3 resultados para G 0

em AMS Tesi di Dottorato - Alm@DL - Università di Bologna


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In the last decades significant improvements has been reached in short term graft survival, conversely long-term graft survival in still an open challenge for the scientific community. One of the major causes of long term graft loss is represented by chronic- active antibody mediated rejection (cAMR), a recently identified entity whose diagnosis is based on laboratoristic and histologic elements: the presence of DSA associated to specific morphological lesions as inflammation and microvascular damage associated or not to C4d deposition. Treatment of cAMR is an open field of debate. Tocilizumab, an anti-IL6 monoclonal antibody has been recently proposed as a first line treatment for cAMR, showing encouranging results. We describe our monocentric experience using Tocilizumab as first-line therapy for cAMR. Graft function (eGFR), proteinuria and DSA have been evaluated every 6 month for 24 months; histology have been performed after 12 months of treatment. No adverse events have been observed during study period. 12 patients completed the study with a follow-up of 24 months. Kidney function showed a worsening during follow-up that reaches statistical significance at 12 and 24 months (eGFR from 32.2±13.9 ml/min to 26.9±13 ml/min), but far less than expected for these kind of patients. 4 patients (30%) reached ESRD during follow-up, 3 requiring renal replacement therapy. We did not observed any statically significant variation in proteinuria and in DSA MFI levels. From a histological point of view, we observed a significant improvement in active cAMR lesions (C4d deposition and Acute tissue injury (MTA, g>0/ptc>0, v>0) and no progression among chronic lesions (Transplant glomerulopathy, PTC multilayering and aterial intimal fibrosis) Tocilizumab shown good results, with a stabilization of graft function, a reduction in kidney inflammation and active lesions in kidney biopsy and not allowing progression of chronic lesions.

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The rotational and ro-vibrational spectroscopy analysis of selected molecules of astrophysical importance, namely formaldehyde, mono-deuterated hydrogen sulfide, cyanoacetylene, deuterated cyanoacetylene, aminoacetonitrile, allylimine, and 2-aza-1,3-butadiene, has been presented in this thesis. For formaldehyde and mono-deuterated hydrogen sulfide, which are well-known interstellar molecules, a detailed Measured Active Rotational–Vibrational Energy Levels (MARVEL) analysis has been performed. For both of them, the MARVEL approach has been used to accurately derive the rotational and ro-vibrational energy levels from the experimental data available in the literature combined with new millimeter-wave measurements. Overall, the MARVEL analysis span a huge frequency range, from millimeter-wave to infrared (IR). For allylimine and 2-aza-1,3-butadiene, the pure rotational spectrum has been extended to the millimeter-wave region. The outcome of these two studies is the derivation of very accurate spectroscopic parameters that allow the accurate prediction of their rotational transitions over a large frequency range. For allylimine, this line catalog allowed the tentative detection of two isomers of allylimine (Ta and Ts) towards the G+0.693 molecular cloud. In addition to rotational spectroscopy, high-resolution IR spectra of interstellar molecules play also of pivotal role for the exploration of astromomical objects. For these reasons, high-resolution IR spectra of cyanoacetylene, deuterated cyanoacetylene, and aminoacetonitrile have been investigated. The precise spectroscopic constants of several vibrational excited states of these three molecules have been derived from the assignment of newly recorded IR spectra. Given the fact that all these three molecules are potentially present in Titan’s atmosphere, their ro-vibrational transitions can be considered unvaluable tools for their search, which might also be extended to other planetary atmospheres.

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The rotational spectroscopy of several sulfur bearing molecules and their 1:1 water complex, cysteamine, cysteamine monohydrate, 1-thioglycerol and 1-propanethiol were studied in the micro-wave and (or) millimeter-wave range. Precise laboratory spectra and conformational information were obtained. For cysteamine, the conformational space (at the B3LYP-GD3(BJ)/Def2-TZVP level) and the measurement and analysis of its rotational spectra in the 6 - 18 and 59.6 - 120 GHz are reported. The hyperfine structure of the rotational spectra was observed and analyzed for the first time. Based on the measured spectra, a search of the different conformers of cysteamine was performed toward the G+0.693-0.027 molecular cloud. We computed the upper limit of the ratio of ethanolamine to cysteamine, which is >0.8−5.3. For the cysteamine monohydrate, the conformational space was explored (at the B3LYP-GD3(BJ)/Def2-TZVP level). The rotational spectra of the cysteamine monohydrate complex have been assigned in the frequency range 6 – 18.5 GHz. The global minimum, Conf A1, was the only observed one. The 34S isotopologue of Conf A1 was observed in natural abundance, while 18O isotopologue was detected by introducing the H218O. In this conformer, the water molecule plays both proton donor and acceptor roles, forming a OHw···N interaction, a SH···Ow interaction and a CH···Ow interaction. The conformational space of 1-thioglycerol has been characterized by quantum mechanical calculation and its rotational spectrum has been recorded and analyzed in the frequency range 59.6 - 78.4 GHz. The global minimum of 1-thioglycerol is gTgGg’ and were detected together with gTg’Tg and gGgGg, while the two detected conformers are gGgGg’ and tGgGg. The high-resolution rotational spectrum of 1-propanethiol in the frequency range 59.6 – 78.4 GHz was measured. Two conformers, Gg and Tg, were observed and their spectra were analyzed. Considering the overall conformational space calculated at the B3LYP-GD3(BJ)/Def2-TZVP level they are among the lowest energy conformers.