Efficient parameterisation of non-collinear energy landscapes in itinerant magnets.

Magnetic exchange interactions determine the magnetic groundstate, as well as magnetic excitations of materials and are thus essential to the emerging and fast evolving fields of spintronics and magnonics. The magnetic force theorem has been used extensively for studying magnetic exchange interactions. However, short-ranged interactions in itinerant magnetic systems are poorly described by this method and numerous strategies have been developed over the years to overcome this deficiency. The present study supplies a fully self-consistent method for systematic investigations of exchange interactions beyond the standard Heisenberg model. In order to better describe finite deviations from the magnetic ground state, an extended Heisenberg model, including multi-spin interactions, is suggested. Using cross-validation analysis, we show that this extended Heisenberg model gives a superior description for non-collinear magnetic configurations. This parameterisation method allows us to describe many different itinerant magnetic systems and can be useful for high-throughput calculations.

Many-body interactions in the Al-Cu system.

The article contains computational data of many-body interactions in Al-Cu alloys, obtained using PAW-VASP calculations. Pairwise, three-site, and four-site interactions are presented. Mentioned data are relevant to the research article "Many-body mechanism of Guinier-Preston zones stabilization in Al-Cu alloys" (Gorbatov et al., 2017) [1].

[Prognosis of outcome of radical surgery in patients with lung cancer associated with severe complications and concurrent diseases]. / Prognozirovanie iskhodov radikal'nykh operatsii u bol'nykh rakom lëgkogo s tiazhëlymi sochetannymi i konkuriruiushchimi zabolevaniiami.

From 1981 to 2001 (20 years) 1307 patients with lung cancer underwent surgery. Postoperative lethality was 1.7% (after 635 pneumonectomies it was 2.4%, after 672 lob- and bilobectomies--1.2%). Medical histories of 171 operated patients with severe concomitant diseases was studied to analyze surgical outcomes depending on such important factors as age, concomitant diseases, surgical trauma. It is demonstrated that age of patients is not a factor of postoperative prognosis, but concomitant diseases and surgical trauma (i.e. pneumonectomy) are important factors of it. Results of surgery in the group of patients with four and more concomitant diseases after pneumonectomy were most unfavorable (lethality was 22.9%). In less severe surgical trauma (lobectomy) results of surgery were more favorable. It is concluded that surgery in patients with a lot of concomitant diseases must be less radical to obtain lower lethality. Radicality of treatment in these patients is ensured due to complex chemo- and radiation therapy after surgery.

[The characteristics of the spatial organization of the human EEG in ketamine-altered consciousness]. / Osobennosti prostranstvennoi organizatsii EEG cheloveka pri izmenennom ketaminom soznanii.

Spatial organization of human EEG was studied by means of topographic mapping methods with the multiparametric data estimations in the state altered by ketamine in terms of the concept of coherent structures of brain electrical activity. Two main features of the altered state of consciousness were reflected in the opposite shifts: an increase in the spatial synchronization in the left hemisphere (especially, in the posterior area) and its decrease in the left frontal and right temporal one. The obtained data are discussed from the viewpoint of dissociative effects of ketamine at the neurochemical and neurophysiological levels.

[Effect of fragmin, a low-molecular heparin, on hemostasis in patients with alimentary-constitutional obesity]. / Vliianie nizkomolekuliarnogo geparina fragmina na gemostaz u bol'nykh alimentarno-konstitutsional'nym ozhireniem.

The authors conducted comparative study of the hemostasis indices before and in the immediate period after operation for formation of a small stomach in 31 patients with stage III-IV alimentary-constitutional obesity, in 50 patients without obesity who underwent operation on the stomach, and in 15 volunteers. Nonspecific prevention of thrombogenesis was performed in all patients with normal weight and those with obesity. Patients with obesity were given in addition specific thrombogenesis prevention with nonfractionated heparin (group I) and fractionated low-molecular heparin-fragmin produced by KABI (groups II and III). Study of the parameters of the hemostasis system in the postoperative period showed nonspecific prevention of thrombogenesis to be sufficient to reduce the risk of pulmonary artery phlebothrombosis and embolism in most patients without obesity. In patients with obesity the probability of phlebothrombosis and thromboembolism is much higher, in view of which they must be given heparin in addition to nonspecific prevention. Fragmin, as an agent for thrombosis prevention, has certain advantages over nonfractionated heparin and should be used more frequently in clinical practice in patients of the risk group, e. g. with pathological obesity, in a dose no less than 100 U/kg. With the use of fragmin laboratory control before each injection is not needed. Administration of nonfractionated and fractionated heparins must be combined with bandaging of the lower limbs and other measures of nonspecific prevention of thrombogenesis.