Mixed dysprosium-lanthanide nitride clusterfullerenes DyM2N@C80-Ih and Dy2MN@C80-Ih (M = Gd, Er, Tm, and Lu): synthesis, molecular structure, and quantum motion of the endohedral nitrogen atom.

Systematic exploration of the synthesis of mixed-metal Dy-M nitride clusterfullerenes (NCFs, M = Gd, Er, Tm, Lu) is performed, and the impact of the second metal on the relative yield is evaluated. We demonstrate that the ionic radius of the metal appears to be the main factor allowing explanation of the relative yields in Dy-M mixed-metal systems with M = Sc, Lu, Er, and Gd. At the same time, Dy-Tm NCFs show anomalously low yields, which is not consistent with the relatively small ionic radius of Tm3+ but can be explained by the high third ionization potential of Tm. Complete separation of Dy-Gd and Dy-Er, as well as partial separation of Dy-Lu M3N@C80 nitride clusterfullerenes, is accomplished by recycling HPLC. The molecular structures of DyGd2N@C80 and DyEr2N@C80 are analyzed by means of single-crystal X-ray diffraction. A remarkable ordering of mixed-metal nitride clusters is found despite similar size and electronic properties of the metals. Possible pyramidalization of the nitride clusters in these and other nitride clusterfullerenes is critically analyzed with the help of DFT calculations and reconstruction of the nitrogen inversion barrier in M3N@C80 molecules is performed. Although a double-well potential with a pyramidal cluster structure is found to be common for most of them, the small size of the inversion barrier often leads to an apparent planar structure of the cluster. This situation is found for those M3N@C80 molecules in which the energy of the lowest vibrational level exceeds that of the inversion barrier, including Dy3N@C80 and DyEr2N@C80. The genuine pyramidal structure can be observed by X-ray diffraction only when the lowest vibrational level is below the inversion barrier, such as those found in Gd3N@C80 and DyGd2N@C80. The quantum nature of molecular vibrations becomes especially apparent when the size of the inversion barrier is comparable to the energy of the lowest vibrational levels.

[Orthotopic bone implants for bone regeneration]. / Organotipichnye kostnye implantaty - perspektiva razvitiia sovremennykh osteoplasticheskikh materialov.

Biotechnology industry is rapidly developing. The elaboration of new biomaterials for bone reconstruction is one of the most perspective directions in tissue engineering. There are millions of surgical operations associated with use of bone graft materials every year. In this article we tried to analyze and systematize data about advanced technologies and modern trends in the preparation of bio-composite bone graft materials. Special attention is given to 3D-prototyping that allows making bone implants with individual form. Introduction of molecular biology technologies such as activating specific cytokines and growth factors at the right time makes it possible to optimize bone regeneration process. The article has also some suggestions on further improvement of the bone engineering technology.

[Low-invasive colposuspension in stress enuresis in females]. / Maloinvazivnaia kol'posuspenziia pri stressovom nederganii mochi y zhenshchin.

Retropubic colposuspension (RC) is one of leading surgical treatments of stress enuresis in women. A low-traumatic method of RC with application of special surgical instruments is proposed. Retropubic urethrocervicopexy and low-invasive colposuspension were made in 27 and 17 women, respectively. 25 women have undergone endoscopic operations. Postoperative complications were minimal in endoscopic and low-invasive interventions. Long-term results were similar to literature data. Low-invasive colposuspension is an effective and low-traumatic treatment of stress enuresis in women.

[Sacral anesthesia in transurethral resection of the prostate]. / Sakral'naia anesteziia pri transuretral'noi rezektsii predstatel'noi zhelezy.

Block anesthesia has some advantages in transurethral surgery over general anesthesia. 48 patients were operated under sacral anesthesia and 47 patients under peridural anesthesia. Anesthesia-induced complications were compared to those published in the literature. It was found that in transurethral prostatic resection sacral anesthesia is more simple and cost-effective than peridural anesthesia.