Ferula L. Plant Extracts and Dose-Dependent Activity of Natural Sesquiterpene Ferutinin: From Antioxidant Potential to Cytotoxic Effects

The employment studies of natural extracts in the prevention and treatment of several diseases highlighted the role of different species of genus Ferula L., belonging to the Apiaceae family, dicotyledonous plants present in many temperate zones of our planet. Ferula communis L. is the main source of sesquiterpene ferutinin, a bioactive compound studied both in vitro and in vivo, because of different effects, such as phytoestrogenic, antioxidant, anti-inflammatory, but also antiproliferative and cytotoxic activity, performed in a dose-dependent and cell-dependent way. The present review will focus on the molecular mechanisms involved in the different activities of Ferutinin, starting from its antioxidant potential at low doses until its ionophoric property and the subsequent mitochondrial dysfunction induced through administration of high doses, which represent the key point of its anticancer action. Furthermore, we will summarize the data acquired from some experimental studies on different cell types and on several diseases. The results obtained showed an important antioxidant and phytoestrogenic regulation with lack of typical side effects related to estrogenic therapy. The preferential cell death induction for tumor cell lines suggests that ferutinin may have anti-neoplastic properties, and may be used as an antiproliferative and cytotoxic agent in an estrogen dependent and independent manner. Nevertheless, more data are needed to clearly understand the effect of ferutinin in animals before using it as a phytoestrogen or anticancer drug.     

Superbase promoted synthesis of dienamides as useful intermediates for the synthesis of α-ketoamides, γ-lactams and cyclic imino ethers

Alkoxydienamides 2 have been synthesized exploiting the reactivity of α,β-unsaturated acetals 1 with isocyanates in the presence of Schlosser's superbase LIC-KOR. In a mild acidic medium, 2 can then be promptly converted both into α-ketoamides 3 and into substituted 2-pyrrolidinones 4 or imino ethers 5 by choosing the appropriate experimental conditions.     

Particle tracer response across shocks measured by PIV

The experimental approach used for the evaluation of the particle response time across a stationary shock wave is assessed by means of PIV measurements. The study focuses on the experimental requirements for a reliable and unbiased measurement of the particle response time τ _p and length ξ _p based on a single-exponent decaying law. A numerical simulation of the particle response experiment returns the parameters governing the measurement: namely the normalized spatial and temporal resolution, shock strength, and digital resolution. Representing the velocity decay in logarithmic coordinates it is shown that measurements performed with laser pulse separation time up to τ _p and interrogation window up to ξ _p still yield unbiased results for the particle response. A set of experiments on the particle response across a planar oblique shock wave was conducted to verify the results from the numerical assessment. Liquid droplets of DEHS and solid tracer particles of silicon and titanium dioxide with different primary crystal size are compared. The resulting temporal response ranges from 2 to 3 μs, corresponding to values commonly reported in literature, to almost 0.3 μs when particles are properly dehydrated and a filter is applied before injection into the wind tunnel. It is the first experimental evidence of particle tracers with a measured response time lower than 0.4 μs. The same procedure is applied to attempt the measurement of individual particle tracers by particle tracking velocimetry to estimate the spread in the distribution of tracer time response. The latter analysis is limited by the particle image tracking precision error, which biases the results introducing a wider broadening of the particle velocity distribution.     

The aero-acoustic resonance behavior of partially covered slender cavities

The present investigation focuses on the aero-acoustic resonance of cavities with a width much larger than their length or depth and partially covered, as often encountered in automotive door gaps. The cavities are under influence of a low Mach number flow with a relatively thick boundary layer. Under certain conditions, these cavities can acoustically resonate with the flow. The upstream and downstream edge of the opening as well as the cover lip overhang location and boundary layer thickness are parametrically varied in an experimental campaign, and the effect of the parameters on the resonance amplitude is investigated. Slender rectangular cavity geometries with an opening length of 8 mm and spanwise width of 500 mm are used. The cavity flow-induced acoustic response is measured with pressure transducers at different spanwise locations inside the cavity. Hot-wire measurements are performed to quantify the boundary layer characteristics. Furthermore, high-speed time-resolved particle image velocimetry is used to capture the instantaneous velocity field around the opening geometries. When the boundary layer thickness is increased, the cavity resonance amplitude diminishes. The cover lip overhang location has a large influence on the resonance response, which can be attributed to changes in the cavity driven flow properties. Rounding of the upstream edge promotes resonance, whereas rounding of the downstream edge can diminish it. A possible explanation of the phenomenon is given on the basis of the PIV observations.     

Electrocatalytic Performances of Pure and Mixed Hexacyanoferrates of Cu and Pd for the Reduction of Hydrogen Peroxide

A study on the performances of mixed hexacyanoferrates of Cu and Pd (CuPdHCFs), potentiodynamically grown on glassy carbon surfaces, was carried out. Morphological (SEM‐EDX analysis) and electrochemical characterizations were performed, and the electrocatalytic ability of films with various compositions was tested by chronoamperometry. CuPdHCFs were found to display good electrocatalytic performances, with a maximum sensitivity of 45.3 mA M^?1 cm^?2 at 0.0 V vs. SCE (depending on the Cu and Pd ratio), against the value of 9.1 mA M^?1 cm^?2 obtained with pure copper hexacyanoferrate (CuHCF). Additionally, mixed hexacyanoferrates showed a higher pH and operational stability. The key role of Cu in Cu‐based hexacyanoferrates was investigated and highlighted.     

Surface Plasmon Resonance imaging-based sensing for anti-bovine immunoglobulins detection in human milk and serum

Only few papers deal with Surface Plasmon Resonance imaging (SPRi) direct detection on complex matrices, limiting the biosensor application to real analytical problems. In this work a SPRi biosensor for anti-bovine IgG detection in untreated human bodily fluids, i.e. diluted human serum and milk, was developed. Enhanced levels of cow's milk antibodies in children's serum are suspected for their possible correlation with Type 1 diabetes during childhood and their detection in real samples was up to now performed by classical immunoassays based on indirect detection. The biosensor was optimised in standard samples and then in untreated human milk for anti-bovine IgG direct detection. The key novelty of the work is the evaluation of matrix effect by applying to real samples an experimental and ex ante method previously developed for SPRi signal sampling in standard solutions, called "Data Analyzer"; it punctually visualises and analyses the behaviour of receptor spots of the array, to select only spot areas with the best specific vs. unspecific signal values. In this way, benefits provide by SPRi image analysis are exploited here to quantify and minimise drawbacks due to the matrix effect, allowing to by-pass every matrix pre-treatment except dilution.     

Application of PIV in a Mach 7 double-ramp flow

The flow over a two-dimensional double compression ramp configuration is investigated by means of schlieren visualization, quantitative infrared thermography and particle image velocimetry (PIV) in a short-duration facility producing a free-stream flow at Mach 7. The study focuses upon the accuracy assessment of PIV in the hypersonic flow regime including flow facility effects such as repeatability of test conditions. The solid tracer particles are characterized by means of electron microscopy as well as by measuring the dynamic response across a planar oblique shock wave with PIV. The experiments display a strong variation in the light scattering intensity of the seeded flow over the flow field, due to the large flow compressibility. The mean velocity spatial distribution allows to clearly identify the shock pattern and the main features of the flow downstream of the shocks. However, the spatial resolution is insufficient to determine the wall flow properties. Furthermore the velocity data obtained with the PIV technique allow the determination of the spatial distribution of the Mach number under the hypothesis of adiabatic flow. The double ramp configuration with a variable second compression angle exhibits shock–shock interactions of Edney type VI or V for the lowest and highest ramp angle, respectively. A single heat transfer peak is detected with infrared thermography on the second ramp in case of a type VI interaction while for the type V shock interaction a double heat transfer peak is found. Shock wave angles measured with PIV are in good agreement with theory and the overall flow topology is consistent with schlieren visualization. Also in this respect the results are in agreement with compressible flow theory.     

Tomographic particle image velocimetry

This paper describes the principles of a novel 3D PIV system based on the illumination, recording and reconstruction of tracer particles within a 3D measurement volume. The technique makes use of several simultaneous views of the illuminated particles and their 3D reconstruction as a light intensity distribution by means of optical tomography. The technique is therefore referred to as tomographic particle image velocimetry (tomographic-PIV). The reconstruction is performed with the MART algorithm, yielding a 3D array of light intensity discretized over voxels. The reconstructed tomogram pair is then analyzed by means of 3D cross-correlation with an iterative multigrid volume deformation technique, returning the three-component velocity vector distribution over the measurement volume. The principles and details of the tomographic algorithm are discussed and a parametric study is carried out by means of a computer-simulated tomographic-PIV procedure. The study focuses on the accuracy of the light intensity field reconstruction process. The simulation also identifies the most important parameters governing the experimental method and the tomographic algorithm parameters, showing their effect on the reconstruction accuracy. A computer simulated experiment of a 3D particle motion field describing a vortex ring demonstrates the capability and potential of the proposed system with four cameras. The capability of the technique in real experimental conditions is assessed with the measurement of the turbulent flow in the near wake of a circular cylinder at Reynolds 2,700.