The functional realization of proteins and other biological macromolecules depends on conformational dynamics and allosteric regulation, and elucidating their molecular mechanisms is an important foundation for understanding life processes. Molecular dynamics simulations are a powerful tool for investigating conformational evolution at the atomic level. However, traditional methods are limited by simulation timescales and high free-energy barriers, making it difficult to effectively capture rare conformations and their transition pathways. As a result, the development of enhanced sampling techniques has become key to overcoming this bottleneck. As a classical enhanced sampling technique, metadynamics suffers from several shortcomings, including strong dependence on collective variables and significant errors caused by bias potential accumulation. This article reviews three major improvement strategies. The first combines stochastic resetting with metadynamics, using trajectory-resetting mechanisms to improve sampling efficiency while avoiding the difficulty of optimizing collective variables. The second, SinkMeta, employs a “sinking” bias effect to enable efficient exploration of specific regions and paths. The third, OPES-based hybrid methods, improve the stability of free-energy estimation by optimizing the target distribution or the way the bias is constructed. These methods provide new ideas for characterizing free-energy landscapes and studying conformational transitions in complex biological systems, while also promoting the continued development of enhanced sampling methodologies.

Objective To explore link of change of plasma C-reactive protein (CRP) and atrial fibrillation (AF). Method The hsCRP enzyme-linked immunosorbent assay (ELISA) methods were used to measure plasma CRP levels in 21 patients with lone paroxysmal AF (LPAF) during AF and 7 days after return to sinus rhythm ;28 patients with lone sustained atrial fibrillation(LSAF) and 27 patients with rheumatic heart disease and chronic AF(RHD).Levels of plasma CRP were compared to levels in 32 patients with paroxysmal supraventricular tachycardia(PSVT) and 20 voluntary healthy subjects. Results Patients with LPAF,LPAF and RHD had high levels of CRP when compared with PSVT and the healthy subjects.No significant changes of CRP levels were found between the onset AF patients and those after 7 days of recovery.Patients with lone persistent AF and rheumatic heart disease with persistent AF had higher levels of CRP than those with LPAF,but have no significance.There were positive correlation between the duration of AF and the levels of CRP.But there were no relation with left atrial size on echocardiography,sex and ages. Conclusion These results indicate that elevated CRP levels in AF patients may play an important role in the occurrence and sustainment of AF.