Metodi per l'estrazione di caratteristiche di molecole mediante la microscopia a forza atomica

Questo lavoro si propone di estrarre informazioni su molecole biologiche fissate su un substrato utilizzando la microscopia AFM. Il limite naturale di questa microscopia è dato dagli effetti distorsivi della convoluzione punta-campione. Per superare questo limite, il presente lavoro propone un aproccio inverso rispetto a quelli classici; Invece di operare direttamente sull’imaging molecolare si costruisce un modello della molecola e viene simulata la microscopia, introducendo le distorsioni tipiche dell’AFM. Il confronto (basato sulla mutua informazione) viene reiterato raffinando ad ogni iterazione i parametri iniziali. La simulazione della microscopia afm comprende la ricostruzione del tip

Key issues in processing metal-supported proton conducting anodes for SOFCs applications

BaCe0.65Zr0.2Y0.15O3-δ(BCZY) have been recently proposed for IT-SOFCs due to its high proton conductivity. A the same time considerable efforts are directed towards the development of metal-supported cells. The combination of the potential advantages offered by either proton conductors based cells and metal supported configuration has never been explored before. In this work the technological issues to produce proton conducting BCZY-Ni anodes stainless steel-supported were carefully investigated. A tailored porous metal support was produced by tape casting. Afterwards the anode was deposited by screen printing and the resulting bilayer sintered in reducing atmosphere. Each step of the production process was throughly investigated. A cations interdiffusion between the metallic support and the anodic layer was observed in all the range of temperatures considered. The influence of a CeO2 barrier layer and anode thickness on the cations diffusion and a successful production of planar crack-free anode was deeply analyze

Boosting infrared energy transfer in 3D nanoporous gold antennas

The applications of plasmonics to energy transfer from free-space radiation to molecules are currently limited to the visible region of the electromagnetic spectrum due to the intrinsic optical properties of bulk noble metals that support strong electromagnetic field confinement only close to their plasma frequency in the visible/ultraviolet range. In this work, we show that nanoporous gold can be exploited as a plasmonic material for the mid-infrared region to obtain strong electromagnetic field confinement, co-localized with target molecules into the nanopores and resonant with their vibrational frequency. The effective optical response of the nanoporous metal enables the penetration of optical fields deep into the nanopores, where molecules can be loaded thus achieving a more efficient light–matter coupling if compared to bulk gold. In order to realize plasmonic resonators made of nanoporous gold, we develop a nanofabrication method based on polymeric templates for metal deposition and we obtain antenna arrays resonating at mid-infrared wavelengths selected by design. We then coat the antennas with a thin (3 nm) silica layer acting as the target dielectric layer for optical energy transfer. We study the strength of the light–matter coupling at the vibrational absorption frequency of silica at 1240 cm−1 through the analysis of the experimental Fano lineshape that is benchmarked against identical structures made of bulk gold. The boost in the optical energy transfer from free-space mid-infrared radiation to molecular vibrations in nanoporous 3D nanoantenna arrays can open new application routes for plasmon-enhanced physical–chemical reactions

Densification behaviour of screen printed Gadolinia doped Ceria films: effect of CuO

The effect of CuO on the densification of a Gadolinia doped Ceria (Ce0.8Gd0.2O2-d, GDC) deposited by screen printing on a GDC/NiO anode produced by tape casting was considered aiming to a complete co-firing of the anode-electrolyte half cell. A comparative study on a CuO-doped and undoped GDC revealed that the effect of CuO is strongly dependent on the thickness of the deposited layer and can lower of more than 100?C the temperature of co-firing of the anode-electrolyte half-cell. Chemical analysis did not reveal traces of CuO on the sintered GDC layer indicating that the oxide should evaporate from the electrolyte layer during sintering not affecting in this way its electrochemical propertie

Acute Effects Of Triiodothyronine T. (T3) Replacement Therapy in Patients with Chronic Heart Failure and Low-T3 Syndrome: A Randomized, Placebo-Controlled Study

Context: Low-T3 syndrome is a predictor of poor outcome in patients with cardiac dysfunction. The study aimed to assess the short-term effects of synthetic L-T3 replacement therapy in patients with low-T3 syndrome and ischemic or nonischemic dilated cardiomyopathy (DC). Design:Atotal of 20 clinically stable patients with ischemic (n12) or nonischemic (n8) DC were enrolled. There were 10 patients (average age 72 yr, range 66–77; median, 25–75th percentile) who underwent 3-d synthetic L-T3 infusion (study group); the other 10 patients (average age 68 yr, range 64–71) underwent placebo infusion (control group). Clinical examination, electrocardiography, cardiac magnetic resonance, and bio-humoral profile (free thyroid hormones, TSH, plasma renin activity, aldosterone, noradrenaline, N-terminal-pro-B-Type natriuretic peptide, and IL-6) were assessed at baseline and after 3-d synthetic L-T3 (initial dose: 20 g/m2 body surfaced) or placebo infusion. Results: After T3 administration, free T3 concentrations increased until reaching a plateau at 24–48 h (3.43, 3.20–3.84 vs. 1.74, 1.62–1.93 pg/ml; P 0.03) without side effects. Heart rate decreased significantly after T3 infusion (63, 60–66 vs. 69, 60–76 beats per minute; P 0.008). Plasma noradrenaline (347; 270–740 vs. 717, 413–808 pg/ml; P 0.009), N-terminal pro-B-Type natriuretic peptide (3000, 438-4005 vs. 3940, 528-5628 pg/ml; P0.02), and aldosterone (175, 152–229 vs. 231, 154–324 pg/ml; P 0.047) significantly decreased after T3 administration. Neurohormonal profile did not change after placebo infusion in the control group. After synthetic L-T3 administration, left-ventricular end-diastolic volume (142, 132–161 vs. 133, 114–158 ml/m2 body surface; P 0.02) and stroke volume (40, 34–44 vs. 35, 28–39 ml/m2 body surface; P 0.01) increased, whereas external and intracardiac workload did not change. Conclusions: In DC patients, short-term synthetic L-T3 replacement therapy significantly improved neuroendocrine profile and ventricular performance. These data encourage further controlled trials with more patients and longer periods of synthetic L-T3 administration

Chemical and spectroscopic characterization of humic acids extracted from the bottom sediments of a Brazilian subtropical microbasin

International audienceHumic substances (HS) perform a fundamental role in aquatic environments, exhibiting different levels of reactivity in retaining metal ions and organic pollutants. Also, they control the primary production of these ecosystems and act in the carbon sequestering process. In order to improve our understanding vis-à-vis the structural and functional features of HS from aquatic systems, this study aimed to chemically and spectroscopically characterize humic acids (HA) isolated from bottom sediment samples of a stream in a Brazilian subtropical microbasin by elemental analysis, and infrared (FT-IR), ultraviolet and visible (UV-Vis) and solid-state 13C nuclear magnetic resonance (CP-MAS 13C NMR) spectroscopies, thermogravimetry (TG), and scanning electron microscopy (SEM). Although all samples originated from the same environment, the data showed that the HA have distinct chemical and spectroscopic properties, and that the location and characteristics of the sampling points from which the sediments were collected played an important role in the differences observed. Furthermore, vascular plant matter is probably the main contributor to these samples

Myocardial fibrosis as a key determinant of left ventricular remodeling in idiopathic dilated cardiomyopathy: a contrast-enhanced cardiovascular magnetic study

In idiopathic dilated cardiomyopathy, there are scarce data on the influence of late gadolinium enhancement (LGE) assessed by cardiovascular magnetic resonance on left ventricular (LV) remodeling