Decaying shock studies of phase transitions in MgOSiO2 systems: implications for the Super-Earths interiors

We report an experimental study of the phase diagrams of periclase (MgO), enstatite (MgSiO3) and forsterite (Mg2SiO4) at high pressures. We investigated with laser driven decaying shocks the pressure/temperature curves of MgO, MgSiO3 and Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa and 0.2-0.85 TPa respectively. A melting signature has been observed in MgO at 0.47 TPa and 9860 K, while no phase changes were observed neither in MgSiO3 nor in Mg2SiO4. An increasing of reflectivity of MgO, MgSiO3 and Mg2SiO4 liquids have been detected at 0.55 TPa -12 760 K, 0.15 TPa - 7540 K, 0.2 TPa - 5800 K, respectively. In contrast to SiO2, melting and metallization of these compounds do not coincide implying the presence of poor electrically conducting liquids close to the melting lines. This has important implications for the generation of dynamos in Super-earths mantles

Time evolution and asymmetry of a laser produced blast wave

Studies of a blast wave produced from carbon rods and plastic spheres in an argon background gas have been conducted using the Vulcan laser at the Rutherford Appleton Laboratory. A laser of 1500 J was focused onto these targets, and rear-side observations of an emission front were recorded using a fast-framing camera. The emission front is asymmetrical in shape and tends to a more symmetrical shape as it progresses due to the production of a second shock wave later in time, which pushes out the front of the blast wave. Plastic spheres produce faster blast waves, and the breakthrough of the second shock is visible before the shock stalls. The results are presented to demonstrate this trend, and similar evolution dynamics of experimental and simulation data from the FLASH radiation-hydrodynamics code are observed

Weekly platinum chemotherapy for recurrent ovarian cancer

British Journal of Cancer (2002) 86, 2–4. DOI: 10.1038/sj/bjc/6600062 www.bjcancer.co

Direct Observation of Shock-Induced Disordering of Enstatite Below the Melting Temperature

We report in situ structural measurements of shock-compressed single crystal orthoenstatite up to 337 ± 55 GPa on the Hugoniot, obtained by coupling ultrafast X-ray diffraction to laser-driven shock compression. Shock compression induces a disordering of the crystalline structure evidenced by the appearance of a diffuse X-ray diffraction signal at nanosecond timescales at 80 ± 13 GPa on the Hugoniot, well below the equilibrium melting pressure (>170 GPa). The formation of bridgmanite and post-perovskite have been indirectly reported in microsecond-scale plate-impact experiments. Therefore, we interpret the high-pressure disordered state we observed at nanosecond scale as an intermediate structure from which bridgmanite and post-perovskite crystallize at longer timescales. This evidence of a disordered structure of MgSiO3 on the Hugoniot indicates that the degree of polymerization of silicates is a key parameter to constrain the actual thermodynamics of shocks in natural environments. © 2020. The Authors

Kinase/phosphatase overexpression reveals pathways regulating hippocampal neuron morphology

Kinases and phosphatases that regulate neurite number versus branching versus extension are weakly correlated.The kinase family that most strongly enhances neurite growth is a family of non-protein kinases; sugar kinases related to NADK.Pathway analysis revealed that genes in several cancer pathways were highly active in enhancing neurite growth