Zero-field magnetic skyrmions in exchange-biased ferromagnetic-antiferromagnetic bilayers.

We report on the stabilization of ferromagnetic skyrmions in zero external magnetic fields, in exchange-biased systems composed of ferromagnetic-antiferromagnetic (FM-AFM) bilayers. By performing atomistic spin dynamics simulations, we study cases of compensated, uncompensated, and partly uncompensated FM-AFM interfaces, and investigate the impact of important parameters such as temperature, inter-plane exchange interaction, Dzyaloshinskii-Moriya interaction, and magnetic anisotropy on the skyrmions appearance and stability. The model with an uncompensated FM-AFM interface leads to the stabilization of individual skyrmions and skyrmion lattices in the FM layer, caused by the effective field from the AFM instead of an external magnetic field. Similarly, in the case of a fully compensated FM-AFM interface, we show that FM skyrmions can be stabilized. We also demonstrate that accounting for interface roughness leads to stabilization of skyrmions both in compensated and uncompensated interface. Moreover, in bilayers with a rough interface, skyrmions in the FM layer are observed for a wide range of exchange interaction values through the FM-AFM interface, and the chirality of the skyrmions depends critically on the exchange interaction.

Coupled atomistic spin-lattice simulations of ultrafast demagnetization in 3d ferromagnets.

Despite decades of research, the role of the lattice and its coupling to the magnetisation during ultrafast demagnetisation processes is still not fully understood. Here we report on studies of both explicit and implicit lattice effects on laser induced ultrafast demagnetisation of bcc Fe and fcc Co. We do this using atomistic spin- and lattice dynamics simulations following a heat-conserving three-temperature model. We show that this type of Langevin-based simulation is able to reproduce observed trends of the ultrafast magnetization dynamics of fcc Co and bcc Fe. The parameters used in our models are all obtained from electronic structure theory, with the exception of the lattice dynamics damping term, where a range of parameters were investigated. It was found that while the explicit spin-lattice coupling in the studied systems does not impact the demagnetisation process notably, the lattice damping has a large influence on the details of the magnetization dynamics. The dynamics of Fe and Co following the absorption of a femtosecond laser pulse are compared with previous results for Ni and similarities and differences in the materials' behavior are analysed. For all elements investigated so far with this model, we obtain a linear relationship between the value of the maximally demagnetized state and the fluence of the laser pulse , which is in agreement with experiments. Moreover, we demonstrate that the demagnetization amplitude is largest for Ni and smallest for Co. This holds over a wide range of the reported electron-phonon couplings, and this demagnetization trend is in agreement with recent experiments.

[Growth hormone - 30 years of clinical practice: past, present, future].

The recombinant technologies era, which began in the second half of the XX century, made it possible to produce recombinant growth hormone (rGH) necessary for the treatment of stunting of various genesis. The time of practically unlimited possibilities of rGH production has come, which served as a stimulus for studying the efficacy and safety of rGH application, searching for optimal ways of its use and dosing regimes. Many years of experience in the use of somatropin in clinical practice allowed us to obtain data on its effectiveness primarily in somatotropic insufficiency in children, to study its effect on the functional state of various organs and systems, and to expand the indications for the use of RGR.

[Replicative and biochemical ageing mechanisms among females with Turner syndromes].

BACKGROUND: 2025 is going to be the 100th anniversary of the first historical description of Turner syndrome - complex of  genomic abnormalities, congenital gonadal disruption and hypergonadotropic hypogonadism. Total estrogenic deficiency triggers development of age-related comorbidities. There is no doubt that personalized search for replicative markers of cellular aging among females with Turner syndrome is needed. AIM: To evaluate features of replicative (telomere length) and biochemical (lipid profile, calcium-phosphate album, thyroid hormones, markers cytolysis and cholestasis, carbohydrate metabolism, nitrogenic metabolism, electrolytes, FSH) markers among females with Turner syndrome. MATERIALS AND METHODS: Research has been provided in collaboration between Endocrinology Research Centre of the Russian Ministry of Health and Lomonosov Moscow State University Medical Research and Educational Centre in the period since 10.01.2021 until 01.08.2022. Females with non-iatrogenic hypergonadotropic hypogonadism caused by Turner syndrome (45,X0; 45,X/46,XX; 45,X/46,X,r(X); 13-40 y.o.; n=26) and primary ovarian insufficiency (18-39 нyears=26); healthy females of reproductive age (15-49 y.o.; n=24). Patients have undergone laboratory genetic (leucocyte telomere length), biochemical (fasting glycaemia, urea, creatinine, common/conjugated bilirubin, ALT, AST, gamma-glutamyl transferase, triglycerides, HDL-P, LDL-P, common cholesterol, common/ionized calcium, phosphate, vitamin D, sodium/potassium/chlorides, FSH, HbA1c) analyses. Body measurements - body mass, body height. DNA extraction - provided with Qiagen DNA blood mini kit (Germany). Leukocyte telomere length - with real-time polymerase chain reaction PCR (Flow-fish). Soft program IBM SPSS Statistics (version 26,0 for Windows). RESULTS: 1. Females with Turner syndrome have significantly lower mean telomere length (8,22 kB [6,63-9,30]) than with primary ovarian insufficiency (10, 34 кБ [8,41-13,08], p<0,001) and healthy reproductive age females (10,77 kB [9,95-13,16], р>0,05).2. Telomere length correlates directly and significantly with longevity of menopausal hormonal therapy among females with primary ovarian insufficiency (ρ = 505; p<0,001).3. Patients with Turner syndrome are inclined to vitamin D deficiency (р<0,001), dyslipidemia (р=0,01); increase of levels of aminotransferases, cholestasis markers, phosphate and FSH (р<0,001). CONCLUSION: Turner syndrome is serious genetic disease that leads not only to infertility but to significant decrease of quality/life longevity out of "healthy aging" conception.

[Telomere pathology in ontogenesis in patients with Turner syndrome].

According to present medical databases there many trials to provide in vivo researches in vivo to confirm/refute shortening process of telomeres among patients with Turner syndrome. Despite the successful clinical experience of providing such patients with Turner syndrome, a lot of omics (proteomic and metabolomic) aspects still stay unclear. Main disadvantages of most researches are small volume and minimized mathematical correlation with chronic disease (coronary heart disease, essential hypertension, cardiovascular malformations). Finally, organization of international prospective multi-centered researches in vivo including patients with mosaic cariotype and co-operation between physicians and biologists are optimal solutions for this present problem.

[Intra- and postoperative correction of bradycardia by transesophageal electric stimulation].

The authors describe a case of clinical use of transesophageal pacing to correct drug-induced bradycardia during anesthesia, surgery, and in the early postoperative period in a geriatric patient with severe cardiovascular comorbidity who has been long receiving a beta-adrenoblocker. They show it possible to employ the procedure long in the therapy of bradyarrhythmias resistant to the cholinolytic atropine.

Socioethnic diversity of family structure.

PIP: Variations in family structure among social and ethnic groups in the Moldavian SSR are examined, with emphasis on rural and urban differences. Aspects considered include marriage rates, age at marriage, socioeconomic status, family size and type, the percentage of single persons, birth rates, marriage between members of different socioeconomic classes or ethnic groups, and the incidence of divorce. Data are primarily from the 1970 census.^ieng