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  • 1
    Electronic Resource
    Electronic Resource
    High-speed multishot pellet injector prototype for the Frascati Tokamak Upgrade (1998)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 69 (1998), S. 2675-2680 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The Frascati Tokamak Upgrade (FTU) may require multiple high-speed pellet injection in order to achieve quasi-steady-state conditions. A research and development program was thus being pursued at ENEA Frascati, aimed at developing a multishot two-stage pellet injector (MPI), featuring eight "pipe gun" barrels and eight small two-stage pneumatic guns. According to FTU requirements, the final goal is to simultaneously produce up to eight D2 pellets, and then deliver them during a plasma pulse (1 s) with any time schedule, at speeds in the 1–2.5 km/s range. A prototype was constructed and tested to demonstrate the feasibility of the concept, and optimize pellet formation and firing sequences. This laboratory facility was automatically operated by means of a programmable logic controller (PLC), and had a full eight-shot capability. However, it was equipped as a first approach with only four two-stage guns. In this article we will describe in detail the guidelines of the MPI prototype design, which were strongly influenced by some external constraints. We will also report on the results of the experimental campaign, during which the feasibility of such a two-stage MPI was demonstrated. Sequences of four intact D2 pellets in the 1.2–1.6 mm size range, fired at time intervals of a few tens up to a few hundreds of ms, were routinely delivered in a laboratory experiment at injection speeds above 2.5 km/s, with good reproducibility and satisfactory aiming dispersion. Some preliminary effort to address the problem of propellant gas handling, based on an innovative approach, gave encouraging results, and work is in progress to carry out an experiment to definitely test the feasibility of this concept. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148997
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  • 2
    Electronic Resource
    Electronic Resource
    Acceleration of large size deuterium pellets to high speeds using a small two-stage pneumatic gun (1999)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 2355-2364 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The technology of two-stage pneumatic pellet injectors represents by far the most reliable way to perform deep plasma fueling, with pipe gun devices capable of routinely launching small or medium size (up to 4 mm) D2 pellets at speeds in excess of 3 km/s, using rather small two-stage guns. It is still an open question, however, if scaling of the pellet size to the International Thermonuclear Experimental Reactor relevant values (6–8 mm) will or will not require a somewhat proportional increase in the physical size of the two-stage gun. In order to investigate this question, an extensive study was carried out at ENEA Frascati, using numerical simulation codes. It clearly indicated that a "compact" two-stage gun may have the potential to accelerate large size pellets at speeds up to 5 km/s. A low cost experiment was also scheduled. A spare pipe-gun cryostat of the single-shot two-stage pneumatic injector, previously used for high-speed pellet fueling of the Frascati tokamak upgrade, was modified in order to accommodate larger bore (up to 6 mm) launching barrels. In this article, we will mainly discuss the results of numerical simulations. A very early experimental campaign, carried out in 1996, will also be briefly reported, during which intact 6 mm D2 pellets were launched at speeds up to 2.5 km/s. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1149763
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  • 3
    Electronic Resource
    Electronic Resource
    Impaired Gamma Interferon Production by Cells from Patients with Lymphoproliferative Disorders of Mature T and NK Cells (1985)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 21 (1985), S. 0 
    Details
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We investigated Interferon (IFN) production by peripheral blood mononuclear cells from four patients with chronic OKT4 T-lymphocytic leukaemia and three patients with abnormal expansions of granular lymphocytes. No spontaneous production of IFN-γ was found in supernatants of cultures from both patients and normal controls. However, whereas the enzyme galactose oxidase or staphylococcal enterotoxin B was able to induce IFN-γ production by normal cells, no production could be obtained in the cells under study. The possibility that this lack of production might have been attributed to an excess of N-acetylneuramic acid masking galactose residues or to a defect of monocyte accessory cells was ruled out either by pre-treating the cells with neuraminidase or by adding normal adherent cells to the cultures, both of which resulted in a lack of production. On the contrary, the calcium ionophore A23187 (considered to act as a second specific step, following oxidation of galactose residues, toward genetic derepression of IFN-γ) induced considerable IFN-γ production in all the three tested patients. It can be concluded that, although in rare cases, as previously reported by other authors, cells from patients with T or NK lymphoproliferative disorders may spontaneously produce IFN-γ, this is not a general mechanism that underlies the disease. In fact, in all our cases a defect of IFN-γ production was found. This defect seems due to an alteration at the membrane level of the galactose-containing glycoproteins and can be restored by induction with a calcium ionophore.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3083.1985.tb01436.x
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  • 4
    Electronic Resource
    Electronic Resource
    Predictions of pressure drop and heat transfer in concentric annular ducts with modified power law fluids (1992)
    Springer
    Heat and mass transfer 27 (1992), S. 209-215 
    Details
    ISSN: 1432-1181
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Description / Table of Contents: Zusammenfassung Die folgenden numerischen Berechnungen untersuchen für die Strömung in konzentrischen Ringkanälen den Druckverlust und die Wärmeübertragungscharakteristik von Fluiden, die mit dem modifizierten Potenz-Ansatz beschrieben werden. Die betrachtete Strömung ist stationär, voll ausgebildet und laminar. Alle Stoffwerte außer der Viskosität sind konstant. Die Randbedingungen für den Wärmeübergang sind konstante Wärmestromdichte am inneren Rohr und ein adiabates äußeres Rohr. Ergebnisse werden für das Produkt Reibungsfaktor—Reynoldszahl und für die Nusselt-Zahl als Funktion eines dimensionslosen Parameters für den Geschwindigkeitsgradienten gezeigt. Diese werden als Korrelationsgleichungen formuliert, die eine gebräuchliche Darstellung der Ergebnisse des kompletten Berechnungsgebietes ergeben: von niedrigen Geschwindigkeitsgradienten, wo die Viskosität dem Ansatz nach Newton folgt, zu den höheren Geschwindigkeitsgradienten, wo das Verhalten dem reinen Potenzansatz entspricht, und bei einem Zwischenstadium, in dem die Viskosität in einem Übergangsbereich liegh.
    Notes: Abstract The following numerical analysis examines the pressure drop and heat transfer characteristics associated with flows of modified power law fluids through concentric annular ducts. The flows considered are steady, fully developed and laminar with constant properties, except for viscosity. The boundary conditions for the heat transfer problem are constant heat flux at the inner tube, and an adiabatic outer tube. Results are presented for the friction factor-Reynolds number product and for the Nusselt number as a function of a dimensionless shear rate parameter. These are expressed as correlation equations which give a convenient description of the results throughout the complete domain of the analysis: from low shear rates where the viscosity is Newtonian, to the higher shear rates where the behavior is purely power law, and at the intermediate shear rates where the viscosity is transitional.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01589918
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  • 5
    Electronic Resource
    Electronic Resource
    Interferon production in primary immunodeficiencies (1984)
    Springer
    Journal of clinical immunology 4 (1984), S. 388-394 
    Details
    ISSN: 1573-2592
    Keywords: Immunodeficiency ; gamma-interferon ; alpha-interferon ; monoclonal antibodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Alpha- and gamma-interferon (IFN) production by peripheral blood mononuclear cells (PBMC) from 18 patients affected by primary immunodeficiency syndromes was examined and compared with that of 20 normal donors. Patients included 8 with common variable immunodeficiency (CVI), 2 with congenital agammaglobulinemia, 4 with ataxia-telangiectasia, 2 with hyper-IgE syndrome, 1 with chronic EBV infection, 1 with combined immunodeficiency, and 1 with immunodeficiency with hyper-IgM. No spontaneous IFN production was observed in either patients and controls. Newcastle disease virus-induced alpha-IFN production was found to be normal in all patients. Gamma-IFN was induced by both galactose oxidase and staphylococcal enterotoxin (B). Gamma-interferon production was low or undetectable in patients with ataxia-telangiectasia, in immunodeficiency with hyper-IgM, and in hyper-IgE syndrome. No major defect of gamma-IFN was found in other types of immunodeficiency, despite the presence of occasional low producers (1 of 8 CVI patients and 1 case of congenital agammaglobulinemia). No correlation was found between IFN production and natural killer activity in individual patients. The analysis of lymphocyte subsets by monoclonal antibodies revealed gross imbalances of helper/inducer and suppressor/cytotoxic subpopulations, but no overall correlation could be established with gamma-IFN production. The observation of major defects in gamma-IFN yield only in diseases with depression of T cell-mediated immunity might contribute to a better understanding of the pathogenetical mechanisms in these diseases. Moreover, future studies should monitor thesein vitro functions and their modifications byin vitro orin vivo manipulations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00917142
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  • 6
    Electronic Resource
    Electronic Resource
    CD 4-positive lymphoid cells rescue HIV-1 replication from abortively infected human primary endothelial cells (1993)
    Springer
    Archives of virology 132 (1993), S. 267-280 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Human primary endothelial cell cultures, derived from umbilical vein (HUVEC), can be infected by different strains of HIV-1, but mature virus production remains undetectable both in supernatants and in cellular extracts. Yet viral DNA is transiently detectable during the first days of infection, but progressively declines during the subsequent days. This finding is characteristic of abortive infections. Co-culture of HUVEC carrying HIV DNA with activated peripheral blood mononuclear cells or with CD 4-positive lymphoid cells elicited a massive cpe (syncytia formation and cell degeneration) in the latter cells, caused by the establishment of productive HIV-1 infection. HUVEC infected in the presence of AZT were significantly impaired in the ability to transmit the infection of CD 4-positive cells, indicating that active DNA synthesis is required in HUVEC before rescue by CD 4-positive cells. These results are of interest in view of the possibility that endothelial cells can play a role in the transmission of HIV-1 infection from infected pregnant women to the foetuses, and, more generally, suggest a potential role of endothelial cells as a transient reservoir of HIV-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01309538
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  • 7
    Electronic Resource
    Electronic Resource
    Replication of human immunodeficiency virus: yield of infectious virus under single growth cycle conditions (1988)
    Springer
    Archives of virology 103 (1988), S. 127-131 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Replication kinetics of HIV was studied under single growth cycle conditions by backtitrating infectious virus released or remained cell-associated at each time point. Under these conditions HIV seems to replicate faster than previously estimated. The amount of cell-associated virus always exceeds the one detectable in the medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01319814
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  • 8
    Electronic Resource
    Electronic Resource
    Differences in the mechanism of induction of interferon-alpha by Herpes simplex virus and Herpes simplex virus-infected cells (1988)
    Springer
    Archives of virology 103 (1988), S. 219-229 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cellular source of IFN alpha after induction with Herpes simplex virus type-1 (HSV) and HSV-infected fibroblasts was investigated by using human peripheral blood mononuclear cell (PBMC) populations, purified according to conventional procedures, and which included T- and B-lymphocytes as well as monocytes. It appears that the cells responding to HSV virions are monocytes, whereas the PBMC population induced by HSV-infected cells is represented by B-lymphocytes. Furthermore, by using monoclonal antibody (MoAb) to HLA class I and class II products, it appears that different membrane structures are involved in the induction of IFN by HSV virions, as opposed to HSV-infected cells. In fact, most anti-HLA class II MoAbs inhibit IFN induction by HSV-infected cells, and not IFN induction by HSV virions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01311094
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  • 9
    Electronic Resource
    Electronic Resource
    Antibody to ICAM-1 mediates enhancement of HIV-1 infection of human endothelial cells (1995)
    Springer
    Archives of virology 140 (1995), S. 951-958 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Human umbilical vein endothelial cells (HUVEC) can be abortively infected with HIV-1, but virus production is rescued by the addition of T cells. Monoclonal antibody (Mab) to ICAM-1, but not its Fab' fragment or MAbs to LFA-1 and PECAM-1, increases HIV-1 infection of HUVEC by enhancing HIV-1 absorption. Enhancement by anti ICAM-1 is probably due to a bridging effect different from the ADE mediated by anti-gp120 that involves FcR or CR-mediated capture of the virus-antibody complex. Since antibodies to cell membrane molecules are present in HIV-1 infected patients, the ADE mediated by such a mechanism can be important in AIDS pathogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01314971
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  • 10
    Electronic Resource
    Electronic Resource
    Host cell antigenic profile acquired by HIV-1 is a marker of its cellular origin (1995)
    Springer
    Archives of virology 140 (1995), S. 1849-1854 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary HIV-1 acquires cell membrane proteins during budding. The cell membrane proteins (CMP) profile of laboratory HIV-1 strains grown in different host cells was established, by using an immobilized antibody capture (IAC), to verify whether CMPs present on HIV-1 correlate with its host cell origin. HIV-1 grown in different cell lines incorporates cell markers such as CD3, CD19, CD14, CD31 and IL 2-R, according to the distinctive expression of these antigens on the host cells. Furthermore, also T-tropic and monocytotropic HIV-1 strains display host cell specific markers, supporting the hypothesis that virus associated CMPs are a marker of host cell origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01384347
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