An Updated Review: Opuntia ficus indica (OFI) Chemistry and Its Diverse Applications

The beneficial nutrients and biologically active ingredients extracted from plants have received great attention in the prevention and treatment of several diseases, including hypercholesterolemic, cancer, diabetes, cardiovascular disorders, hypoglycemic, hypolipidemic, edema, joint pain, weight control, eye vision problems, neuroprotective effects, and asthma. Highly active ingredients predominantly exist in fruit and cladodes, known as phytochemicals (rich contents of minerals, betalains, carbohydrates, vitamins, antioxidants, polyphenols, and taurine), which are renowned for their beneficial properties in relation to human health. Polyphenols are widely present in plants and have demonstrated pharmacological ability through their antimicrobial, anti-inflammatory, anti-bacterial, and antioxidant capacity, and the multi-role act of Opuntia ficus indica makes it suitable for current and future usage in cosmetics for moisturizing, skin improvement, and wound care, as healthful food for essential amino acids, as macro and micro elements for body growth, in building materials as an eco-friendly and sustainable material, as a bio-composite, and as an insulator. However, a more comprehensive understanding and extensive research on the diverse array of phytochemical properties of cactus pear are needed. This review therefore aims to gather and discuss the existing literature on the chemical composition and potential applications of cactus pear extracts, as well as highlight promising directions for future research on this valuable plant

Novel homogeneous selective electrocatalysts for CO2 reduction: an electrochemical and computational study of cyclopentadienyl-phenylendiamino-cobalt complexes

Four cyclopentadienyl-phenylendiamino-cobalt complexes [CoCp(bqdi)] with different substituents (R) at the phenylene moiety (bqdi, I; o-perfluoro-bqdi, II; p-NO2-bqdi, III; p-COOH-bqdi, IV) have been studied with an aim to investigate their capability as catalysts for the CO2 reduction. These compounds were characterized by cyclic voltammetry measurements both under nitrogen and CO2 atmospheres, showing an increase in the cathodic current ranging from 3.36 (III) to 5.59 times (II) that of the measurement under nitrogen. Moreover, with the addition of water, the current enhancement in the presence of CO2 reaches 31.07 times that of the case of complex II. Interestingly, these complexes exhibit very good selectivity toward CO2 reduction irrespective of hydrogen even in the presence of water. The relative turnover frequencies were also estimated, given the values ranging from 3.23 (III) to 187.21 s−1 (II) in the presence of water. In addition, these results were analysed by means of density functional theory (DFT) calculations and Fukui functions analysis. In particular, DFT results clearly show effects of different substituents on the electrochemical properties of these compounds. Whereas, the Fukui functions analysis indicates that the most favourable positions for an electrophilic attack on the reduced complex are the nitrogen and cobalt atoms

Sulphur vs NH Group: Effects on the CO2 Electroreduction Capability of Phenylenediamine-Cp Cobalt Complexes

The cobalt complex (I) with cyclopentadienyl and 2-aminothiophenolate ligands was investigated as a homogeneous catalyst for electrochemical CO2 reduction. By comparing its behavior with an analogous complex with the phenylenediamine (II), the effect of sulfur atom as a substituent has been evaluated. As a result, a positive shift of the reduction potential and the reversibility of the corresponding redox process have been observed, also suggesting a higher stability of the compound with sulfur. Under anhydrous conditions, complex I showed a higher current enhancement in the presence of CO2 (9.41) in comparison with II (4.12). Moreover, the presence of only one -NH group in I explained the difference in the observed increases on the catalytic activity toward CO2 due to the presence of water, with current enhancements of 22.73 and 24.40 for I and II, respectively. DFT calculations confirmed the effect of sulfur on the lowering of the energy of the frontier orbitals of I, highlighted by electrochemical measurements. Furthermore, the condensed Fukui function f - values agreed very well with the current enhancement observed in the absence of water

Fluorination induced electronic effects on Pt(II) square-planar complex of o-phenylenediimine ligand

A novel complex [Pt(C6F4(NH)2)2] (2), formed by a Pt(ii) cation bound to two molecules of the tetrafluorinated 1,2-phenylenediimine ligand, has been synthesized and characterized by electrochemical and XRD measurements, UV-vis-NIR spectroscopy as well as by DFT and TD-DFT calculations. The effect induced by the fluorine atoms has been highlighted by comparison with the corresponding Ni (1H) and Pt (2H) hydrogenated complexes. The cyclic voltammetry data show that the reduction and the oxidation processes of 2 are easier and more difficult (by about 0.5 V), respectively, compared to those of 1H and 2H, suggesting that the electron withdrawing ability of the fluorine atoms lowers the energy level of both the HOMO and the LUMO. UV-vis-NIR measurements are similar for all the three complexes, indicating similar HOMO-LUMO gaps and that the effects of fluorination on the frontier orbitals are roughly the same. Moreover, polymorphism in the powder form of 2 has been highlighted by XRD measurements while the film presents only one phase. Furthermore, this complex shows a field-effect for n-type carriers. All the experimental results are also supported by the calculations, which show the role played by the fluorine atoms in the electronic structure of 2

Le Iniziative di biblioteca digitale negli atenei italiani

This is the presentation of a survey about the initiatives of digital libraries in Italian universities. Conducted with the help of a monitoring form for coordinators and presidents of university libraries systems, the survey had the aim of collecting data and information about the initiatives promoted by universities in order to foster sharing and discussion of ongoing experiences and projects that are being started. The analysis of its results (done considering categories such as the involved subjects, times, costs, funding channels, technologies, ways of usage, etc.) according to the two authors highlighted the necessity of defining a common trend line for the Italian academic digital library, through which it's possible to achieve forms of coordination between existing initiatives, the adoption of international standards, the integration of technological tools, the use of non academic fund programmes

A New Shear-Velocity Model of Continental Australia Based on Multi-Scale Surface-Wave Tomography

The Australian Seismological Reference Model (AuSREM) represents a state-of-the-art geophysical synthesis of the Australian continent. To date, its shear-wave component has limited resolution at lower-crustal to uppermost-mantle depths, where it is mainly constrained by sparse measurements collected at the local scale. In this study, we compile a large data set of surface-wave phase velocities based on seismic ambient noise and teleseismic earthquakes, to produce Rayleigh and Love phase-velocity maps of continental Australia in a broad period range (4–200 s). Via transdimensional Bayesian inversion, we translate the phase-velocity maps into a 3-D shear-wave velocity model extending to 300 km depth. Owing to the unprecedented seismic coverage and to the joint use of ambient-noise and teleseismic data, the retrieved model fills a tomographic gap in the known shear-wave velocity structure of the continent, comprising lower-crustal to uppermost mantle depths. Consistent with AuSREM, strong velocity heterogeneities in our model highlight the (faster) cratonic blocks and the (slower) sedimentary basins at upper-crustal depths. At mantle depths, the most prominent feature of the continent is a large-scale eastward decrease in shear-wave velocity. We interpret our observations in light of the relevant literature, and produce depth maps of the Moho and lithosphere-asthenosphere boundary (LAB). Notably, our LAB proxy features a stripe of thicker lithosphere extending to the east coast, which is not visible in the AuSREM LAB model. This observation supports the idea that lateral variations in lithospheric thickness control both the composition and volume of surface volcanism in eastern Australia

Substitution Effects on the Optoelectronic Properties of Coumarin Derivatives

Coumarin derivatives have gathered major attention largely due to their versatile utility in a wide range of applications. In this framework, we report a comparative computational investigation on the optoelectronic properties of 3-phenylcoumarin and 3-heteroarylcoumarin derivatives established as enzyme inhibitors. Specifically, we concentrate on the variation in the optoelectronic characteristics for the hydroxyl group substitutions within the coumarin moiety. In order to realize our aims, all-electron density functional theory and time dependent density functional theory calculations were performed with a localized Gaussian basis-set matched with a hybrid exchange–correlation functionals. Molecular properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, vertical ionization (IEV) and electron affinity energies, absorption spectra, quasi-particle gap, and exciton binding energy values are examined. Furthermore, the influence of solvent on the optical properties of the molecules is considered. We found a good agreement between the experimental (8.72 eV) and calculated (8.71 eV) IEV energy values for coumarin. The computed exciton binding energy of the investigated molecules indicated their potential optoelectronics application

Rheology of Conductive High Reactivity Carbonaceous Material (HRCM)-Based Ink Suspensions: Dependence on Concentration and Temperature

The present case study reports a shear rheological characterization in the temperature domain of inks and pastes loaded with conductive High Reactivity Carbonaceous Material (HRCM) consisting mainly of few-layers graphene sheets. The combined effect of filler concentration and applied shear rate is investigated in terms of the shear viscosity response as a function of testing temperature. The non-Newtonian features of shear flow ramps at constant temperature are reported to depend on both the HRCM load and the testing temperature. Moreover, temperature ramps at a constant shear rate reveal a different viscosity-temperature dependence from what is observed in shear flow ramps while maintaining the same filler concentration. An apparent departure from the well-known Vogel-Fulcher-Tamman relationship as a function of the applied shear rate is also reported

Near-IR Absorbers Based on Pt(II)-Dithiolene Donor–Acceptor Charge-Transfer (CT) Systems: A Structural Analysis to Highlight DA Interactions

The packing interactions of a series of electron donor (D) and electron acceptor (A) charge transfer (CT) near-IR absorbers based on platinum-dithiolene complexes are reinvestigated here as a case study also by using the Hirshfeld surface analysis. This analysis on systems, which exhibit the 1:1, 2:1 and 2:2 columnar stacking patterns between D and A, allows to point out that several inter-actions of atoms and fragments are involved in the stacking interactions but also that only a lim-ited fraction of these interactions, limited to the 1:1 D/A columnar stacking case, can be relatable to the absorption features of this class of compounds