426 research outputs found

    Scanning Probe Microscopy on heterogeneous CaCu3Ti4O12 thin films

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    The conductive atomic force microscopy provided a local characterization of the dielectric heterogeneities in CaCu3Ti4O12 (CCTO) thin films deposited by MOCVD on IrO2 bottom electrode. In particular, both techniques have been employed to clarify the role of the inter- and sub-granular features in terms of conductive and insulating regions. The microstructure and the dielectric properties of CCTO thin films have been studied and the evidence of internal barriers in CCTO thin films has been provided. The role of internal barriers and the possible explanation for the extrinsic origin of the giant dielectric response in CCTO has been evaluated

    The natural history of ankylosing spondylitis in the 21st century

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    Ankylosing spondylitis (AS) is a chronic inflammatory disease that affects the axial skeleton and evolves in stiffnes followed by ankylosis and disability. However, it may be difficult to exactly establish the natural history of the disease and the influence of risk factors of progression, since most patients are treated with various pharmacologic or non-pharmacologic agents, which may potentially influence the natural progression of the disease. In this context, we report here a very interesting case of a 40 year old man, presented to our outpatient clinic, 28 years after the onset of AS. Previously for personal reasons, did not choose not to undergo any treatment. This case allows us to evaluate the natural radiological progression of the disease and the influence of predictive risk factors

    Subclinical atherosclerosis in patients with psoriatic arthritis: a case-control study. Preliminary data

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    Objective: The aim of this study was to evaluate the prevalence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA), correlated with some traditional risk factors of atherosclerosis and with PsA-related disease factors. Methods: Forty-one patients and 41 healthy subjects were evaluated for intima-media thickness (IMT) and flow-mediated dilation (FMD), using carotid duplex scanning. IMT values were expressed like IMT mean (cumulative mean of all the IMT mean) and M-MAX (cumulative mean of all the higher IMT). Subclinical atherosclerosis markers were correlated with age, body mass index (BMI) and blood pressure in both groups, with duration of arthritis, duration of psoriasis, tender and swollen joints, BASDAI (Bath Ankylosing Spondylitis Disease Activity Index), BASFI (Bath Ankylosing Spondylitis Functional Index), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in patients. Results: IMT mean and M-MAX were both higher in PsA patients compared with controls (0.7±0.15 vs 0.62±0.09 mm; p<0.01 and 0.86±0.21 vs. 0.74±0.13 mm; p<0.01 respectively). FMD was smaller in patients than in controls (5.9±2 vs 7.5±2.8%; p<0.01). Univariate analysis showed a correlation between IMT mean and SBP (r=0.217; p=0.05) and a correlation between M-MAX and age (r=0.392; p<0.001), BMI (r=0.252; p<0.05), SBP (r=0.446; p<0.001) in both groups. In PsA patients M-MAX resulted correlated with ESR (r=0.338; p<0.05) and BASDAI (r=0.322; p<0.05). Conclusions: PsA patients exhibited endothelial dysfunctions which is an early marker of subclinical atherosclerosis, as well as an higher IMT. An interesting correlation between M-MAX and PsA activity index (ESR and BASDAI) was found

    Multifragmentation threshold in ^{93}Nb+{nat}Mg collisions at 30 MeV/nucleon

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    We analyzed the 93Nb^{93}Nb on natMg^{nat}Mg reaction at 30 MeV/nucleon in the aim of disentangling binary sequential decay and multifragmentation decay close to the energy threshold, i.e. 3\simeq 3 MeV/nucleon. Using the backtracing technique applied to the statistical models GEMINI and SMM we reconstruct simulated charge, mass and excitation energy distributions and compare them to the experimental ones. We show that data are better described by SMM than by GEMINI in agreement with the fact that multifragmentation is responsible for fragment production at excitation energies around 3 MeV/nucleon.Comment: 16 pages, 12 figures, 5 tables Soumis \`a Nuclear Physics

    Dexamethasone vs prednisone in induction treatment of pediatric ALL: results of the randomized trial AIEOP-BFM ALL 2000

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    Induction therapy for childhood acute lymphoblastic leukemia (ALL) traditionally includes prednisone; yet, dexamethasone may have higher antileukemic potency, leading to fewer relapses and improved survival. After a 7-day prednisone prephase, 3720 patients enrolled on trial Associazione Italiana di Ematologia e Oncologia Pediatrica and Berlin-Frankfurt-Münster (AIEOP-BFM) ALL 2000 were randomly selected to receive either dexamethasone (10 mg/m(2) per day) or prednisone (60 mg/m(2) per day) for 3 weeks plus tapering in induction. The 5-year cumulative incidence of relapse (± standard error) was 10.8 ± 0.7% in the dexamethasone and 15.6 ± 0.8% in the prednisone group (P &lt; .0001), showing the largest effect on extramedullary relapses. The benefit of dexamethasone was partially counterbalanced by a significantly higher induction-related death rate (2.5% vs 0.9%, P = .00013), resulting in 5-year event-free survival rates of 83.9 ± 0.9% for dexamethasone and 80.8 ± 0.9% for prednisone (P = .024). No difference was seen in 5-year overall survival (OS) in the total cohort (dexamethasone, 90.3 ± 0.7%; prednisone, 90.5 ± 0.7%). Retrospective analyses of predefined subgroups revealed a significant survival benefit from dexamethasone only for patients with T-cell ALL and good response to the prednisone prephase (prednisone good-response [PGR]) (dexamethasone, 91.4 ± 2.4%; prednisone, 82.6 ± 3.2%; P = .036). In patients with precursor B-cell ALL and PGR, survival after relapse was found to be significantly worse if patients were previously assigned to the dexamethasone arm. We conclude that, for patients with PGR in the large subgroup of precursor B-cell ALL, dexamethasone especially reduced the incidence of better salvageable relapses, resulting in inferior survival after relapse. This explains the lack of benefit from dexamethasone in overall survival that we observed in the total cohort except in the subset of T-cell ALL patients with PGR. This trial was registered at www.clinicaltrials.gov (BFM: NCT00430118, AIEOP: NCT00613457)

    Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes

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    Mass and charge identification of charged products detected with Silicon-CsI(Tl) telescopes of the Chimera apparatus is presented. An identification function, based on the Bethe-Bloch formula, is used to fit empirical correlation between Delta E and E ADC readings, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products prior to energy calibration.Comment: 24 pages, 7 .jpg figures, submitted to Nucl.Instr.

    Isotope correlations as a probe for freeze-out characterization: central 124Sn+64Ni, 112Sn+58Ni collisions

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    124Sn+64Ni and 112Sn+58Ni reactions at 35 AMeV incident energy were studied with the forward part of CHIMERA multi-detector. The most central collisions were selected by means of a multidimensional analysis. The characteristics of the source formed in the central collisions, as size, temperature and volume, were inspected. The measured isotopes of light fragments (3 <= Z <=8) were used to examine isotope yield ratios that provide information on the free neutron to proton densities.Comment: 4 pages, Contribution to 8th International Conference on Nucleus-Nucleus Collisions, Moscow 200

    Morphology-Controllable Synthesis of CeO2on a Pt Electrode

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    Nanoscale cerium dioxides with shape of nanoparticles, nanorods, and nanotubes were electrochemically synthesized. The morphology of CeO2was modulated by changing electrode potential and potential direction. CeO2nanorods and CeO2nanotubes were synthesized via the potentiostatic and cyclic voltammeteric methods, respectively. The morphology and structure of the obtained CeO2were characterized by field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD). A possible formation mechanism has been suggested to illuminate the relationship between the preparation condition and the morphology of CeO2

    The Renin Angiotensin System (RAS) mediates bifunctional growth regulation in melanoma and is a novel target for therapeutic intervention

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    Despite emergence of new systemic therapies, metastatic melanoma remains a challenging and often fatal form of skin cancer. The renin–angiotensin system (RAS) is a major physiological regulatory pathway controlling salt–water equilibrium, intravascular volume and blood pressure. Biological effects of the RAS are mediated by the vasoactive hormone angiotensin II (AngII) via two receptor subtypes, AT1R (encoded by AGTR1) and AT2R (encoded by AGTR2). We report decreasing expression and increasing CpG island methylation of AGTR1 in metastatic versus primary melanoma and detection in serum of methylated genomic DNA from the AGTR1 CpG island in metastatic melanoma implying that AGTR1 encodes a tumour suppressor function in melanoma. Consistent with this hypothesis, antagonism of AT1R using losartan or shRNA-mediated knockdown in melanoma cell lines expressing AGTR1 resulted in acquisition of the ability to proliferate in serum-free conditions. Conversely, ectopic expression of AGTR1 in cell lines lacking endogenous expression inhibits proliferation irrespective of the presence of AngII implying a ligand-independent suppressor function for AT1R. Treatment of melanoma cell lines expressing endogenous AT2R with either AngII or the AT2R-selective agonist Y6AII induces proliferation in serum-free conditions whereas the AT2R-specific antagonists PD123319 and EMA401 inhibit melanoma growth and angiogenesis and potentiate inhibitors of BRAF and MEK in cells with BRAF V600 mutations. Our results demonstrate that the RAS has both oncogenic and tumour suppressor functions in melanoma. Pharmacological inhibition of AT2R may provide therapeutic opportunities in melanomas expressing this receptor and AGTR1 CpG island methylation in serum may serve as a novel biomarker of metastatic melanoma
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