270 research outputs found

    Influence of heat input waveform on transient critical heat flux of subcooled water flow boiling in a short vertical tube

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    The transient critical heat fluxes (CHFs) of the subcooled water flow boiling for ramp-wise heat input [Q = αt, α = 6.21 × 108 to 1.63 × 1012 W/m3 s, (q 1.08 × 107 to 6.00 × 107 W/m2)] and stepwise one [Q = Qs, Qs = 0 W/m3 at t = 0 s and Qs = 2.95 × 1010 to 7.67 × 1010 W/m3 at t > 0 s, (q = 0 W/m2 at t = 0 s and q 1.61 × 107 to 3.87 × 107 W/m2 at t > 0 s)] with the flow velocities (u = 4.0–13.3 m/s), the inlet subcoolings (ΔTsub, in = 86.8–153.3 K) and the inlet pressures (Pin = 742.2–1293.4 kPa) are systematically measured by an experimental water loop comprised of a pressurizer. The SUS304 tubes of inner diameters (d = 3, 6 and 9 mm), heated lengths (L = 33.15, 59.5 and 49.3 mm), L/d (=11.05, 9.92 and 5.48), and wall thickness (δ = 0.5, 0.5 and 0.3 mm) respectively with the rough finished inner surface (surface roughness, Ra = 3.18 μm) are used in this work. The experimental errors in the subcooling measure and the pressure one are ±1 K and ±1 kPa, while in the heat flux it is ±2%. The transient CHF data for the ramp-wise heat input and the stepwise one are compared with those for the exponentially increasing heat input (Q = Q0 exp(t/τ), τ = 16.82 ms to 15.52 s) previously obtained and the dominant variables on transient CHF for heat input waveform difference are confirmed. The transient CHF data are compared with the values calculated by the steady state CHF correlations against inlet and outlet subcoolings, and the applicability of steady state CHF correlations is confirmed extending its possible validity for the reduced time, ωp, down to 800 ms. The transient CHF data are compared with the values calculated by the transient CHF correlations against inlet and outlet subcoolings, and the influence of heat input waveform on transient CHF is clarified based on the experimental data for the ramp-wise heat input, the stepwise one and the exponentially increasing one. The dominant mechanisms of the subcooled flow boiling critical heat flux for the ramp-wise heat input, the stepwise one and the exponentially increasing one are discussed

    An eccentric calpain, CAPN3/p94/calpain-3

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    AbstractCalpains are Ca2+-regulated proteolytic enzymes that are involved in a variety of biological phenomena. Calpains process substrates by limited proteolysis to modulate various protein functions in the cell, and are thus called “modulator proteases.” CAPN3, previously called p94 or calpain-3, has unique features that are not found in any of the other 14 human calpains, or even in other proteases.For instance, CAPN3 undergoes extremely rapid and exhaustive autodegradation. CAPN3 is also the first (and so far, the only) intracellular enzyme found to depend on Na+ for its activation. CAPN3 has both proteolytic and non-proteolytic functions. It has the interesting distinction of being the only protease, other than a few virus proteases, with the ability to regain protease function after its autolytic dissociation; this occurs through a process known as intermolecular complementation (iMOC). Gene mutations causing CAPN3 defects are responsible for limb-girdle muscular dystrophy type 2A (LGMD2A).Unusual characteristics of CAPN3 have fascinated researchers, but have also hampered conventional biochemical analysis. In this review, we describe significant findings about CAPN3 from its discovery to the present, and suggest promising avenues for future CAPN3 research

    Holographic Construction of Technicolor Theory

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    We construct a dual description of technicolor theory based on the D4/D8 brane configuration. A strongly-coupled technicolor theory is identified as the effective theory on D-branes, and from the gauge/gravity correspondence, we explore the weakly-coupled holographic description of dynamical electroweak symmetry breaking. It is found from the D-brane probe action that the masses of W and Z bosons are given by the decay constant of technipion, and the technimesons become hierarchically heavy. Moreover, the couplings of heavier modes to standard model fermions are rather suppressed. The oblique correction parameters are also evaluated and found to be small except for the S parameter, which can be reduced by modifying the model. The fermion fields are introduced at the intersections of D-branes and their masses are generated via massive gauge bosons from open strings stretching between D-branes.Comment: 23 pages; references added, minor change

    Role of Tumor-Associated Macrophages in Sarcomas

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    Simple Summary Recent studies have shown the pro-tumoral role of tumor-associated macrophages (TAMs) not only in major types of carcinomas but also in sarcomas. Several types of TAM-targeted drugs have been investigated under clinical trials, which may represent a novel therapeutic approach for bone and soft-tissue sarcomas. Sarcomas are complex tissues in which sarcoma cells maintain intricate interactions with their tumor microenvironment. Tumor-associated macrophages (TAMs) are a major component of tumor-infiltrating immune cells in the tumor microenvironment and have a dominant role as orchestrators of tumor-related inflammation. TAMs promote tumor growth and metastasis, stimulate angiogenesis, mediate immune suppression, and limit the antitumor activity of conventional chemotherapy and radiotherapy. Evidence suggests that the increased infiltration of TAMs and elevated expression of macrophage-related genes are associated with poor prognoses in most solid tumors, whereas evidence of this in sarcomas is limited. Based on these findings, TAM-targeted therapeutic strategies, such as inhibition of CSF-1/CSF-1R, CCL2/CCR2, and CD47/SIRP alpha, have been developed and are currently being evaluated in clinical trials. While most of the therapeutic challenges that target sarcoma cells have been unsuccessful and the prognosis of sarcomas has plateaued since the 1990s, several clinical trials of these strategies have yielded promising results and warrant further investigation to determine their translational benefit in sarcoma patients. This review summarizes the roles of TAMs in sarcomas and provides a rationale and update of TAM-targeted therapy as a novel treatment approach for sarcomas
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