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1.
Rev Sci Instrum ; 91(2): 023510, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-32113382

ABSTRACT

The requirements of ITER neutral beam injectors (1 MeV, 40 A negative deuterium ion current for 1 h) have never been simultaneously attained; therefore, a dedicated Neutral Beam Test Facility (NBTF) was set up at Consorzio RFX (Padova, Italy). The NBTF includes two experiments: SPIDER (Source for the Production of Ions of Deuterium Extracted from Rf plasma), the full-scale prototype of the source of ITER injectors, with a 100 keV accelerator, to investigate and optimize the properties of the ion source; and MITICA, the full-scale prototype of the entire injector, devoted to the issues related to the accelerator, including voltage holding at low gas pressure. The present paper gives an account of the status of the procurements, of the timeline, and of the voltage holding tests and experiments for MITICA. As for SPIDER, the first year of operation is described, regarding the solution of some issues connected with the radiofrequency power, the source operation, and the characterization of the first negative ion beam.

2.
Rev Sci Instrum ; 87(2): 02B325, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26932053

ABSTRACT

A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF6 instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

3.
Gene Ther ; 22(6): 449-57, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25789461

ABSTRACT

Mesenchymal stromal cells (MSCs) are cardioprotective in acute myocardial infarction (AMI). Besides, we have shown that intramyocardial injection of plasmid-VEGF(165) (pVEGF) in ovine AMI reduces infarct size and improves left ventricular (LV) function. We thus hypothesized that MSCs overexpressing VEGF(165) (MSCs-pVEGF) would afford greater cardioprotection than non-modified MSCs or pVEGF alone. Sheep underwent an anteroapical AMI and, 1 week later, received intramyocardial MSCs-pVEGF in the infarct border. One month post treatment, infarct size (magnetic resonance) decreased by 31% vs pre-treatment. Of note, myocardial salvage occurred predominantly at the subendocardium, the myocardial region displaying the largest contribution to systolic performance. Consistently, LV ejection fraction recovered to almost its baseline value because of marked decrease in end-systolic volume. None of these effects were observed in sheep receiving non-transfected MSCs or pVEGF. Although myocardial retention of MSCs decreased steeply over time, the treatment induced significant capillary and arteriolar proliferation, which reduced subendocardial fibrosis. We conclude that in ovine AMI, allogeneic VEGF-overexpressing MSCs induce subendocardial myocardium salvage through microvascular proliferation, reducing infarct size and improving LV function more than non-transfected MSCs or the naked plasmid. Importantly, the use of a plasmid rather than a virus allows for repeated treatments, likely needed in ischemic heart disease.


Subject(s)
Mesenchymal Stem Cells/metabolism , Myocardial Infarction/metabolism , Vascular Endothelial Growth Factor A/metabolism , Animals , Cell Line , Humans , Magnetic Resonance Spectroscopy/methods , Male , Myocardial Infarction/physiopathology , Myocardium/pathology , Plasmids/metabolism , Sheep , Ventricular Function, Left
4.
J Mol Spectrosc ; 182(2): 378-84, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9398551

ABSTRACT

The infrared spectrum of vinyl fluoride (CH2=CHF) has been investigated in the region 390-590 cm-1 at room temperature and at a resolution of 0.0016 cm-1 using a Fourier transform spectrometer. The rovibrational analysis of the spectral features allowed us to assign about 11 000 lines (J

6.
Phys Rev A Gen Phys ; 33(6): 3900-3912, 1986 Jun.
Article in English | MEDLINE | ID: mdl-9897134
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