The present investigation provides evidence that gastric banding remains effective after more than 10 years in less than 50 % of initially operated patients. Older (>50 years) and male patients seemed to maintain the banding as long-time carriers with good results, and these patients subjectively profited from this method. Good results can be achieved if patients are followed thoroughly, and alternative surgical options for patients who fail may be offered with longstanding success.

Ferrocene and nickelocene do not react with each other in solution; however, the large impact of the paramagnetic component on the ferrocene 1H NMR signal linewidth and relaxation times has been quantified. Co-crystallization of ferrocene and nickelocene at any ratio from a solvent can be explained with both pure substances crystallizing in the same space group P21/n. As a new phenomenon, when a ferrocene single crystal is exposed to polycrystalline nickelocene in the absence of a solvent, the nickelocene migrates into the ferrocene crystal lattice and a mixed crystal is formed that retains its macroscopic shape. This process has been proven visually by cutting the single crystal. Mixing polycrystalline ferrocene with polycrystalline nickelocene at different molar ratios with a mortar and pestle leads to crystalline solid solutions with the corresponding molar ratios of both components. This migration of one organometallic component into an existing crystal lattice of another at ambient temperature in the absence of a solvent has not been described previously. Paramagnetic 1H solid-state NMR spectroscopy of static and rotating samples of dry ferrocene/nickelocene mixtures at varying ratios is used to prove and quantify the mixing of both metallocenes at the molecular level. A single-crystal X-ray structure of a 50/50 mixed crystal corroborates the NMR results that nickelocene and ferrocene are randomly distributed in the lattice and that the space group P21/n is retained. All ferrocene molecules in the mixed crystal lattice show a broadening of their 1H wideline signals and residual magic-angle spinning (MAS) lines at ambient temperature. The broadening of the ferrocene signals correlates with the nickelocene content. 1H T 1 relaxation time measurements for the signals of ferrocene in samples with different amounts of nickelocene corroborate the assumption that the signal broadening is due to paramagnetic dipole–dipole relaxation of ferrocene molecules in the vicinity of nickelocene. Spatially separated ferrocene and nickelocene powders in one rotor show the solid-state NMR characteristics of the individual polycrystalline metallocenes. The described formation of solid solutions of metallocenes in the absence of a solvent will open new pathways to homogeneously mixed nanoparticles with desired metal ratios and dual-atom catalysts.

Zusammenfassung. Die neurodegenerative Erkrankung Achalasie (veraltet: «Kardiaspasmus») stellt nach der Refluxerkrankung die zweithäufigste funktionelle Erkrankung des Ösophagus dar. Sie ist mit einem extrem hohen Leidensdruck für die Patienten verbunden. Pathophysiologisch handelt es sich um eine Kombination aus fehlender schluckreflektorischer Relaxation am Mageneingang und gestörter Peristaltik der tubulären Speiseröhre. Goldstandard in der Diagnostik ist die hochauflösende Manometrie. Die Erkrankung ist nicht heilbar, das therapeutisch Spektrum umfasst medikamentöse, endoskopisch-interventionelle und operative Verfahren.