[en] To investigate the mechanisms of erythromycin cholestasis, the effects of erythromycin estolate (EE) on the excretory function of the isolated perfused rat liver and on liver plasma membrane (LM) preparations were studied and compared to those of erythromycin base (EB) and lauryl sulfate (LS), added alone or in combination. EE (at 125 to 200 microM) caused dose-dependent reductions of bile and perfusate flows, bile acid (BA) excretion, and biliary BA concentration. The alterations of the excretory function were only in part due to the decreased perfusate flow. In contrast, both 200 and 300 microM concentrations of EB elicited similar choleretic responses, which were presumably related to the osmotic activity of the drug excreted in the bile. LS did not affect hepatic excretory functions. However, the simultaneous addition of EB and LS resulted in a rate of bile flow lower than that observed with EB alone. EE, but not EB, increased canalicular permeability to [14C]sucrose as measured by bile to plasma (B:P) ratio. Neither drugs altered [14C]erythritol B:P ratio. In LM preparations both Na+,K+- and Mg2+-ATPase activities were inhibited in a dose-dependent manner by EE, but not by EB. The data suggest that EE could affect bile flow by inhibiting cotransport of Na+ and BA and by altering LM permeability and support the view that the effect of erythromycins on the liver may be related to their surface activity
Journal
[en] Attention is focused on the effects of correlations in the initial state, on the influence of the mutual interaction between the two outgoing nucleons and on the treatment of the Δ current. It is shown that the investigation of different mutually supplementing kinematics is necessary to resolve the uncertainties in the theoretical ingredients and extract clear and unambiguous information on correlations. (author)
Journal
Dokladi na BYaD; ISSN 1310-8727; 
; v. 10(2); p. 136-145
; v. 10(2); p. 136-145
[en] Maturation test were carried out on heaps of MSWI bottom ash. The testing was carried out over a six-month period in autumn and winter. The aim was to verify, in a pilot plant, the feasibility of the maturation process in relation to a reduction of the release of lead in the aqueous phase within normative limits for landfill. The evolution of the maturation mechanism has been studied in function of time, characteristics of the ashes, and behaviour according to Italian conformity test UNI 10802. To estimate the influence of weather and preparation, heaps were prepared with different heights using both untreated ash and ash after sieving, in both exposed and covered heaps. During the testing period the release of lead, cooper, chlorides, conductivity, ph, alkalinity, calcium, sulphates, Doc were measure. Coupling this test with the meteorological data, it was possible to characterize the physical and chemical mechanisms involved in the maturation and to verify the role of hydroxide carbonatation and its controlling factors. The results have made possible to define outlines to optimise the treatment. We suggest a maturation period in heaps of untreated ash, then sieving and recovery of the iron and finally a second period of post maturation of the sieved ashes (<30 mm)
[it]
Si riportano i risultati di una sperimentazione eseguita in campo per valutare gli effetti della maturazione in cumulo di scorie pesanti derivanti dall'incenerimento di RSU sul rilascio di metalli pesanti. La sperimentazione e durata sei mesi corrispondenti al periodo autunnale e invernale. L'obbiettivo e quello di verificare in particolare l'ottimizzazione del processo in relazione alla riduzione della lisciviabilita del piombo entro i limiti normativi previsti per l'ammissibilita in discarica. Si e pertanto studiato il processo attraverso l'evoluzione nel tempo, delle caratteristiche delle scorie, ed in particolare del loro comportamento al test di cessione UNI 10802. AI fine di valutare l'influenza delle condizioni esterne e delle modalita operative, sono stati realizzati cumuli di differente altezza all'aperto e sotto tettoia, utilizzando sia scorie tal quali sia scorie dopo vagliatura (<30 mm). Per l'intero periodo sono state monitorate precipitazioni e temperature. I parametri monitorati, sono: piombo, rame, cIoruri, conducibilita, pH, alcalinita, calcio, solfati, DOC. Dall'insieme dei risultati analitici e stato possibile individuare i meccanismi chimico fisici, noti dalla letteratura, che portano alla immobilizzazione del piombo nel breve e medio termine; in particolare si e evidenziato il ruolo fondamentale della carbonatazione e dei suoi fattori controllanti. Dall'insieme dei risultati ottenuti e possibile proporre degli schemi operativi per l'ottimizzazione del trattamento. Questi prevedono una prima fase di maturazione in cumulo con scorie tal quali, la successiva vagliatura e il recupero del ferro, ed eventualmente una seconda fase di post maturazione della scoria vagliata (<30 mm)Journal
RS. Rifiuti Solidi; ISSN 0394-5391; ; v. 19(5); p. 294-304
; v. 19(5); p. 294-304
[en] The origin of threading dislocations (TDs) in nitride films is not completely understood but it is well established that they degrade the film properties. This work investigates the assumption that they arise from the interface between the film and sapphire substrate owing to small in-plane rotations between nitride domains. Bollmann’s formalism is first used to determine the characteristics of dislocations at the nitride film/sapphire interface that compensate both for the parametric misfit and a small in-plane rotation of the film as frequently observed. It is shown that the dislocation density and line direction depend on the rotation angle. When islands grow and coalesce in the nucleation layer, some interfacial dislocations orientate along [0001] in the boundaries between domains and transform to so-called TDs. The amount of TDs lying in the boundaries between nitride domains is calculated as a function of the rotation angle. Estimations of TD density in the nucleation layer are deduced for a range of domain sizes and compared with experimental values of the literature.
Journal
[en] Polycrystalline tin-doped indium oxide (ITO) thin films were prepared by pulsed laser deposition (PLD) with an ITO (In2O3-10 wt.% SnO2) target and deposited on borosilicate glass substrates. By changing independently the deposition temperature and the oxygen pressure, a variety of microstructures were deposited. These different microstructures were mainly investigated not only by transmission electron microscopy (TEM) with cross-section and plan-view electron micrographs, but also by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction. Composition changes in ITO thin films grown under different deposition conditions were characterized by energy dispersive X-ray spectroscopy (EDX). The optical and electrical properties were studied respectively by UV-visible spectrophotometry and a four-point probe. The best compromise in terms of high transmittance (T) in the visible range and low resistivity (ρ) was obtained for films deposited between 0.66 and 2 Pa oxygen pressure (PO2) at 200 oC substrate temperature (Ts). The influence of PO2 and Ts on the microstructure and ITO film properties is discussed.
Journal
[en] We propose a multi-technique approach based on in-vacuum synthesis of metal oxides to optimize the memristive properties of devices that use a metal oxide thin film as insulating layer. Pulsed Microplasma Cluster Source (PMCS) is based on supersonic beams seeded by clusters of the metal oxide. Nanocrystalline TiO2 thin films can be grown at room temperature, controlling the oxide stoichiometry from titanium metal up to a significant oxygen excess. Pulsed Electron beam Deposition (PED) is suitable to grow crystalline thin films on large areas, a step towards producing device arrays with controlled morphology and stoichiometry. Atomic Layer Deposition (ALD) is a powerful technique to grow materials layer-by-layer, finely controlling the chemical and structural properties of the film up to thickness of 50-80 nm. We will present a few examples of metal-insulator-metal structures showing a pinched hysteresis loop in their current-voltage characteristic. The structure, stoichiometry and morphology of the metal oxide layer, either aluminum oxide or titanium dioxide, is investigated by means of scanning electron microscopy (SEM) and by Raman scattering
Journal
[en] Polycrystalline tin-doped indium oxide (ITO) thin films were prepared by Pulsed Laser Deposition with an ITO (In2O3-10 wt.% SnO2) ceramic target and deposited on transparent borosilicate glass substrates between room temperature (RT) and 400 °C. The RT grown specimen was structurally investigated by Transmission Electron Microscopy, Scanning Electron Microscopy, Atomic Force Microscopy and X-Ray Diffraction. It contained both amorphous and crystalline phases. The electro-optical properties of the RT-grown sample were almost similar to those of the samples grown at higher temperatures. Finally, Scanning Transmission Electron Microscopy–Valence Electron Energy Loss Spectroscopy was used to derive locally dielectric properties which were compared with ellipsometry measurements in the 1.5–5.5 eV range using a Tauc–Lorentz model. - Highlights: ► Indium tin oxide thin films contained both amorphous and crystalline phases. ► Dielectric properties were derived both at the nanoscale and macroscale. ► Nanoscale and macroscale measurements agreed in the predominant amorphous phase.
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