117,612 research outputs found
scheda bibliografica di: Alfonsi L., Barberi Squarotti G., Mariotti S., Momigliano A., Plebe A., Cinque studi su Augusto Rostagni, Torino 1972
No full textConformation of intercalated DNA plasmids investigated by circular dichroism and dynamic light scattering
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Cell transfer of information via miR-loaded exosomes: a biophysical approach
No full textA new communication route among cells was reported in recent years, via extracellular vesicles and their cargo. Exosomes in particular are attracting increasing interest as privileged mediators of this cell communication route. The exosome-mediated transfer of nucleic acids, especially of microRNAs, is particularly promising for their use both as biomarkers of pathologies and as a therapeutic tool. Here, a simplified model of interaction among cells, microRNAs and vesicles is studied using a biophysical approach. A synthetic and fluorescent microRNA (i.e. miR-1246 conjugated with TAMRA) was selected to model cell communication, monitoring its internalization in cells. The fluorescent miR-1246, either naked or included in synthetic or natural vesicles, was incubated with human breast adenocarcinoma cells (MCF7) for different times. A comparison between this human microRNA and its DNA copy or an exogenous microRNA (from Caenorhabditis elegans) allowed assessment of the specificity of the information transfer through microRNAs, and especially associated with exosomes. The uptake of naked miR-1246 was indeed higher both in terms of number of targeted cells and intensity of fluorescence signal with respect to the other nucleic acids tested. The same occurred with miR-1246 loaded exosomes, evidencing a specific uptake only partially due to the lipidic components and present only when the human microRNA was loaded in exosomes, which were themselves derived from the same MCF7 cells
Epididymis microlithiasis and semen abnormalities in young adult kidney transplant recipients
No full textMicrolithiasis of the epididymis is a rare ultrasound finding in the general population, but the incidence of calcifications in various organs of patients with end-stage renal disease (ESRD) is extremely high. The aim of this study was to describe epididymal microlithiasis in 22 previously dialysed patients who received kidney transplantations at a median age of 19years (range 9-30). The patients underwent scrotum ultrasonography, semen analysis and laboratory tests (renal function, sexual hormones, Ca, P and PTH) and were administered the International Index of Erectile Function questionnaire. Seventeen presented calcifications of the epididymis, two of whom had concomitant testicular calcifications; a further three patients had isolated testicular calcifications without epididymis involvement. It was not possible to investigate the fertility of all of the patients but 12 of the 13 whose semen was analysed showed abnormalities: five were azoospermic and seven oligospermic with various degrees of morphological anomalies. To the best of our knowledge, these are the first published data concerning the prevalence of epididymal calcifications in young dialysed patients undergoing renal transplantation. Epididymal microlithiasis and infertility were common findings and so performing a spermiogram and preserving semen before ESRD for future paternity may be good advice in this selected population
On‐chip purification of tetracycline from food matrices
No full textAntibiotics are widespread both to treat human and animal diseases and to improve growth in food animals. However, their overuse in food-producing animals has led to critical issues for human health, such as the direct toxicity and the development of antibiotic-resistant bacterial strains. Therefore, the identification of traces of antibiotic in food before entering the market has became extremely important and brought out the need for novel bioanalytical methods and protocols. To meet this need, here, a microfluidic system was set up for the purification of tetracycline (TC) from raw milk, honey, and eggs. The system is based on the use of magnetic beads exposing copper ions, which are loaded in a microfluidic chamber and actuated by a ready-made device. Tetracycline is captured by copper ions present on the microbeads, purified from the unwanted raw material present in the initial sample and recovered by a suitable elution solution. Different elution solutions were tested and results were evaluated by X-ray photoelectron spectroscopy (XPS) and visible spectrometry. The microfluidic system was successfully employed for the purification of TC from raw milk, honey, and eggs after an initial dilution in buffer. The overall protocol was, therefore, demonstrated to efficiently purify tetracycline, laying the bases for a future implementation of in-field on-chip tests
Effect of Methoxy Substituents on the Structural and Electronic Properties of Fluorinated Cyclobutenes : A Study of Hexafluorocyclobutene and its Vinyl Methoxy Derivatives by XRD and Periodic DFT Calculations
No full textThe effect of the methoxy substituent on the structure, crystal packing, and electrostatic properties of
hexafluorocyclobutene (C4F6) was investigated in the solid-state with DFT-B3LYP calculations. Full geometry
optimizations were done for the parent compound and its two vinyl methoxy derivatives C4F5OCH3 and
C4F4(OCH3)2, starting from the structures obtained by single-crystal X-ray diffraction at low temperature. A full topological analysis, followed by the calculation of several electrostatic properties, was performed on the periodic electron density using the quantum theory of atoms in molecules. Eventually, the cohesive energies
of the three crystals were estimated. In the cyclobutene plane, the methoxy substitution yields a significant
electronic rearrangement involving the π-electrons. The solid-state (periodic) results agree with those obtained
by gas-phase calculations on C4F6 and its derivatives at a comparable level of theory. It was found that the substitution of one or two vinylic fluorine atoms with the OCH3 group considerably influences the molecular
dipole moment, which undergoes an enhancement in both the solid and the gas phase as large as 200% and
235% for C4F5OCH3 and C4F4(OCH3)2, respectively, with respect to that calculated for C4F6. The charge
rearrangement due to the substituents provides a significant electrostatic contribution to the lattice energy,
and in turn it can be related to the change in the observed crystal packing on going from C4F6 (space group P21/c) to both of its derivatives (space group P1bar). It is also shown that the dispersion energy significantly contributes to the lattice stability in all three compounds. Since the DFT calculations, in the limit of large
separations, entirely miss the dispersion term, this was estimated by applying a recently proposed dampening function to the semiempirical atom-atom C6 R-6 potentials in the mainframe of Spackman’s energy decomposition scheme for Mulliken multipoles
Gestione sostenibile della trota marmorata (S.t. marmoratus) nel bacino dell'Adige: caratterizzazione genetica, fenotipica ed ecologica finalizzata alla conservazione
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