581 research outputs found

    Iodine biofortification of sweet basil and lettuce grown in two hydroponic systems

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    Two hydroponic techniques (floating system and aeroponics) were assessed for iodine (I) biofortification of sweet basil (Ocimum basilicum L.) and baby-leaf lettuce (Lactuca sativa L.). Iodine was supplemented by adding KI into the nutrient solution to achieve a final I concentration of 10 μM. Shoot biomass production and leaf concentration of I, nitrates, total phenols and pigments were measured on the occasion of two successive cuts, 14 and 28 days after transplanting. In both the hydroponic systems, the supplementation of KI represented an effective method for the biofortification of basil as it did not affect the plant growth, while it moderately reduced the biomass production in lettuce. Leaf I accumulation occurred to a greater extent in aeroponics than the floating system in both species. In KI-treated basil plants, leaf I content ranged between 9.76 and 23.58 mg kg− 1 FW. Consequently, 6 g of fresh basil leaves, which is contained in a portion of Italian pesto sauce (12 g), could satisfy 40%–94% of the Recommended Daily Intake (RDI) of iodine for healthy adults (150 μg day− 1). In lettuce, leaf I contents of first-cut leaves were 1.55 and 3.60 mg kg− 1 FW, in the floating system and aeroponics, respectively. Therefore, a serving size of 26 g of lettuce containing I from 1.55 (floating culture) to 3.60 (aeroponics) mg kg− 1 FW could satisfy 27 % to 62 % of the RDI of iodine. Lettuce grew much less in the floating system than aeroponics, probably because of the lower dissolved oxygen level in the nutrient solution as compared to aeroponics. Basil was less sensitive to the oxygen availability in the root zone, since no differences were detected between the two hydroponic systems in terms of fresh and dry biomass

    Copper and Zinc Accumulation in Young Leaves of Eruca sativa (L.) Grown in Soilless Culture

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    Heavy metals are environmental pollutants that cause toxicity in plants and represent a risk for human health, linked to bioaccumulation through the food chain. However, excess accumulation may not occur in young plants in the early stages of exposure to the toxic element. In the present work, rocket (Eruca sativa L.) plants grown in hydroponics were exposed for three weeks to excess concentrations (25, 50, or 100 μM) of Cu or Zn in the nutrient solution and were more sensitive to Cu than Zn toxicity. However, a significant decrease in the leaf biomass production as compared with the control was observed only after two or three weeks, and only minor signals of metal-induced adverse effects were evidenced concerning photosynthesis, oxidative stress indicators, antioxidant metabolites, and macronutrients. After two or three weeks, the leaf level of Cu occasionally approached the upper value associated with the recommended limits of dietary intake for human adults. However, as rocket leaves are commercialized when they achieve a 10–15 cm length, after one week of cultivation in perlite, the plants had an adequate size without metal contamination and could be considered suitable for the food market, even after exposure to Cu or Zn concentrations up to 100 μM

    Direction-dependent secondary bonds and their stepwise melting in a uracil-based molecular crystal studied by infrared spectroscopy and theoretical modeling

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    Three types of supramolecular interactions are identified in the three crystallographic directions in crystals of 1,4-bis[(1-hexylurac-6-yl)ethynyl]benzene, a uracil-based molecule with a linear backbone. These three interactions, characterized by their strongest component, are: intermolecular double H-bonds along the molecular axis, London dispersion interaction of hexyl chains connecting these linear assemblies, and π\pi--π\pi stacking of the aromatic rings perpendicular to the molecular planes. On heating, two transitions happen, disordering of hexyl chains at 473 K, followed by H-bond melting at 534 K. The nature of the bonds and transitions was established by matrix-isolation and temperature-dependent infrared spectroscopy and supported by theoretical computations

    Modelling transpiration of greenhouse gerbera (Gerbera jamesonii H. Bolus) grown in substrate with saline water in a Mediterranean climate

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    Gerbera plants were grown in semi-closed rockwool culture under greenhouse conditions in different seasons in a Mediterranean climate. The plants were irrigated using either fresh (FW; 1.0 mol m−3NaCl)or moderately saline (SW; 9.0 mol m−3NaCl) water. In autumn, NaCl concentration did not influence significantly plant growth, flower production and transpiration (E), which instead were reduced in springin the plants irrigated with SW. In both seasons, water salinity did not affect leaf stomatal resistance (rl),which was determined by the inversion of the Penman–Monteith (PM) equation or measured with a diffusion porometer. The PM formula and two regression equations were calibrated and validated for estimating the hourly rate of daytime transpiration (Ed); a regression model was also fit to nocturnal transpiration (En). Regression models predicted Edas a function of vapour pressure deficit (VPD) and/or the radiation intercepted by the canopy. Leaf area index (LAI), which is required by all the equations, was modelled as function of crop thermal time (i.e. growing degree days). The PM model predicted Ed using a constant value of rl. Model calibration and validation were performed using independent data sets. The irrigation with FW or SW did not require a different calibration of transpiration models. Both PM formula and regression equations provided accurate estimates of Ed; fitted equations explained between 80% and96% of the variance in measured Ed. A linear regression of En against (LAI·VPD) accounted for 92% of measured En

    The response of a small stream in the Lesni potok forested catchment, central Czech Republic, to a short-term in-stream acidification

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    International audienceLesni Potok stream drains a forested headwater catchment in the central Czech Republic. It was artificially acidified with hydrochloric acid (HC1) for four hours to assess the role of stream substrate in acid-neutralisation and recovery. The pH was lowered from 4.7 to 3.2. Desorption of Ca and Mg and desorption or solution of Al dominated acid-neutralisation; Al mobilisation was more important later. The stream substrate released 4,542 meq Ca, 1,184 meq Mg, and 2,329 meq Al over a 45 m long and 1 m wide stream segment; smaller amounts of Be, Cd, Fe, and Mn were released. Adsorption of SO42- and desorption of F? occurred during the acidification phase of the experiment. The exchange reactions were rapidly reversible for Ca, Mg and SO42-; but not symmetric as the substrate resorbed 1083, 790 and 0 meq Ca, Mg, and Al, respectively, in a 4-hour recovery period. Desorption of SO42-; occurred during the resorption of Ca and Mg. These exchange and dissolution reactions delay acidification, diminish the pH depression and retard recovery from episodic acidification. The behaviour of the stream substrate-water interaction resembles that for soil?soil water interactions. A mathematical dynamic mass-balance based model, MASS (Modelling Acidification of Stream pediments), was developed which simulates the adsorption and desorption of base cations during the experiment and was successfully calibrated to the experimental data. Keywords: Al, Ca, Mg, base cations, acid-neutralisation, stream acidification, recovery, stream sediment, experiment, modelling, adsorption, desorption, adsorption, Czech Republic, Lesni Poto

    New lanthanide metalloligands and their use for the assembly of Ln-Ag bimetallic coordination frameworks : stepwise modular synthesis, structural characterization, and optical properties

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    Stepwise self-assembly processes using new lanthanide metalloligands (Ln-MLs) and silver salts have been successfully applied to isolate 4f-4d heterometallic coordination networks of four different structural types. In particular, the new lanthanide tetrakis-chelate complexes NEt4[Ln(L1)4] [HL1 = 1,3-bis(4\u2032-cyanophenyl)-1,3-propanedione; Ln = Eu (1a), La (1b), Nd (1c), Tb (1d)] and NEt4[Ln(L2)4] (HL2 = 1,3-bis(4\u2032-pyridyl)-1,3-propanedione; Ln = Eu (1e), Nd (1f)] have been synthetized, characterized and reacted with different silver salts. The use of NEt4[Ln(L1)4] allowed then to isolate and characterize i) neutral one-dimensional ladder-like species of formula [Ln(L1)4Ag] [Ln = Eu (2a), La(2b), Nd(2c), Tb(2d)] and ii) their supramolecular isomers [Ln(L1)4Ag] [Ln = Eu (3a), La (3b), Nd (3c), Tb (3d)] showing a very unstable 2D network structure, iii) the cationic 2D species [Ln(L1)4Ag2]X [Ln = Eu, X = PF6\u203e, CF3SO3\u203e, ClO4\u203e (4a\u20134c); Ln = Tb, Nd, La X = PF6\u203e (4d\u20134f)] and, only for lanthanum, iv) a fourth 2D species of formula [La(L1)4(H2O)Ag] (5) and sql topology. Of the eight nitrile groups on the MLs potentially coordinating, only a partial number is used for networking with Ag(I), that is, only two in families 2 and 3, and four in family 4 and in network 5. Finally, the four structural types are rationalized in terms of a new \u201cpincer-like\u201d Secondary Building Unit (SBU) consisting of a silver cation coordinating two central carbon atoms (\uf067 carbon) of two different diketonate ligands on the same ML. Therefore, it is shown that compounds 5, 4 and 2\u20133 contain, respectively, none, one or two of such pincer-like SBUs. The luminescence properties of the Ln-MLs and some of their polymeric species have been also investigated in solution and in the solid state

    Medicinal plants and their bacterial microbiota: A review on antimicrobial compounds production for plant and human health

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    Medicinal plants (MPs) have been used since antiquity in traditional and popular medicine, and they represent a very important source of bioactive molecules, including antibiotic, antiviral, and antifungal molecules. Such compounds are often of plant origin, but in some cases, an origin or a modification from plant microbiota has been shown. Actually, the research continues to report the production of bioactive molecules by plants, but the role of plant–endophytic interaction is emerging. Classic examples are mainly concerned with fungal endophytes; however, it has been recently shown that bacterial endophytes can also play an important role in influencing the plant metabolism related to the synthesis of bioactive compounds. In spite of this, a deep investigation on the power of MP bacterial endophytes is lacking. Here, an overview of the studies on MP bacterial microbiota and its role in the production of plant antimicrobial compounds contributing to prime host defense system and representing a huge resource for biotech and therapeutic applications is provided

    Medicinal Plants and Their Bacterial Microbiota: A Review on Antimicrobial Compounds Production for Plant and Human Health

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    Medicinal plants (MPs) have been used since antiquity in traditional and popular medicine, and they represent a very important source of bioactive molecules, including antibiotic, antiviral, and antifungal molecules. Such compounds are often of plant origin, but in some cases, an origin or a modification from plant microbiota has been shown. Actually, the research continues to report the production of bioactive molecules by plants, but the role of plant–endophytic interaction is emerging. Classic examples are mainly concerned with fungal endophytes; however, it has been recently shown that bacterial endophytes can also play an important role in influencing the plant metabolism related to the synthesis of bioactive compounds. In spite of this, a deep investigation on the power of MP bacterial endophytes is lacking. Here, an overview of the studies on MP bacterial microbiota and its role in the production of plant antimicrobial compounds contributing to prime host defense system and representing a huge resource for biotech and therapeutic applications is provided

    Fullerene-driven encapsulation of a luminescent Eu(III) complex in carbon nanotubes

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    A novel CNT-based hybrid luminescent material was obtained via encapsulation of a C60-based Eu(III) complex into single-, double- and multi-walled carbon nanotubes (SWCNTs, DWCNTs and MWCNTs, respectively). Specifically, a luminescent negatively charged Eu(III) complex, electrostatically bonded to an imidazolium-functionalized fullerene cage, was transported inside CNTs by exploiting the affinity of fullerenes for the inner surface of these carbonaceous containers. The filling was performed under supercritical CO2 (scCO2) conditions to facilitate the entrapment of the ion-paired assembly. Accurate elemental, spectroscopic and morphological characterization not only demonstrated the efficiency of the filling strategy, but also the occurrence of nano-ordering of the encapsulated supramolecular luminophores when SWCNTs were employed

    Le Elezioni Politiche 2013

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    Le elezioni politiche del 24 e 25 febbraio 2013 hanno sancito un forte cambiamento della struttura del sistema partitico italiano. In un contesto di altissima volatilità elettorale e di accelerato declino della partecipazione al voto, il sistema è divenuto sostanzialmente tripolare, dopo vent’anni di strutturazione e tenuta del bipolarismo. A questo esito hanno concorso da un lato l’erosione dei principali schieramenti politici che a partire dal novembre 2011 avevano sostenuto l’esperienza del governo Monti (nonché la deludente prova elettorale dello stesso Presidente del Consiglio uscente), e dall’altro lo straordinario successo del Movimento 5 stelle. Quest’ultimo, al primo test elettorale di livello nazionale, ha raccolto un risultato sorprendente, giungendo ad oltre un quarto dei voti validi. Siamo di fronte ad una parentesi momentanea dovuta all’effetto combinato di crisi economica e crisi politica, oppure le contraddizioni interne alla Seconda Repubblica l’hanno condotta effettivamente al suo crepuscolo? Come uscirà il sistema partitico italiano da questa nuova fase di destabilizzazione? Questo quarto Dossier CISE, che raccoglie contributi apparsi sul sito web del Cise prima e dopo le elezioni, fornisce una prima analisi del voto, presentando elaborazioni su dati aggregati, stime dei flussi elettorali, alcune prime analisi su dati di sondaggio, nonché una panoramica dei nuovi eletti e un’appendice ricca di tabelle e mappe riassuntive del risultato elettorale. Come i precedenti Dossier, si tratta di uno strumento prodotto rapidamente all’indomani del voto, con l’intento di suggerire primi spunti di interpretazione da approfondire in seguito, cercando di contribuire alla lettura di un risultato elettorale cruciale, in una delicata fase di cambiamento del sistema partitico italiano
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