Numerical simulations of quasi-static magnetoconvection with a vertical magnetic field are carried out up to a Chandrasekhar number of Q = 10 8 over a broad range of Rayleigh numbers Ra. Three magnetoconvection regimes are identified: two of the regimes are magnetically-constrained in the sense that a leading-order balance exists between the Lorentz and buoyancy forces, whereas the third regime is characterized by unbalanced dynamics that is similar to non-magnetic convection. Each regime is distinguished by flow morphology, momentum and heat equation balances, and heat transport behavior. One of the magnetically-constrained regimes is believed to represent an 'ultimate' magnetoconvection regime in the dual limit of asymptotically-large buoyancy forcing and magnetic field strength; this regime is characterized by an interconnected network of anisotropic, spatially-localized fluid columns aligned with the direction of the imposed magnetic field that remain quasi-laminar despite having large flow speeds. As for nonmagnetic convection, heat transport is controlled primarily by the thermal boundary layer. The heat transport and dynamics in the magnetically-constrained, high-Q regimes appear to be independent of the thermal Prandtl number.

Despite the potential efficacy of immune checkpoint blockade for effective treatment of cancer, this therapeutic modality is not generally curative, and only a fraction of patients respond. Combination approaches provide strategies to target multiple antitumor immune pathways to induce synergistic antitumor immunity. Here, a multi-combination immunotherapy, including photothermal therapy (PTT), indoleamine-2,3-dioxygenase (IDO) inhibition, and programmed cell death-ligand 1 (PD-L1) blockade, is introduced for inducing synergistic antitumor immunity. We designed a multifunctional IDO inhibitor (IDOi)-loaded reduced graphene oxide (rGO)-based nanosheets (IDOi/rGO nanosheets) with the properties to directly kill tumor cells under laser irradiation and in situ trigger antitumor immune response. In vivo experiments further revealed that the triggered immune response can be synergistically promoted by IDO inhibition and PD-L1 blockade; the responses included the enhancement of tumor-infiltrating lymphocytes, including CD45 + leukocytes, CD4 + T cells, CD8 + T cells, and NK cells; the inhibition of the immune suppression activity of regulator T cells (T regs ); and the production of INF-γ. We also demonstrate that the three combinations of PTT, IDO inhibition, and PD-L1 blockade can effectively inhibit the growth of both irradiated tumors and tumors in distant sites without PTT treatment. This work can be thought of as an important proof of concept to target multiple antitumor immune pathways to induce synergistic antitumor immunity.

One‐dimensional resistive MHD and hybrid simulations are carried out to study the manner by which variations of the interplanetary magnetic field (IMF) direction generate dynamic pressure pulses in the magnetosheath. The reaction of the magnetosheath to the temporal IMF variation is modeled as the interaction between the bow shock (BS) and an interplanetary rotational discontinuity (RD), an Alfven wave pulse (AW), or an Alfven wave train. The resistive MHD simulation indicates that the arrival of an RD produces two time‐dependent intermediate shocks (TDISs) and two slow shocks downstream of the bow shock, which propagate through the magnetosheath toward the Earth's magnetopause. An enhancement of plasma density is present throughout the TDISs and slow shocks. A plasma dynamic pressure pulse is formed in this region. In the hybrid simulation, the two TDISs are replaced by rotational discontinuities. For a bow shock with a shock normal angle θBn > 45°, the pulse in the dynamic pressure ρV2 causes the total pressure (P + B2/2μ0 + ρV2) in the magnetosheath to increases by about 0–100% of the background value. The strength of the pressure pulse increases with the field rotation angle across the incident rotational discontinuity, while it decreases with the Mach number or upstream plasma beta of the bow shock. The pressure pulse propagates toward the magnetopause with nearly a constant amplitude. On the other hand, the BS/AW interaction leads to the generation of Alfven waves downstream of the bow shock, and large‐amplitude dynamic pressure pulses are generated in the downstream Alfven wave. Pressure pulses impinging on the magnetopause may produce magnetic impulse events (MIEs) observed in the high‐latitude ionosphere.

The steady state fast magnetic reconnection process with small separatrix angles proposed by Pestchek (1964) and generalized by Priest and Forbes (1986) is studied by a two-dimensional incompressible magnetohydrodynamic (MHD) code. In the code a undorm tangential magnetic field and normal plasma speed are specified on the inflow boundary. On the outflow boundary the tangential flow speed and tangential magnetic field are specified to be those in the Priest-Forbes' model in order to obtain different reconnection regimes. In our simulations both a undorm and a nonuniform resistivity are used. For a nonuniform resistivity model in which the resistivity in the outflow region is highly reduced, our simulations are in many aspects consistent with those in the analytical results. A steady state magnetic reconnection configuration with small separatrix angle is obtained. The plasma is heated and accelerated by the current sheets associated with slow shocks. We also obtain various regimes predicted by Priest and Forbes for different boundary conditions on the outflow boundary which are characterized by a parameter b0. They are a weak fast-mode expansion (b0=0), slow-mode compression (b0 < 0), slow-mode expansion (b0 >_ 0), and a hybrid regime of fast-mode and slow-mode expansion (0 < b0 < 1). The width and length of the current sheet for different parameters obtained in the simulations are found to be consistent with theoretical values. When the magnetic Reynolds number or the reconnection rate given on the inflow boundary increases, the diffusion region becomes smaller. However, for cases with a uniform resistivity imposed in the simulation domain it is found that the diffusion region tends to lengthen indefinitely and no steady state configuration is obtained. Magnetic islands are usually formed at the later stage of the simulation.

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