For the purpose of simulating the surface alteration process called "space weathering", experiments of pulse laser irradiation, proton implantation, and laser irradiation to proton implanted samples were performed and reflectance spectra of altered materials were measured. To simulate the impact heating by micrometeorite bombardments, we made a new apparatus using a pulse laser whose pulse duration is 6-8 nanoseconds, comparable with a timescale of micrometeorite impacts. We find that the degree of space weathering, i.e., change of reflectance spectrum should depend on mineral composition. Laser irradiation onto olivine produces the largest reduction of albedo and the highest reddening of reflectance spectrum. In general, variation of olivine spectra is much larger than that of pyroxenes. Depths of absorption bands do not change in the scaled spectra. The olivine spectrum after the laser irradiation can match spectra of some olivine asteroids within a subtype of S-type asteroids. Comparison of Vesta spectrum with altered pyroxene spectra suggests that Vesta surface would be relatively older than olivine asteroids. We also investigate the influence of solar wind proton and pyroxene FeO content. The proton implantation causes small changes in olivine and enstatite spectra. Implanted protons do not influence spectral change by the laser irradiation: the laser irradiation and the proton implantation do not produce multiplicative but additive changes on the reflectance spectra. FeO content of pyroxenes does not relate to the degree of reflectance change.

Background and Aim Sarcopenia is a prognostic factor in hepatocellular carcinoma (HCC) patients. HCC patients who underwent transcatheter arterial chemoembolization (TACE) are at a risk of muscle atrophy. We aimed to investigate the effects of in‐hospital exercise on muscle mass and factors associated with muscle hypertrophy in HCC patients who underwent TACE. Methods We enrolled 209 HCC patients who underwent TACE. Patients were classified into either an exercise (n = 102) or control (n = 107) group. In the exercise group, patients were treated with in‐hospital exercise (median 2.5 metabolic equivalents/20–40 min/day). The effects of exercise on muscle mass were evaluated by changes in skeletal muscle index (ΔSMI) between before and after TACE. Factors associated with an increase in SMI were analyzed by logistic regression and decision‐tree analyses. Results There was no significant difference in serum albumin and bilirubin levels between the two groups. ΔSMI was significantly higher in the exercise group than in the control group (0.28 cm2/m2 vs −1.11 cm2/m2, P = 0.0029). In the logistic regression analysis, exercise was an independent factor for an increase in SMI (hazard ratio 2.13; 95% confidence interval 1.215–3.846; P = 0.0085). Moreover, the decision‐tree analysis showed that exercise was the initial divergence variable for an increase in SMI (the ratio of increased SMI: 53% in the exercise group vs 36% in the control group). Conclusions In‐hospital exercises increased muscle mass in HCC patients who underwent TACE. In addition, exercise was an independent factor for muscle hypertrophy. Thus, in‐hospital exercise may prevent sarcopenia in HCC patients who underwent TACE.

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