Tricuspid Annuloplasty: Transcatheter Approaches.

PURPOSE OF REVIEW: New transcatheter techniques to perform tricuspid annuloplasty are evolving and are introduced into the clinical routine. Yet, clinical experience is limited. RECENT FINDINGS: Currently, 3 different techniques for tricuspid annuloplasty have been used in larger clinical cohorts. They can be divided into direct annuloplasty techniques and suture plication techniques. The largest clinical evidence is related to direct annuloplasty techniques. It has been shown that annular dimensions can be effectively reduced. This translates into an improvement of the degree of tricuspid regurgitation and improvement of clinical symptoms. Due to the newness of this type of therapy, long-term data is limited, but for one of the described techniques, published data show that the positive effects persist over a 2-year period. Transcatheter approaches are safe and are able to treat tricuspid regurgitation effectively. There are still differences in the efficacy of the different techniques. Clinical experience varies among the different approaches.

Hydrogen storage by physisorption on dodecahydro-closo-dodecaboranes.

Hydrogen physisorption on dodecahydro-closo-dodecaborane units is studied using ab initio quantum chemical calculations based on Møller-Plesset perturbation theory. After adding zero-point energy corrections, the adsorption energy due to the charge-quadrupole and the charge-induced dipole interaction is somewhat larger than the more common dispersion interaction with spacer molecules in molecular framework compounds. Furthermore, the energy landscape on the surface of the near-spherical B12H12(2-) permits considerable residual dynamics with corresponding configurational entropy that releases partly the requirements on the magnitude of the adsorption energy. If it can be made fully accessible in an open architecture the system promises an enormous storage capacity. An experimental test for Cs2B12H12 dispersed in the cages of a dealuminated faujasite zeolite amends the theoretical study.