[Closure of persisting rectourethral fistula after suprasymphyseal adenoma enucleation of the prostate by combining the Bressel-Naujox and gracilis flap procedure]. / Verschluss einer persistierenden urethrorektalen Fistel nach suprasymphysärer Adenomenukleation der Prostata durch kombiniertes Bressel-Naujox- mit einem Gracilisflapverfahren.

When taking into consideration the basic principles of fistula surgery, numerous options are available for the surgical repair of rectourethral fistulas. However, there is no standard regarding which surgical method should be used under which circumstances-due to the heterogeneity of this disease. This case report describes the individual adaptation of a surgical technique that is used for the treatment of vesicovaginal fistulas to treat a rectourethral fistula in a patient who had already undergone an unsuccessful fistula closure attempt. Successful closure of the fistula was achieved on the basis of an established method using tissue interposition.

The dependence on ammonia pretreatment of N-O activation by Co(II) sites in zeolites: a DFT and ab initio molecular dynamics study.

This work is focused on the donor properties of cobalt-exchanged cationic sites in zeolites. It is based on cluster and periodic density functional theory modeling for relevant {[Co(II)(NH3)n]-NO} adducts, where Co(II) means a cobalt cation embedded either in a periodic model of chabasite (CHA) zeolite or in model clusters. NO stretching frequencies were derived from MD trajectories and compared to harmonic values from cluster calculations. By relating calculated NO frequencies to experimental FTIR spectra, it was shown that the forms of {Co(II)-NO} adducts comprising three or four ammonia co-ligands dominate the spectrum taken in ammonia-saturation conditions while forms with two NH3 ligands prevail under intermediate ammonia saturation. Finally, this work confirms the critical dependence of Co(II) activation ability towards NO upon the center donor properties, reinforced by ligation of strong donor ammonia ligands. However, strongly bound ligands appear also to compete with interaction of the center with the electron-rich framework, and a balance must be observed to maintain optimal activation ability. Graphical abstract A snapshot from MD trajectory showing a fragment of periodic framework with twoCo(II)-NO centers, bound to one framework oxygen and strongly coordinating three ammonia ligands with four others forming the second coordination sphere.