Search results for "scienza"

A poly-L-lactic acid/ collagen/glycosaminoglycan matrix for tissue engineering applications

2017

Adhesion of tissue cells to biomaterials is a prerequisite of paramount importance for the effectiveness of a tissue engineering construct (cell and scaffolds). Functionalization of polymeric scaffolds with organic polymers, such as collagen or proteoglycans, is a promising approach in order to improve the cytocompatibility. As a matter of fact, organic polymers, isolated directly from the extracellular matrix, contain a multitude of surface ligand (fibronectin, laminin, vitronectin) and arginine–glycine–aspartic acid-containing peptides that promote cell adhesion. In tissue engineering, the combination of organic and synthetic polymers gives rise to scaffolds characterized simultaneously …

Plasma modified PLA electrospun membranes for actinorhodin production intensification in Streptomyces coelicolor immobilized-cell cultivations

2017

Most of industrially relevant bioproducts are produced by submerged cultivations of actinomycetes. The immobilization of these Gram-positive filamentous bacteria on suitable porous supports may prevent mycelial cell-cell aggregation and pellet formation which usually negatively affect actinomycete submerged cultivations, thus, resulting in an improved biosynthetic capability. In this work, electrospun polylactic acid (PLA) membranes, subjected or not to O2-plasma treatment (PLA-plasma), were used as support for immobilized-cell submerged cultivations of Streptomyces coelicolor M145. This strain produces different bioactive compounds, including the blue-pigmented actinorhodin (ACT) and red-p…

Fractional hereditariness of lipid membranes: Instabilities and linearized evolution

2016

In this work lipid ordering phase changes arising in planar membrane bilayers is investigated both accounting for elas- ticity alone and for effective viscoelastic response of such assemblies. The mechanical response of such membranes is studied by minimizing the Gibbs free energy which penalizes perturbations of the changes of areal stretch and their gradients only [1]. As material instabilities arise whenever areal stretches characterizing homogeneous configurations lie inside the spinoidal zone of the free energy density, bifurcations from such configurations are shown to occur as oscillatory perturbations of the in-plane displacement. Experimental observations [2] show a power-law in-pl…

Synthesis and antiproliferative mechanism of action of pyrrolo[3′,2′:6,7] cyclohepta[1,2-d]pyrimidin-2-amines as singlet oxygen photosensitizers

2016

A new series of pyrrolo[3′,2′:6,7]cyclohepta[1,2-d]pyrimidin-2-amines, was conveniently prepared using a versatile and high yielding multistep sequence. A good number of derivatives was obtained and the cellular photocytotoxicity was evaluated in vitro against three different human tumor cell lines with EC50 (0.08–4.96 μM) values reaching the nanomolar level. Selected compounds were investigated by laser flash photolysis. The most photocytotoxic derivative, exhibiting a fairly long-lived triplet state (τ ∼ 7 μs) and absorbance in the UV–Vis, was tested in the photo-oxidations of 9,10-anthracenedipropionic acid (ADPA) by singlet oxygen. The photosentizing properties are responsible for the c…

Green Composites Based on PLA and Agricultural or Marine Waste Prepared by FDM

2021

Three dimensional-printability of green composites is recently growing in importance and interest, especially in the view of feasibility to valorize agricultural and marine waste to attain green fillers capable of reducing bioplastic costs, without compromising their processability and performance from an environmental and mechanical standpoint. In this work, two lignocellulosic fillers, obtained from Opuntia ficus indica and Posidonia oceanica, were added to PLA and processed by FDM. Among the 3D printed biocomposites investigated, slight differences could be found in terms of PLA molecular weight and filler aspect ratio. It was shown that it is possible to replace up to 20% of bioplastic …

Il sorriso del giovane Fermi

2012

Synthesis, Structural Analysis, Fiber Formation and Preliminary Anticancer Characterization of the Organotin Polyether from Dibutyltin Dichloride and…

2012

The organotin polyether derived from reaction of dibutyltin dichloride and 2,5-dimethyl-3-hexyne-2,5-diol was rapidly synthesized employing classical interfacial polymerization in 65% yield and a chain length of 360 units. IR results are consistent with the polyether structure. Bands characteristic of the formation of the Sn-O are present and bands characteristic of the Sn-Cl are absent. F MALDI MS results in the low mass range gives ion fragment clusters to five units. Isotopic abundance matches for tin are consistent with its presence in these ion fragment clusters. In the high mass range ion fragment clusters to greater than 300 units are found. The products offer outstanding inhibition …

The effects of water absorption and salt fog exposure on agglomerated cork compressive response

2022

The replacement of synthetic foams with agglomerated cork in sandwich composites can meet the increasing environmental concerns. Its peculiar morphology and chemical composition lead to outstanding dimensional recovery that endorsed a broad investigation of its compressive behavior. The knowledge of neat material response is fundamental to obtain a reliable design dataset, but it is necessary to consider all the environmental factors (water, moisture and sunlight) that significantly modify material mechanical properties. In view of this, the present work investigates the effect of distilled and seawater absorption and salt fog exposure on the compressive behavior of two agglomerated corks w…

Global-Local model for guided wave scattering problems with application to defect characterization in built-up composite structures

2020

Abstract Predicting scattering of elastic guided waves in multi-layered solid plates with geometrical and/or material discontinuities is of great interest to many fields, including ultrasonic-based Non-Destructive Testing (NDT) and health monitoring of critical structural components (SHM). The problem is complicated by the multimode and dispersive behaviour of the guided waves. This paper describes a unified Global-Local (GL) approach that is computationally efficient in cases that can be very complex in terms of geometry and/or material properties. One example of this is a composite built-up structure. The proposed GL procedure discretizes the “local” region with the scattering discontinui…

Predictive factors of overall functioning improvement in patients with chronic schizophrenia and schizoaffective disorder treated with paliperidone p…

2018

BACKGROUND Long-acting injectable (LAI) antipsychotics can improve medication adherence and reduce hospitalisation rates compared with oral treatments. Paliperidone palmitate (PAL) and aripiprazole monohydrate (ARI) LAI treatments were associated with improvements in global functioning in patients with schizophrenia. OBJECTIVE The objective of this study was to assess the predictive factors of better overall functioning in patients with chronic schizophrenia and schizoaffective disorder treated with PAL and ARI. METHOD Enrolled were 143 (97 males, 46 females, mean age 38.24 years, SD = 12.65) patients with a diagnosis of schizophrenia or schizoaffective disorder, whom we allocated in two gr…