; Fraternale, Alessandra; Magnani, Mauro; Hiscott, John; De Chiara, Giovanna; Palamara, Anna Teresa; Nencioni, LuciaDe Angelis, Marta; Amatore, Donatella; Checconi, Paola; Zevini, Alessandra; Fraternale, Alessandra; Magnani, Mauro; Hiscott, John; De Chiara, Giovanna; Palamara, Anna Teresa; Nencioni, Luci
Serum concentrations of perfluorinated alkyl substances in farmers living in areas affected by water contamination in the Veneto Region (Northern Italy)
Abstract Human exposure to per- and polyfluorinated alkyl substances (PFASs) is a major public health concern because in the last decades several cases of overexposure of people to PFASs, in particular through contaminated water, occurred worldwide. In 2013–2017 a PFAS drinking water contamination was discovered and investigated in northern Italy (Veneto region) and high PFAS serum levels were detected in exposed people. 629 subjects were enrolled: 257 residing in municipalities in the areas under impact, 250 residing in municipalities in areas at presumed background exposure and 122 farmers living in contaminated rural areas producing and consuming own livestock and vegetables and frequently using well water. The highest PFAS serum concentrations (median PFOA concentrations 40 ng/g) were found in the subgroup of farmers. The main factors influencing PFAS serum levels of farmers were residence area and the related extent of drinking water contamination, gender, years of residence in the municipalities, well water consumption and consumption of own produced food. PFOA serum concentrations in farmers residing in the areas of the Veneto region impacted by PFAS contamination are among the highest found worldwide
Investigation of Commiphora myrrha (Nees) Engl. oil and its main components for antiviral activity
The resinous exudate produced by Commiphora myrrha (Nees) Engl. is commonly known as true myrrh and has been used since antiquity for several medicinal applications. Hundreds of metabolites have been identified in the volatile component of myrrh so far, mainly sesquiterpenes. Although several efforts have been devoted to identifying these sesquiterpenes, the phytochemical analyses have been performed by gas-chromatography/mass spectrometry (GC–MS) where the high temperature employed can promote degradation of the components. In this work, we report the extraction of C. myrrha by supercritical CO2, an extraction method known for the mild extraction conditions that allow avoiding undesired chemical reactions during the process. In addition, the analyses of myrrh oil and of its metabolites were performed by HPLC and GC–MS. Moreover, we evaluated the antiviral activity against influenza A virus of the myrrh extracts, that was possible to appreciate after the addition of vitamin E acetate (α-tocopheryl acetate) to the extract. Further, the single main bioactive components of the oil of C. myrrha commercially available were tested. Interestingly, we found that both furanodienone and curzerene affect viral replication by acting on different steps of the virus life cycle
Wound Healing: In Vitro and In Vivo Evaluation of a Bio-Functionalized Scaffold Based on Hyaluronic Acid and Platelet-Rich Plasma in Chronic Ulcers
Chronic ulcers are characterized by loss of substance without a normal tendency towards spontaneous healing. The Wound Bed Preparation Guideline advises that after diagnosis, the expert should correct the biological state of the ulcer micro-environment based on TIME principles (Tissue, Infection, Moisture balance, Epidermal). There are many ways to treat such ulcers, for example through use of advanced dressings, negative pressure, surgical toilets, dermal substitutes, autologous skin grafting, and free or local flaps. In vitro and in vivo pre-clinical models hold widely acknowledged potential yet complex limitations. Tissue bioengineering could be an ideal approach to foster innovative strategies in wound healing. Our observational study reports on an in vitro and in vivo evaluation of a bio-functionalized scaffold composed of platelet-rich plasma (PRP) and hyaluronic acid (HA) used in 182 patients affected by chronic ulcers (diabetic and vascular), comparing the results with a control group of 182 patients treated with traditional dressings (HA alone). After 30 days the patients who had undergone the combined treatment (PRP + HA), showed 96.8% +/- 1.5% re-epithelialization, as compared to 78.4% +/- 4.4% in the control group (HA only). Within 80 days, they had 98.4% +/- 1.3% re-epithelialization as compared to 87.8% +/- 4.1% in the control group (HA only; p < 0.05). No local recurrence was observed during the follow-up period. PRP + HA treatment showed stronger regenerative potential in terms of epidermal proliferation and dermal renewal compared with HA alone
Ion-exchanged glass microrods for SERS detection of DNA
Different chemical or physical deposition processes have been previously proposed to equip surfaces with a layer of plasmonic NPs to produce effective SERS responses. Here, we present a SERS biosensor obtained by an ion-exchange process in soda-lime glass microrods for efficient DNA detection
A SERS affinity bioassay based on ion-exchanged glass microrods
14noThe well-known enhancement effect of surface-enhanced Raman spectroscopy (SERS) is associated with the presence of metallic nanostructures at the substrate surface. Different bottom-up and top-down processes have been proposed to impart the substrate with such a nanostructured layer. The former approaches are low cost but may suffer from reusability and stability. The latter strategies are expensive, time consuming and require special equipment that complicate the fabrication process. Here, we present the possibility to obtain stable and reusable SERS substrates by a low-cost silver-sodium ion-exchange process in soda-lime glass microrods. The microrods were obtained by cutting the tip of the ion-exchanged soda-lime fiber, resulting in disks of about few millimeters in length and one hundred microns in diameter. A thermal annealing post-process was applied to trigger the reduction of Ag+ ions into nanoparticles (AgNPs) within the ion-exchanged glass microrods. Afterwards, ion-exchange and thermal treatments were carefully tuned to assure the presence of silver NPs exposed on the surface of the microrods, without using any chemical etching. An AFM analysis confirmed the presence of AgNPs with size of tens of nm on the surface of the fiber probe. A SERS affinity bioassay was developed on the probe with the final aim of detecting microRNA fragments acting as biomarkers of different diseases. Specifically a DNA hybridization assay was built up by anchoring a molecular beacon containing a Raman tag on the Ag surface via thiol chemistry. Initial SERS experiments confirmed the presence of the beacon on the NPs embedded on the microrods surface, as monitored by detecting main spectral bands ascribed to the oligonucleotide chain. Finally, the ability of the platform to interact with the target microRNA sequence was assessed. The analysis was repeated on a number of miRNA sequences differing from the target to evaluate the specificity of the proposed assay.openopenBerneschi, Simone; D'Andrea, Cristiano; Giannetti, Ambra; De Angelis, Marella; Banchelli, Martina; Barucci, Andrea; Boetti, Nadia Giovanna; Pelli, Stefano; Baldini, Francesco; Pini, Roberto; Janner, Davide; Pugliese, Diego; Milanese, Daniel; Matteini, PaoloBerneschi, Simone; D'Andrea, Cristiano; Giannetti, Ambra; De Angelis, Marella; Banchelli, Martina; Barucci, Andrea; Boetti, Nadia Giovanna; Pelli, Stefano; Baldini, Francesco; Pini, Roberto; Janner, Davide; Pugliese, Diego; Milanese, Daniel; Matteini, Paol
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