182 research outputs found

    Inheritance Law and Investment in Family Firms

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    Entrepreneurs may be legally bound to bequeath a minimal stake to non-controlling heirs. The size of this stake can reduce investment in family firms, by reducing the future income they can pledge to external financiers. Using a purpose-built indicator of the permissiveness of inheritance law and data for 10,004 firms from 38 countries in 1990-2006, we find that stricter inheritance law is associated with lower investment in family firms, but does not affect investment in non-family firms. Moreover, as the model predicts, inheritance law affects investment only in family firms that experience a succession

    AIEgen orthopalladated hybrid polymers for efficient inactivation of the total coliforms in urban wastewater

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    Monitorable AIE polymers with a bioactive pattern are employed in advanced biomedical applications such as functional coatings, theranostic probes, and implants. After the global COVID-19 pandemic, interest in developing surfaces with superior antimicrobial, antiproliferative, and antiviral activities dramatically increased. Many formulations for biocide surfaces are based on hybrid organic/inorganic materials. Palladium (II) complexes display relevant activity against common bacteria, even higher when compared to their uncoordinated ligands. This article reports the design and synthesis of two series of orthopalladated polymers obtained by grafting a cyclopalladated fragment on two diferent O, N chelating Schif base polymers. Diferent grafting percentages were examined and compared for each organic polymer. The fuorescence emission in the solid state was explored on organic matrixes and grafted polymers. DFT analysis provided a rationale for the role of the coordination core. The antibacterial response of the two series of hybrid polymers was tested against the total coliform group of untreated urban wastewater, revealing excellent inactivation abilit

    A novel l-shaped fluorescent probe for aie sensing of zinc (Ii) ion by a dr/nir response

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    In the field of optical sensors, small molecules responsive to metal cations are of current interest. Probes displaying aggregation-induced emission (AIE) can solve the problems due to the aggregation-caused quenching (ACQ) molecules, scarcely emissive as aggregates in aqueous media and in tissues. The addition of a metal cation to an AIE ligand dissolved in solution can cause a “turn-on” of the fluorescence emission. Half-cruciform-shaped molecules can be a winning strategy to build specific AIE probes. Herein, we report the synthesis and characterization of a novel L-shaped fluorophore containing a benzofuran core condensed with 3-hydroxy-2-naphthaldehyde crossed with a nitrobenzene moiety. The novel AIE probe produces a fast colorimetric and fluorescence response toward zinc (II) in both in neutral and basic conditions. Acting as a tridentate ligand, it produces a complex with enhanced and red-shifted emission in the DR/NIR spectral range. The AIE nature of both compounds was examined on the basis of X-ray crystallography and DFT analysis

    Vibrational analysis of paraelectric–ferroelectric transition of linbo3: An ab-initio quantum mechanical treatment

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    The phase transitions between paraelectric (PE) and ferroelectric (FE) isomorph phases of LiNbO3 have been investigated quantum mechanically by using a Gaussian-type basis set, the B3LYP hybrid functional and the CRYSTAL17 code. The structural, electronic and vibrational properties of the two phases are analyzed. The vibrational frequencies evaluated at the Γ point indicate that the paraelectric phase is unstable, with a complex saddle point with four negative eigenvalues. The energy scan of the A2u mode at −215 cm−1 (i215) shows a dumbbell potential with two symmetric minima. The isotopic substitution, performed on the Li and Nb atoms, allows interpretation of the nontrivial mechanism of the phase transition. The ferroelectric phase is more stable than the paraelectric one by 0.32 eV

    Thermo-Induced Fluorochromism in Two AIE Zinc Complexes: A Deep Insight into the Structure-Property Relationship

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    Solid-state emitters exhibiting mechano-fluorochromic or thermo-fluorochromic responses represent the foundation of smart tools for novel technological applications. Among fluo-rochromic (FC) materials, solid-state emissive coordination complexes offer a variety of fluorescence responses related to the dynamic of noncovalent metal-ligand coordination bonds. Relevant FC behaviour can result from the targeted choice of metal cation and ligands. Herein, we report the synthesis and characterization of two different colour emitters consisting of zinc complexes obtained from N,O bidentate ligands with different electron-withdrawing substituents. The two complexes are blue and orange solid-state fluorophores, respectively, highly responsive to thermal and me-chanical stress. These emitters show a very different photoluminescent (PL) pattern as recorded before and after the annealing treatment. Through X-ray structural analysis combined with thermal analysis, infrared (IR) spectroscopy, PL, and DFT simulation we provide a comprehensive analysis of the structural feature involved in the fluorochromic response. Notably, we were able to correlate the on-off thermo-fluorochromism of the complexes with the structural rearrangement at the zinc coordination core

    Benzodifuran-based fluorescent brighteners: A novel platform for plant cell wall imaging

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    Herein we designed three novel fluorescent brightening agents based on a benzodifuran skeleton. The compounds are colorless fluorophores emitting in the blue region with an improved water solubility and ability to interact with living cells. A complete understanding of the emission mechanisms was achieved by Density Functional Theory study based on X-ray crystallographic analysis. The fluorescence quantum yields were measured in different solvents and at different pH values. The ability of the different fluorophores to stain cell compartments of plant root samples was tested in water- and glycerol-based solutions. Through fluorescence microscopy technique two probes with a different functionalized branching chain proved to be efficient stains for plant root cell wall. The cationic probe has no harmful effect on plant tissues and is suitable for in vivo fluorescent visualization of plant root cell boundaries. This study sheds light on the potential use of brighteners containing a central benzodifuran core as tools for imaging of fixed and alive plant tissues

    Spatial variability of nitrogen dioxide and formaldehydeand residential exposure of children in the industrial area of Viadana, Northern Italy

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    Chipboard production is a source of ambient air pollution. We assessed the spatial variability of outdoor pollutants and residentialexposure of children living in proximity to the largest chipboard industry in Italy and evaluated the reliability of exposureestimates obtained from a number of available models. We obtained passive sampling data on NO2and formaldehyde collectedby the Environmental Protection Agency of Lombardy region at 25 sites in the municipality of Viadana during 10 weeks (2017-2018) and compared NO2measurements with average weekly concentrations from continuous monitors. We compared interpo-lated NO2and formaldehyde surfaces with previous maps for 2010. We assessed the relationship between residential proximity tothe industry and pollutant exposures assigned using these maps, as well as other available countrywide/continental models basedon routine data on NO2, PM10, andPM2.5. The correlation between NO2concentrations from continuous and passive samplingwas high (Pearson'sr= 0.89), although passive sampling underestimated NO2especially during winter. For both 2010 and 2017-2018, we observed higher NO2and formaldehyde concentrations in the south of Viadana, with hot-spots in proximity to theindustry. PM10and PM2.5exposures were higher for children at 3.5 km to theindustry, whereas NO2exposure was higher at 1-1.7 km to the industry. Road and population densities were also higher close tothe industry. Findings from a variety of exposure models suggest that children living in proximity to the chipboard industry inViadana are more exposed to air pollution and that exposure gradients are relatively stable over time

    Effect of indoor nitrogen dioxide on lung function in urban environment

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    Background: High levels of indoor NO2 are associated with increased asthma symptoms and decreased expiratory peak flows in children. We investigated the association of exposure to domestic indoor NO2, objectively measured in winter and spring, with respiratory symptoms and lung function in a sample of adolescents from a southern Mediterranean area. Methods: From a large school population sample (n=2150) participating in an epidemiological survey in the urban area of the City of Palermo (southern Italy), a sub-sample of 303 adolescents was selected which furnished an enriched sample for cases of current asthma. All subjects were evaluated by a health questionnaire, skin prick tests and spirometry. One-week indoor NO2 monitoring of their homes was performed by diffusive sampling during spring and again during winter. Results: We found that about 25% of subjects were exposed to indoor NO2 levels higher than the 40μg/m3 World Health Organization limit, during both spring and winter. Moreover, subjects exposed to the highest indoor NO2 concentrations had increased frequency of current asthma (p=0.005), wheeze episodes in the last 12 months (p<0.001), chronic phlegm (p=0.013), and rhinoconjunctivitis (p=0.008). Finally, subjects with a personal history of wheeze ever had poorer respiratory function (FEF25-75%, p=0.01) when exposed to higher indoor NO2 concentrations. Conclusions: Home exposure to high indoor NO2 levels frequently occurs in adolescents living in a southern Mediterranean urban area and is significantly associated with the risks for increased frequency of both respiratory symptoms and reduced lung function
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