497 research outputs found
L’enigma dei raggi cosmici: le più grandi energie dell’universo
No full textGrazie ad avventurosi studi fu possibile dimostrare un secolo fa che parte della radiazione naturale che si osserva sulla Terra è di natura extraterrestre: era la scoperta dei cosiddetti “raggi cosmici”, particelle che arrivano da misteriosi acceleratori nell’universo, probabilmente buchi neri supermassicci e resti di supernova, a energie anche centinaia di milioni di volte di quelle a cui riusciamo a produrle con i più potenti acceleratori della Terra. A cent’anni dalle prime scoperte questo libro si propone, con l’aiuto di documenti scoperti recentemente, di raccontare la vera storia di questa appassionante avventura scientifica e le frontiere dell'esplorazione dei raggi cosmici
Therapeutic drug monitoring of recent antidepressants in patients under polypharmacy
No full textThe introduction into clinical practice of the so-called second generation antidepressants has improved the treatment of depression, since these drugs, compared to the first generation antidepressants (such as imipramine and clomipramine), show a more favourable safety profile with respect to cardiovascular effects, whilst maintaining efficacy. Nevertheless, patients treated with these newer antidepressants can present undesired effects, including serotonin syndrome, sedation, body weight changes, sexual dysfunction and suicidal ideation. Therefore, with the aim of reducing the risk for toxic/side effects, therapeutic drug monitoring (TDM) of second generation antidepressants is advisable, particularly in case of patients under polypharmacy. During the last years, a number of methods have been developed in our Laboratory for the accurate determination of antidepressant drugs and their metabolites in plasma samples obtained from patients, including drugs belonging to different classes of second-generation antidepressants (SSRI, NaSSA, SNRI). Sertraline, together with its main metabolite N-desmethylsertraline, can be analysed in plasma samples using a method based on capillary electrophoresis with laser-induced fluorescence (LIF) detection. The method employs a 488 nm wavelength laser and a sample pre-treatment procedure consisting in solid-phase extraction followed by derivatisation with fluorescein isothiocyanate. The high selectivity obtained allows the determination of sertraline in plasma samples from patients under polypharmacy.
Capillary electrophoresis with diode-array detection has been employed for the enantioselective determination of mirtazapine and its active metabolite N-desmethylmirtazapine in human plasma. The method is quite fast: after a solid-phase extraction procedure, the electrophoretic run lasts 2.5 min.
HPLC with fluorescence detection has been used for the determination of venlafaxine together with its main metabolite O-desmethylvenlafaxine, while HPLC coupled to UV detection was employed for the analysis of duloxetine in plasma of depressed patients
The Italian LCA Network: objectives and activities of the Working Group on Tourist Services
No full textPlasma membrane gamma-glutamyltransferase activity facilitates the uptake of vitamin C in melanoma cells.
No full textAdequate cellular transport of ascorbic acid (AA) and its oxidation product dehydroascorbate (DHA) is
assured through specific carriers. It was shown that vitamin C is taken up as DHA by most cell types, including cancer
cells, via the facilitative GLUT transporters. Thus, AA oxidation to DHA can be considered a mechanism favoring
vitamin C uptake and intracellular accumulation. We have investigated whether such an AA-oxidizing action might be
provided by plasma membrane g-glutamyltransferase (GGT), previously shown to function as an autocrine source of
prooxidants. The process was studied using two distinct human metastatic melanoma clones. It was observed that the
Me665/2/60 clone, expressing high levels of membrane GGT activity, was capable of effecting the oxidation of
extracellular AA, accompanied by a marked increase of intracellular AA levels. The phenomenon was not observed with
Me665/2/21 cells, possessing only traces of membrane GGT. On the other hand, AA oxidation and stimulation of cellular
uptake were indeed observed after transfection of 2/21 cells with cDNA coding for GGT. The mechanism of GGTmediated
AA oxidation was investigated in acellular systems, including GGT and its substrate glutathione. The process
was observed in the presence of redox-active chelated iron(II) and of transferrin or ferritin, i.e., two physiological iron
sources. Thus, membrane GGT activity—often expressed at high levels in human malignancies—can oxidize
extracellular AA and promote its uptake efficiently
[C. Iu]lius Menodorus, il primo tribuno militare dalla provincia d’Asia
Get PDFA funerary inscription found at Ephesus records the cursus of a certain Menodorus, a fresh Roman citizen inscribed in the tribe Cornelia as well as praefectus fabrum and tribunus militum during his lifetime. The author believes that he must be identified with the Menodorus/Menas recorded by our literary sources as a sea-captain in the war against Sextus Pompeius, who at a certain point switched sides and was thence rewarded by Octavian with the inclusion in the ordo equester.A funerary inscription found at Ephesus records the cursus of a certain Menodorus, a fresh Roman citizen inscribed in the tribe Cornelia as well as praefectus fabrum and tribunus militum during his lifetime. The author believes that he must be identified with the Menodorus/Menas recorded by our literary sources as a sea-captain in the war against Sextus Pompeius, who at a certain point switched sides and was thence rewarded by Octavian with the inclusion in the ordo equester
Raggi cosmici, ieri, oggi, domani
Get PDFScoperti all'inizio del XX secolo, i raggi cosmici sono particelle di energie molto elevate (fino a un miliardo di TeV) che raggiungono la Terra in provenienza da acceleratori extraterrestri il cui meccanismo di funzionamento non è ancora pienamente compreso. Sono un potente strumento per indagare la fisica fondamentale, e in modo complementare possono spiegarci interessantissimi fenomeni astrofisici, in particolare quelli che avvengono in prossimità di oggetti compatti. Possono far progredire la nostra conoscenza dell'Universo su larga scala, dalla cosmologia alla ricerca sulle origini della vita. La rinnovata attenzione degli scienziati per i raggi cosmici ha portato negli ultimi anni al fiorire di attività sperimentali e teoriche nei campi chiamati fisica astroparticellare e astronomia multimessaggero
Due bozzetti in terracotta per 'Angeli con nuvole' di Antonio Raggi e di Giuseppe Mazzuoli. Sulla funzione didattica dei modelli preparatori nella Roma chigiana, in 'Prospettiva', 145, 2012, pp. 82-98
No full textSi attribuiscono due bozzetti in terracotta, l'uno con 'Angelo in volo' a Antonio Raggi, l'altro con 'Due con nuvole' a Giuseppe Mazzuoli. Breve excursus sulla funzione didattica di simili manufatti
High precision measurement of the form factors of the semileptonic decays K± → π0l±+ν at NA48/2
No full textThe NA48/2 experiment presents preliminary measurements of the form factors of the charged kaon semileptonic decays, based on 4.0 million K e3± and 2.5 million Kμ3 ± decays, both with negligible background. The Ke3 and Kμ3 results are in good agreement allowing for a combined result which matches the precision of the current world average on the vector and scalar form factors. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
Measurement of BR(Ke2)/BR(Kμ2) with NA62
No full textThe NA62 experiment at CERN SPS collected, during 2007 run, the world largest sample of K±leptonic decays in order to test lepton universality, by measuring the ratio: RK = Γ(K ± → e±ν)/ Γ (K ± → μ±) = γ(Ke2)/ Γ (Kμ2) (1) Being helicity suppressed, due to V-A structure of the charged weak current, RK is sensitive to non-SM effects. The preliminary result of the analysis based on 51089 K± → e ±νcandidates, extracted from a sub-sample of the data set, is: RK = (2.500±0.016) · 10-5, consistent with Standard Model predictions. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
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