•The problem of the motion of a magnetic vortex/skyrmion is solved taking into account the inertial term and the gyroscopic term of the third order.•The trajectory undergoes a break, similar to the ...refraction of light at the boundary of media.•Expressions are obtained for the potential energy of a magnetic vortex for defects of different types.
In this paper, the problem of a magnetic vortex motion in a field of extended linear inhomogeneity is solved theoretically. The motion parameters are calculated by the method of collective variables (Thiel’s equation) with the vortex effective mass and the third-order gyrovector. On the basis of the equation of motion, the influence of the core mass and the third-order gyrovector on the character of the vortex motion as a quasiparticle is analyzed. Using the method of magnetostatic charges, analytical expressions are obtained for the effective potentials where the vortex core is located: (a) near the edge of the magnet or at the boundary of different magnetic phases, (b) near the linear inhomogeneity of local anisotropy (bidirectional and unidirectional). The solution of the equation of motion made it possible to obtain the trajectories of the core in various physical situations. In addition, the paper discusses the features of the Hall effect for vortices/skyrmions, which are provided by the inertial properties and a third-order gyrovector. It is shown that when the core of a linear inhomogeneity crosses a unidirectional anisotropy or the boundary of magnetic phases, a curvature of the trajectory is observed, which is similar to the refraction of light at the boundary of optically dissimilar environment. It is important to note that the introduction of the mass and gyroscopic effect of the third order in the equation of motion showed that the motion of the vortex, even in a homogeneous potential, is not translational. In this case, the trajectory is an overlay of cycloids of different rotation frequencies (analytical expressions are obtained for the frequencies). It is shown that, the introduction of the mass and the gyroscopic term of the third order, the motion of the vortex core cannot be considered translational at least during the time of the transition mode until the stationary mode of motion takes place.
Undoped and Mg-doped Nd2MoO6 oxymolybdate single crystals and polycrystalline samples have been prepared by flux growth and solid-state reactions. The materials have been characterized by X-ray ...diffraction, EDS microanalysis, X-ray structure analysis, differential scanning calorimetry, thermogravimetry, and impedance spectroscopy. The (MgO)x(Nd2MoO6)(1–x)/2 solid solution series has been shown to extend to x = 0.20. Doping of Nd2MoO6 single crystals with Mg leads to splitting of the Mo, Nd1, and O2 sites. A structural model in which the Mg atoms partially substitute for Mo atoms and reside near the Mo site, 0.28 Å from it, ensures the best agreement with the observed diffraction pattern. The conductivity of the undoped and doped polycrystalline samples approaches 10−4 S/cm at 800 °C and is assumed to have an anionic nature.
Ovarian hyperstimulation syndrome (OHSS) is the most severe and life-threatening complication of assisted reproductive technologies (ART). OHSS is based on an excessive ovarian response to ovarian ...stimulation; however, the pathogenesis has not been fully understood yet. The most serious complications of OHSS are thromboembolic complications and ovarian torsion. The current study describes the risk factors for the development of ovarian hyperstimulation syndrome and proposes a method for specific prediction of this syndrome. This study was designed to investigate 671 therapeutic cycles in the IVF program during 2009-2018. All patients were divided into two groups. Group one (n=56) included women who developed OHSS during the IVF procedure. Group two (n=615) consisted of women who did not have this complication during the IVF procedure. All the observation and examination outcomes were entered into a specially developed questionnaire, and then into a Microsoft Excel spreadsheet. The data were processed by variable statistics using Statistica 10.0. Analyzing of the recorded data revealed that the rate of OHSS was higher in the group of younger women, aged 30.76±3.67 years, in comparison with those aged 32.78±4.40 years in the group of patients without OHSS (
<0.05). The analysis of the initial phase of the reproductive system has confirmed that the group of patients with OHSS had a higher level of prolactin, 462.84±191.56 mIU/L in comparison with 363.43±187.84 mIU/L, which corresponded to the group of women without OHSS (p<0.05). In our results, 7.15±1.04% of cases with OHSS had obesity, while of the patients from the group without OHSS suffered from it (
<0.05). OHSS is the most severe iatrogenic complication of ART, therefore it is extremely important to consider its risk factors and take timely preventive measures. This study has established a high relationship between the studied risk factors and ovarian hyperstimulation syndrome and proposed a model for predicting this syndrome.
Preeclampsia (PE) is a severe complication of pregnancy accompanied by arterial hypertension, edema, or proteinuria with impaired functioning
of various organs and systems. It is also an important ...medical and social problem, which has been one of the leading causes of maternal
and perinatal mortality and morbidity worldwide. Despite the achievements of modern medicine, the etiology of this pathology is still
unknown. Recently, many scientists have especially focused on the study of genetic factors underlying the etiopathogenesis of PE, namely,
the contribution of individual polymorphic loci of various candidate genes. The current study aimed to investigate the clinical
characteristics of PE and the contribution of the polymorphic loci rs1042838 of Progesterone Receptor (PGR) gene and rs8068318
of the T-Box Transcription Factor 2 (TBX2) gene to the development of PE. The study was conducted on 219 women with PE with the
mean±SD age of 26.52±5.51 years and 329 women with the physiological course of pregnancy as the control group with the mean±SD
age of 26.27±4.88 years. In total, 64.20%, 68.29%, 16.44%, 98.63%, and 35.48% of women with PE had increased systolic and normal
diastolic blood pressure (SBP and DBP) values, proteinuria, edema, and overweight (BMI≥25), respectively. In the control group,
100%, 1.53%, 1.12%, and 35.48% of cases had normal SBP values with no proteinuria, DBP>90 mm Hg, edema, and overweight (BMI≥25),
respectively. An association was observed between the CC genotype of the rs8068318 polymorphism of the
TBX2
gene with the risk
of developing PE in women with PE (OR=2.12, 95%CI: 1.14-3.92,
P
=0.02). In addition, there was an association between the rs8068318
TBX2
polymorphic locus with lower SBP (Me=140, Q25 – Q75 130 – 142.5,
P
=0.01) and PBP (Me=50, Q25 – Q75 40 – 55,
P
<0.01). According to the
GeneCards database, the TBX2 gene, a member of a phylogenetically conserved gene family, is located on the long arm of chromosome 17
and encodes the TBX2 T-box transcription factor protein, which is a regulator of the transcriptional activity of various genes
(i.e., it suppresses the expression of
CDKN2A
(p19/ARF), inhibits cyclin-dependent kinase p21 Cip1 (
CDKN1A
),
and affects the expression of
MYC, RAS, BRCA1,
and
BRCA2
genes).
The problem of the frequency spectrum of collective gyrotropic modes in a finite linear chain of magnetostatically interacting ferromagnetic disks has been considered. It has been shown that by ...analyzing the frequency spectrum, one can derive information about the magnetization eddy state for each of the nanodisks in the chain. The feasibility of recording the frequency spectrum as a tool for data readout in magnetic memory devices has been discussed.
The features of the magnetic state of an array of parallel oriented permalloy ribbons are discussed. The arrays are made by explosive lithography. The ribbons have a thickness of 180 nm, a width of ...2.8 µm, and a length of about 4 mm. The distance between ribbons in different samples varies in the range from 300 nm to 4 μm. It is found that the ribbons in the regions far from the end faces are in a single-domain state with small-angle ripples, the magnetization distribution of which correlates with inhomogeneities of the ribbon side surfaces. Moreover, there is a distinct relationship in the spatial distribution of the ripples between adjacent ribbons with a relatively small distance between them. This makes it possible to evaluate the role of the magnetostatic coupling of magnetic subsystems of array elements and to estimate the characteristic value of the random stray field that pins the magnetization.
The problem of propagation of a magnetic inhomogeneity in the form of a magnetic vortex near a defect simulated by a crystallite with uniaxial anisotropy has been solved theoretically. The defect ...(crystallite) is implanted into a homogeneous 2D ferromagnetic matrix. Apart from the anisotropy energy, the term responsible for the existence of a centrosymmetric potential is included into the total energy. For calculations, we have used the method of collective variables (Thiele equation). We have considered the variants of bidirectional and unidirectional anisotropy of the crystallite. Analysis of the equations of motion for different directions of the anisotropy axis of the implanted defect has revealed the variety in the behavior of the vortex core as a quasiparticle. The vortex core can be trapped by the defect with equilibrium position of the vortex at rest directly on the crystallite or during its motion at a certain distance from it. It is shown that for a small damping parameter and in the case when the defect anisotropy axis lies in the plane of the magnet, the vortex moves so as if its core experiences the action of the repulsive axially symmetric potential.
The article is devoted to the development of innovative potential of the personnel based on knowledge management. The controversy surrounding the concept of innovative potential is highlighted. ...Current trends in human resources management are described. The interpretation of the aforementioned concept as a dynamic process of self-development of the personnel is substantiated. Key competencies, dynamic, organizational and absorbing capabilities of an enterprise that are being formed as part of the knowledge management system created at the enterprise are included in the list of the main characteristics of the stated potential. It is stressed that continuous staff training should be the main block of the system. The need to integrate the knowledge management system into the innovative business model of the organization is substantiated. Therefore, the company will transform into a self-learning one and eventually, with the maximum number of employees involved in the continuous training system, a company of intellectual resources that does not only accumulate but also capitalises knowledge. It is stated that corporate universities and educational centers established at organizations should become an effective way to accumulate and share corporate knowledge.
This article discusses the problem of the optimal distribution of labor resources by investment region, taking into account changing conditions. A deterministic model is considered, that is, both the ...investment region and the invested resources go into new states with a probability equal to one. Several economic agents jointly organize the process of investing labor resources in several investment regions.
Ring chromosome 18 is a rare chromosomal disorders that usually originate de novo and correlate with clinical manifestation: developmental delay as well as microcephaly, brain and ocular ...malformations, hypotonia and skeletal abnormalities. We generate iPSC clonal cell line ICGi024-A with pluripotency properties which were demonstrated in vitro by three germ layer differentiation capacity. ICGi024-A can be used for disease modeling and fundamental investigation of ring chromosome instability.
PDF
