1,722,911 research outputs found
On the methods of evaluation of the apparent resistivity under conditions of low message-to-noise ratio
No full textThe Hybrid Nano-Biointerface between Proteins/Peptides and Two-Dimensional Nanomaterials
Full text linkIn typical protein-nanoparticle surface interactions, the biomolecule surface binding and consequent conformational changes are intermingled with each other and are pivotal to the multiple functional properties of the resulting hybrid bioengineered nanomaterial. In this review, we focus on the peculiar properties of the layer formed when biomolecules, especially proteins and peptides, face two-dimensional (2D) nanomaterials, to provide an overview of the state-of-the-art knowledge and the current challenges concerning the biomolecule coronas and, in general, the 2D nano-biointerface established when peptides and proteins interact with the nanosheet surface. Specifically, this review includes both experimental and simulation studies, including some recent machine learning results of a wide range of nanomaterial and peptide/protein systems
On the methods of evaluation of the apparent resistivity under conditions of low message-to-noise ratio
No full text
On the methods of evaluation of the apparent resistivity under conditions of low message-to-noise ratio
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Angiogenin and copper crossing in wound healing
Full text linkAngiogenesis plays a key role in the wound healing process, involving the migration, growth, and differentiation of endothelial cells. Angiogenesis is controlled by a strict balance of different factors, and among these, the angiogenin protein plays a relevant role. Angiogenin is a secreted protein member of the ribonuclease superfamily that is taken up by cells and translocated to the nucleus when the process of blood vessel formation has to be promoted. However, the chemical signaling that activates the protein, normally present in the plasma, and the transport pathways through which the protein enters the cell are still largely unclear. Copper is also an angiogenic factor that regulates angiogenin expression and participates in the activation of common signaling pathways. The interaction between angiogenin and copper could be a relevant mechanism in regulating the formation of new blood vessel pathways and paving the way to the development of new drugs for chronic non-healing wounds
The influence of fluorescent silica nanoparticle surface chemistry on the energy transfer processes with lipid bilayers
No full textMultifunctional nanoparticles (NPs) are an advantageous scaffold for assembling hybrid bio-inorganic nanoplatforms, with impact on key technologies, including molecular diagnostics, therapeutics, bioengineering, biocatalysis, energy generation and storage. In the present work we used core-shell silica NPs, coumarin-doped in the core and surface-tailored with different chemical moieties (-PEG, -COOH, -NH2), as a possible nanocarrier for drug delivery and imaging. The nanoparticle surface was further decorated with lipid bilayers by the interaction with fluorescent small unilamellar lipid vesicles bearing different charges, namely zwitterionic (PC), anionic (PS25) and cationic (EPC25). The fluorescence energy transfer (FRET) processes between the silica nanoparticles and the lipid bilayers, dye-labelled with nitrobenzoxadiazole and/or rhodamine fluorescent moieties, were investigated to exploit the behaviour of the hybrid biomembrane-NP assembly as a theranostic nanocarrier. A relevant role of electrostatic interactions to influence the photophysical properties of the hybrid lipid-NP systems resulted. In proof-of-concept cellular experiments, an increased cellular internalization of NP-PEG/PS25 and NP-NH2/PS25 compared to the respective bare nanoparticles was observed, as well as a decreased cellular uptake, both in the nuclei and in the cytoplasm, in both NP-PEG/EPC25 and NP-COOH/EPC25 systems with respect to the cationic lipids alone. Moreover, intracellular FRET processes were detected by in vitro cell imaging with confocal microscopy, emphasizing the potentialities of such nanoplatforms in theranostic applications
Enhanced plasmonic processes in amino-rich plasma polymer films for applications at the biointerface
No full textA new plasmonic biosensor was developed in a planar chip-based format by coupling the plasmonic properties of gold nanoparticles (Au NPs) with the mechanical and bioadhesive features of unconventional organic thin films deposited from plasma, namely primary amine-based plasma polymer films (PPFs). A self-assembled layer of spherical Au NPs, 12 nm in diameter, was electrostatically immobilized onto optically transparent silanised glass. In the next step, the Au NP layer was coated with an 18 nm polymeric thick PPF layerviathe simultaneous polymerization/deposition of a cyclopropylamine (CPA) precursor performed by radio frequency discharge, both in pulsed and in continuous wave modes. The CPA PFF surface plays the dual role of an adsorbent towards negatively charged chemical species as well as an enhancer of plasmonic signals. The biosensor was tested in a proof-of-concept series of experiments of human serum albumin physisorption, and chosen as a model system for blood serum. The peculiar surface features of CPA PPF, before and after the exposure to buffered solution of fluorescein isothiocyanate-labelled human serum albumin (FITC-HSA), were investigated by a multi-technique approach, including UV-visible and X-ray photoelectron spectroscopies, atomic force microscopy, scanning electron microscopy, contact angle and surface free energy measurements. The results showed the very promising potentialities from both bioanalytical and physicochemical points of view in scrutinizing the macromolecule behavior at the biointerface
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