Phase transition and thermodynamical geometry for Schwarzschild AdS black hole in AdS5 × S5 spacetime

We study thermodynamics and thermodynamic geometry of a five-dimensional Schwarzschild AdS black hole in $AdS_5\times{S^5}$ spacetime by treating the cosmological constant as the number of colors in the boundary gauge theory and its conjugate quantity as the associated chemical potential. It is found that the chemical potential is always negative in the stable branch of black hole thermodynamics and it has a chance to be positive, but appears in the unstable branch. We calculate scalar curvatures of the thermodynamical Weinhold metric, Ruppeiner metric and Quevedo metric, respectively and we find that the divergence of scalar curvature is related to the divergence of specific heat with fixed chemical potential in the Weinhold metric and Ruppeiner metric, while in the Quevedo metric the divergence of scalar curvature is related to the divergence of specific heat with fixed number of colors and the vanishing of the specific heat with fixed chemical potential.Comment: 19pages,9figure

Functional examination of novel kisspeptin phosphinic peptides

Kisspeptins acting on their cognate G protein-coupled receptor, kisspeptin receptor, play important roles in the suppression of cancer cell metastasis and regulation of the reproductive system, and therefore are important for therapeutic intervention. All native functional human kisspeptins (kisspeptin-54, kisspsptin-14 and kisspeptin-13) share the 10 amino acids of kisspeptin-10 at their C-terminus (45–54). However, they are inactivated rapidly by matrix metalloproteinases (MMPs) through the cleavage of the peptide bond between glycine51 and leucine52, which limits their clinical applications. Development of MMP-resistant analogues of kisspeptins may provide better therapeutic outputs. In the present study, two kisspeptin phosphinic peptides were designed and synthesized, and their ability to induce phosphorylation of ERK1/2 through kisspeptin receptor and their inhibition on MMP-2 and MMP-9 whose activity correlates with cancer metastasis were assessed. The results showed that one analogue, phosphinic kisspeptin R isomer (PKPR), exhibited kisspeptin receptor-agonistic activity and also inhibitory activity on MMP-2, indicating that PKPR may serve as a lead for the further development of kisspeptin analogues for therapeutic purpose

CO2 adsorption and separation properties of M-MOF-74 materials determined by molecular simulation

This study simulated the adsorption and separation of CO2 by the metal-organic frameworks material M-MOF-74, established the skeleton model of M-MOF-74 series adsorbent, and calculated the adsorption of CO2 pure component gas and CO2/N2 mixed gas on MMOF- 74 series adsorbent by the grand canonical Monte Carlo method. Among the CO2 adsorption performances of MOF-74 materials with metal centers of Mg, Co, Ni, and Zn, Mg-MOF-74 had the highest CO2 adsorption capacity, adsorption selection coefficient and adsorption heat. When mixed gas was adsorbed, the law of CO2 adsorption was consistent with that of pure CO2 adsorption. The size law of adsorption heat on MOF-74 was similar to that of adsorption amount. Our findings demonstrated that the interaction between the metal-organic framework material and CO2 is greater than that between the material and N2. The interaction between the gas and the MOF-74 series adsorbent was the main factor affecting the adsorption amount, which reveals the strong influence of metal central atoms on the amount of gas adsorption. Our findings provide new ideas for the design of efficient adsorbent materials.Cited as: Deng, J., Zhao, G., Zhang, L., Ma, H., Rong, Y. CO2 adsorption and separation properties of M-MOF-74 materials determined by molecular simulation. Capillarity, 2023, 6(1): 13-18. https://doi.org/10.46690/capi.2023.01.0