The role of copper (Ii) on kininogen binding to tropomyosin in the presence of a histidine–proline-rich peptide

The antiangiogenic activity of the H/P domain of histidine–proline-rich glycoprotein is mediated by its binding with tropomyosin, a protein exposed on endothelial cell-surface during the angiogenic switch, in presence of zinc ions. Although it is known that copper ion serum concentration is significantly increased in cancer patients, its role in the interaction of H/P domain with tropomyosin, has not yet been studied. In this paper, by using ELISA assay, we determined the modulating effect of TetraHPRG peptide, a sequence of 20 aa belonging to H/P domain, on the binding of Kininogen (HKa) with tropomyosin, both in absence and presence of copper and zinc ions. A potentiometric study was carried out to characterize the binding mode adopted by metal ions with TetraHPRG, showing the formation of complex species involving imidazole amide nitrogen atoms in metal binding. Moreover, circular dichroism showed a conformational modification of ternary systems formed by TetraHPRG, HKa and copper or zinc. Interestingly, slight pH variation influenced the HKa-TetraHPRG-tropomyosin binding. All these results indicate that both metal ions are crucial in the interaction between TetraHPRG, tropomyosin and HKa

Determination of the size distribution of non-spherical nanoparticles by electric birefringence-based methods

The in situ determination of the size distribution of dispersed non-spherical nanoparticles is an essential characterization tool for the investigation and use of colloidal suspensions. In this work, we test a size characterization method based on the measurement of the transient behaviour of the birefringence induced in the dispersions by pulsed electric fields. The specific shape of such relaxations depends on the distribution of the rotational diffusion coefficient of the suspended particles. We analyse the measured transient birefringence with three approaches: the stretched-exponential, Watson-Jennings, and multiexponential methods. These are applied to six different types of rod-like and planar particles: PTFE rods, goethite needles, single- and double-walled carbon nanotubes, sodium montmorillonite particles and gibbsite platelets. The results are compared to electron microscopy and dynamic light scattering measurements. The methods here considered provide good or excellent results in all cases, proving that the analysis of the transient birefringence is a powerful tool to obtain complete size distributions of non-spherical particles in suspension.Financial support of this investigation by Junta de Andalucía, Spain (grant No. PE2012-FQM0694) and University of Granada (Program “Proyectos de investigación precompetitivos”) is gratefully acknowledged

Production and energy transformation of herbaceous biomasses irrigated with treated wastewater \u2013 first results

The first results on experiments with the goal of an agronomical, environmental, energetic and economical evaluation about the biomass production from herbaceous species irrigated with treated wastewater are reported in this paper. The experiments were conducted in collaboration with four Italian universities (within a National Research Project, PRIN 2007): Padova, Bologna, Reggio Calabria and Catania. Six main herbaceous species were tested by each university in their own experimental fields. In particular, each university planted four species common to all units, one in the biggest plot and the others in three smaller plots. Physical, chemical and microbiological analyses were carried out on wastewater samples. In particular, the following parameters were evaluated: pH, electric conductivity, TSS, BOD5, COD, total phosphorus, ammonia, nitrite, nitrate and total nitrogen. From an agronomic point of view, the growth dynamics, the translocations of assimilates between aerial and subterranean organs, and the different species productivity were analysed. On the top part of the plants, the average height, the biomass production, the moisture content at the harvesting and the heating values were measured

Effects of wastewater irrigation on giant reed (Arundo donax L.) populations biomass production in different Mediterranean environments.

The competition for freshwater between agricultural, industrial, and civil uses has greatly intensified in many Mediterranean areas characterized by prolonged dry seasons. Agriculture accounts for 80% of all water consumption. Efficient use of water for crop irrigation and reuse of scarce quality waters is therefore needed for the conservation of this limited resource. Arundo donax L., a rhizomatous widespread spontaneous plant in Mediterranean regions, is considered among the species at high aptitude for biomass buildup. The aim of this study was to evaluate biomass production of arundo irrigated with different low quality water, at full ETp restitutions, in different Italian environments in relation to three harvest dates. Moreover the combustion data, moisture content, and heating values were measured. The average dry matter production, in the second year cultivation, ranged from 33 to 132 t ha-1. At a plant density of about 10 plant m-2 the highest shoot dry biomass ever measured in Italy was recorded. As concerns the harvest date, the results suggested that arundo reached the maximum biomass yield between November and January. These preliminary results suggest the interest in using treated wastewater for Arundo irrigation. Moreover, the intake of nutrients, present in the irrigation water may reduce fertilization costs and nutrient losses in the environment

Growth kinetics of colloidal Ge nanocrystals for light harvesters

Colloidal Ge nanocrystals (NCs) are gaining increased interest because of their potential application in low-cost optoelectronic and light harvesting devices. However, reliable control of colloidal NC synthesis is often an issue and a deeper understanding of the key-role parameters governing NC growth is highly required. Here we report an extended investigation on the growth of colloidal Ge NCs synthesized from a one-pot solution based approach. A systematic study of the effects of synthesis time, temperature and precursor concentration is elucidated in detail. X-ray diffraction (XRD) analysis reveals the presence of crystalline Ge NCs with a mean size (from 5 to 35 nm) decreasing with the increase of precursor concentration. Such a trend was further confirmed by scanning electron microscopy (SEM) and dynamic light scattering (DLS) analysis. Moreover, the temporal NC size evolution shows a typical saturating behaviour, where characteristic time shortens at higher precursor concentration. All these growth features were satisfactorily simulated by a numerical NC growth model, evidencing that the kinetics of NC growth is controlled by a reaction-limited regime with typical activation energy of 0.7 eV. Finally, light absorption in the visible region and the successful realization of a hybrid photodetector, employing colloidal Ge NCs embedded in PEDOT:PSS polymer, showed the capability of low-cost colloidal Ge to act as light harvester. These results put new understanding for a reliable control of colloidal NC growth and the development of low-cost devices

Biomass production and N uptake of Giant reed under high water and N input in Mediterranean environments.

This study aimed to evaluate the productivity of Arundo donax under good water and N availability coming from non-conventional sources, in different Italian environments (Padova and Bologna in the north, Reggio Calabria and Catania in the south) in relation to three harvest periods (autumn; mid-winter; late-winter). In the northern locations A. donax had already reached maximum productivity the year after transplanting, with 85 and 98 t ha 121 of dry matter at Padova and Bologna, respectively. At Reggio Calabria and Catania a further biomass increase was obtained from the second to third year of cultivation, when production was 62 t ha 121 and 51 t ha 121, respectively. The average dry matter production was 74, 66 and 65 t ha 121 with autumn, mid-winter and late-winter harvesting, respectively. Under N input ranging from 225 to 329 kg ha 121 year 121 at the different locations, the apparent N balance (input\u2013output) was negative except in Catania indicating a great potential of A. donax to provide high N uptake, which would be a useful feature in environments under the European Nitrates Directive