Reinvestigating the Gamow Factor of Reactions on Light Nuclei

We present a modified Gamow factor by reinvestigating the conventional assumptions used in its derivation. The conventional Gamow factor, factorized from the total cross section, effectively describes the penetration probabilities (PPs) in low-energy nuclear reactions under the assumption of particle energies significantly lower than the Coulomb barrier. However, we find that the assumption is invalid for light nuclei, resulting in PPs that depend on the nuclear potential depth for such nuclei. By adopting a potential depth fitted to experimental fusion cross sections, we demonstrate that PPs for light nuclei (D+D, D+T, D+ ^3 He, p+D, p+ ^6 Li, and p+ ^7 Li) become higher than those predicted by the conventional form near the Coulomb barrier. This reduces the Gamow peak energy by a factor of 5.3 maximally compared to the conventional form. Furthermore, we show that the enhancement factor due to the Debye screening effects in the solar core can be reduced by approximately 5%–10% due to the modified PP. Our findings hold implications for evaluating the available energy region in low-energy reaction experiments based on the Gamow peak energy region and for understanding electron screening effects in typical astrophysical environments

Tannylated Calcium Carbonate Materials with Antacid, Anti-Inflammatory, and Antioxidant Effects

Calcium carbonate (CaCO3)-based materials have received notable attention for biomedical applications owing to their safety and beneficial characteristics, such as pH sensitivity, carbon dioxide (CO2) gas generation, and antacid properties. Herein, to additionally incorporate antioxidant and anti-inflammatory functions, we prepared tannylated CaCO3 (TA-CaCO3) materials using a simple reaction between tannic acid (TA), calcium (Ca2+), and carbonate (CO32−) ions. TA-CaCO3 synthesized at a molar ratio of 1:75 (TA:calcium chloride (CaCl2)/sodium carbonate (Na2CO3)) showed 3–6 μm particles, comprising small nanoparticles in a size range of 17–41 nm. The TA-CaCO3 materials could efficiently neutralize the acid solution and scavenge free radicals. In addition, these materials could significantly reduce the mRNA levels of pro-inflammatory factors and intracellular reactive oxygen species, and protect chondrocytes from toxic hydrogen peroxide conditions. Thus, in addition to their antacid property, the prepared TA-CaCO3 materials exert excellent antioxidant and anti-inflammatory effects through the introduction of TA molecules. Therefore, TA-CaCO3 materials can potentially be used to treat inflammatory cells or diseases