Analogue of electromagnetically induced transparency in square slotted silicon metasurfaces supporting bound states in the continuum.

In this work, a silicon metasurface designed to support electromagnetically induced transparency (EIT) based on quasi-bound states in the continuum (qBIC) is proposed and theoretically demonstrated in the near-infrared spectrum. The metasurface consists of a periodic array of square slot rings etched in a silicon layer. The interruption of the slot rings by a silicon bridge breaks the symmetry of the structure producing qBIC stemming from symmetry-protected states, as rigorously demonstrated by a group theory analysis. One of the qBIC is found to behave as a resonance-trapped mode in the perturbed metasurface, which obtains very high quality factor values at certain dimensions of the silicon bridge. Thanks to the interaction of the sharp qBIC resonances with a broadband bright background mode, sharp high-transmittance peaks are observed within a low-transmittance spectral window, thus producing a photonic analogue of EIT. Moreover, the resonator possesses a simple bulk geometry with channels that facilitate the use in biosensing. The sensitivity of the resonant qBIC on the refractive index of the surrounding material is calculated in the context of refractometric sensing. The sharp EIT-effect of the proposed metasurface, along with the associated strong energy confinement may find direct use in emerging applications based on strong light-matter interactions, such as non-linear devices, lasing, biological sensors, optical trapping, and optical communications.

Transition between toroidic orders in dielectric metasurfaces by polarization of the incident wave.

We propose a design and perform a theoretical and experimental study of optical properties of a metasurface composed of hexagonal oligomers of dielectric particles that somewhat resemble characteristics of multiferroics. It can maintain both toroidic and antitoroidic orders in the dynamical response on irradiation by a linearly polarized plane wave. These orders originate from the dark states of toroidal dipole moments. Due to the consciously chosen perturbation in the oligomers, the orders are excited at the same frequency by the wave with orthogonal polarization. The excitation of these orders results in different characteristics of the electric near-field localization. This has significant potential for several applications, which are thoroughly discussed.

Superfluid ß phase of

It is known that in low magnetic fields the superfluid transition of ^{3}He in nematic aerogel occurs into the polar phase. Using a vibrating aerogel resonator, we observe that in high magnetic fields this transition splits into two discrete transitions, occurring at different temperatures. According to theoretical models, a new superfluid phase-the ß phase-should be realized between these two transitions. The temperature range of existence of the new phase is measured as a function of magnetic field. The results are well consistent with theoretical expectations for the ß phase.

[Age characteristics of primary disability of adult population due to diseases of digestive organs in the Belgorod region during 2010-2018.]

The analysis of indicators of primary disability due to diseases of digestive organs among pension age and working-age population of the Belgorod region is carried out in comparative aspect with the national indicators during 8 years. Rank places of diseases of digestive organs in structure of primary disability were defined. The revealed main features and trends of disability, were investigated to further optimization of medico-social service and improved support to this contingent of disabled people.

[Gerontological aspects of the demographic situation in the Belgorod region, 2010-2018.]

In the Belgorod region during 2010-2018 the total number of the population slightly increased by 1,3%, until 2017 only because of migratory gain. After 2018 it does not compensate natural decrease of the population. During the analyzed period from 2010 to 2018 the negative demographic trends which are characterized by depopulation owing to decrease in birth rate, growth of mortality and ageing of the population took place.

Effect of Magnetic Boundary Conditions on Superfluid

We report results of experiments with superfluid ^{3}He confined in aerogels with parallel strands which lead to anisotropic scattering of ^{3}He quasiparticles. We vary boundary conditions for the scattering by covering the strands with different numbers of atomic ^{4}He layers and observe that the superfluid phase diagram and the nature of superfluid phases strongly depend on the coverage. We assume the main reason for these phenomena is a magnetic channel of the scattering which becomes important at low coverages and can be essential in other Fermi systems with triplet pairing.

Bose-Einstein Condensation of Magnons and Spin Superfluidity in the Polar Phase of

The polar phase of ^{3}He, which is topological spin-triplet superfluid with the Dirac nodal line in the spectrum of Bogoliubov quasiparticles, has been recently stabilized in a nanoconfined geometry. We pump magnetic excitations (magnons) into the sample of polar phase and observe how they form a Bose-Einstein condensate, revealed by coherent precession of the magnetization of the sample. Spin superfluidity, which supports this coherence, is associated with the spontaneous breaking of U(1) symmetry by the phase of precession. We observe the corresponding Nambu-Goldstone boson and measure its mass emerging when applied rf field violates the U(1) symmetry explicitly. We suggest that the magnon BEC in the polar phase is a powerful probe for topological objects such as vortices and solitons and topological nodes in the fermionic spectrum.

[Primary uterine cervix melanoma]. / Pervichnaia melanoma sheiki matki.

The purpose of this paper is to present a rare clinical case of primary uterine cervix melanoma. Clinical data and histological specimens were a material for this investigation. The paper describes a case of primary uterine cervix melanoma in a 47-year-old patient who visited a gynecologist for contact bleeding from the genital tract. Squamous cell carcinoma was diagnosed by primary biopsy. Histologically, this tumor was referred to as a mixed tumor: there were large cell fields with epithelioid morphology and high mitotic activity among the small cell component. No pigment was detected. Immunohistochemical examination revealed the pronounced cytoplasmic expression of S-100 and a melanocytic cocktail (HMB-45 + tyrosinase + MelanA), a negative reaction in the tumor cells with smooth muscle actin and desmin and a positive reaction in the preserved myocytes, and the expression of cytokeratin AE1/AE3 exclusively in the non-keratinized surface stratified squamous epithelium. Primary epithelioid amelanotic melanoma was diagnosed.

[Age specific recurrent cancer disability of adult population in the Belgorod region in dynamics in 2000-2015.]

In the Belgorod region for 16 years of observation (2000-2015) number of persons who are annually recognized as recurrently disabled due to cancer increased by 113,4 %. Their specific weight increased from 6,9 up to 24,2 % and its average annual rate is 11,3%±5,9 of total number of recurrently disabled persons. In 2015 cancer as a reason of recurrent disability was on the 2d ranking place after cardiovascular system diseases. Cohort of persons recognized as recurrently disabled due to cancer include mainly persons of average (46,4%±9,9) and pension (27,7%±19,7) age, persons with disability groups II and III (37,2%±4,3 and 50,8%±4,1 respectively). With increasing age the degree of the recurrently granted disability group gets heavier. Specified negative dynamisc of levels, structure and trends of recurrent cancer disability of adult population shows the importance and great medical and social as well as economical significance of the problem.

[Hemorrhagic complications of percutaneous interventions for nephrolithiasis].

Hemorrhagic complications are one of the major problems of percutaneous urolithiasis interventions. AIM: To investigate the incidence of hemorrhagic complications after percutaneous nephrolithotripsy. MATERIAL AND METHODS: This was a comparative analysis of 146 percutaneous nephrolithotripsies. The study group comprised 81 patients with stag horn nephrolithiasis; the rest of the patients were assigned to the control group. RESULTS: Both groups were comparable in age and sex (p>0.05). The body weight of the patients in the study group was statistically significantly higher than in the control group, amounting to 94.1+/-15.4 and 68.3+/-9.6 kg, respectively (p<0.05), the body mass index in the study group averaged 45.9+/-7.6 kg/m2 versus 28.5+/-9.4 kg/m2 in the control group (p<0.05). 50.6% of the study group patients had urate urolithiasis. The blood loss depended on operative time and the number of accesses to the kidney. The incidence of hemorrhagic complications did not differ in both groups and was in the range of 16 to 16.9% (p> 0.05). Early hemorrhagic complications did not exceed Grade II, according to Clavien-Dindo classification. Anticoagulant and antiplatelet therapy did not increase the number of hemorrhagic complications. Arterial hypertension was the main risk factor for hemorrhagic complications. CONCLUSION: Arterial hypertension in patients scheduled for percutaneous nephrolithotripsy should be corrected. To stop ongoing renal bleeding, image-guided endovascular interventions should be used.

[Metaphylaxis of urolithiasis: new look, modern approach, implementation in a mobile application].

AIM: To analyze the sub-segment of mHealth devoted to assessing of the risk of recurrent stone formation and metaphylaxis of stone formation. To design a smartphone application (app.) in Russian language for urolithiasis patients. MATERIALS AND METHODS: Three working groups of urologists from three St. Petersburg clinics searched for downloadable medical applications relevant to the above requirements. After searching and analyzing existing medical applications, the most acceptable design and structure of our own application were identified. RESULTS: The developed "Urolithiasis" application is available for free download in Russian language versions in App Store (Apple, Inc.) and Google Play (Android market, Google, Inc.). It features the following sections: 1) "Take the test" (personalized calculation of the risk of kidney stone recurrence and providing relevant recommendations using ROKS nomogram), 2) "Water" (with reminders to drink water and automatic logging of the water intake), 3) "Food" (Nutrition facts on the content of calcium, oxalate, purine, protein, citrate and calories in common foods), 4) "My doctor" (in the future this option will allow for on-line communication with a patients physician), 5) "Feedback" (if the patient does not find the desired product or has a question - this section is for him/her). CONCLUSIONS: The smartphone application "Urolithiasis" in Russian may be recommended to patients with urolithiasis for improving the effectiveness of metaphylaxis.

Observation of Half-Quantum Vortices in Topological Superfluid

One of the most sought-after objects in topological quantum-matter systems is a vortex carrying half a quantum of circulation. They were originally predicted to exist in superfluid ^{3}He-A but have never been resolved there. Here we report an observation of half-quantum vortices (HQVs) in the polar phase of superfluid ^{3}He. The vortices are created with rotation or by the Kibble-Zurek mechanism and identified based on their nuclear magnetic resonance signature. This discovery provides a pathway for studies of unpaired Majorana modes bound to the HQV cores in the polar-distorted A phase.

[Life Threatening Complications in Patients With ST-Elevation Acute Coronary Syndrome-Dependence on Reperfusion Interventions (Data of Federal Register of Patients With Acute Coronary Syndrome)].

AIM: to study rate and type of life-threatening complications (LC) in patients with ST-Elevation (STE) Acute Coronary Syndrome (ACS) and their relation to implementation of reperfusion measures. MATERIAL AND METHODS: Database of the Federal Register of patients with ACS (FRACS) which functioned from 01/01/2009 to 01/01/2014 contains information on 212304 patients with verified diagnosis of ACS. From this pool using random number generator we selected a cohort comprising 10348 patients with STEACS (60% men, mean age 63.5+/-0.1 clinical systolic and diastolic arterial pressure [AP] 135.2+/-0.3 and 81.9+/-0.2 mm Hg, respectively). Killip class was used for determination of degree of acute heart failure. RESULTS: Most frequent forms of LC were heart rhythm disturbances (6.2%) and cardiogenic shock (5.4%). Patients subjected to percutaneous coronary intervention (PCI) including those in whom pharmacoinvasive approach was used had less LC and lower hospital mortality than patients who received only thrombolytic therapy (TLT). Reperfusion measures were administered mostly to patients with class I-II acute heart failure. Hospital mortality was highest (9.47%) among patients not subjected to reperfusion measures and lowest (1.09%) among patients treated with PCI+TLT. CONCLUSION: FRACS assesses LC in patients with STEACS in the context of implemented reperfusion measures. Data of FRACS can be used by the health service authorities for improvement of medical aid to patients with STEACS.

Polar Phase of Superfluid (3)He in Anisotropic Aerogel.

We report the first observation of the polar phase of superfluid (3)He. This phase appears in (3)He confined in a new type of aerogel with a nearly parallel arrangement of strands which play the role of ordered impurities. Our experiments qualitatively agree with theoretical predictions and suggest that in other systems with unconventional Cooper pairing (e.g., in unconventional superconductors) similar phenomena may be found in the presence of anisotropic impurities.

Measurement of the two-photon exchange contribution to the elastic e(±)p scattering cross sections at the VEPP-3 storage ring.

The ratio of the elastic e(+)p to e(-)p scattering cross sections has been measured precisely, allowing the determination of the two-photon exchange contribution to these processes. This neglected contribution is believed to be the cause of the discrepancy between the Rosenbluth and polarization transfer methods of measuring the proton electromagnetic form factors. The experiment was performed at the VEPP-3 storage ring at beam energies of 1.6 and 1.0 GeV and at lepton scattering angles between 15° and 105°. The data obtained show evidence of a significant two-photon exchange effect. The results are compared with several theoretical predictions.

[THE UNESTERIFIED AND FREE FATTY ACIDS OF BLOOD PLASMA, DISTAL AND PROXIMAL PART OF ARTERIAL BED, VEGETATIVE INNERVATION AND PATHOGENESIS OF METABOLIC ARTERIAL].

The stages of phylogenesis were used as a basis for sequential formation of humoral (hormonal) regulation and later neurohumoral regulation. Hereinafter, under becoming of biological function of locomotion nervous regulation was formed. At late stages of phylogenesis under formation of closed system of blood circulation, biological function of adaptation began using under regulation (compensation) of biological reaction metabolism-micro-circulation (M-M) hydrodynamic pressure too on a par with phylogenetically earlier biological reactions of compensation and stress. It can be assumed that in phylogenesis physical factors (hydrodynamic pressure and thermogenesis or hyperpyrexia) became effective regulators of metabolism at the level of organism. If patient suffers from increasing of arterial pressure the questions to be answered are--what disorders of metabolism in vivo it is called to compensate, what biological function is disordered and how these disorders of metabolism can be detected and normalized. The initial disorders of biological reaction M-M can be developed in any paracrin cenosis of cells, organ or system of organs. If local regulation (compensation) at the level of paracrin cenosis under effect of humoral mediators turned out ineffective compensation will form at the level of organism under realization of hydraulic and hydrodynamic regulation of metabolism. This kind of regulation can be described as optimal only partly. Because of imperfection of hydrodynamic systemic regulation of metabolism, independently of in how many sets of paracrin cenosis in vivo occurs formation of a physiological biologic reaction M-M, with time in pathological process target organs will be involved primarily kidneys, brain and more rarely lungs and later on heart.

[Obesity as pathology of adipocytes: number of cells, volume of arterial bloodstream,local pools of circulation in vivo, natriuretic peptides and arterial hypertension].

The non-specific systemic biological reaction of arterial pressure from the level of organism. vasomotor center and proximal section of arterial bloodstream is appealed to compensate disorders of metabolism and microcirculation in distal section of arteries. This phenomenon occurs in several cases. The primarily local disorders of metabolism at autocrine level, physiological (aphysiological) death of cells, "littering" of intercellular medium become the cause of disorder of microcirculation in paracrin cenosises and deteriorate realization of biological functions of homeostasis, trophology, endoecology and adaptation. The local compensation of affected perfusion in paracrin cenosises at the expense of function of peripheral peristaltic pumps, redistribution of local bloodflow in biological reaction of endothelium-depended vaso-dilation has no possibility to eliminate disorders in realization of biological functions. The systemic increase of arterial pressure under absence of specific symptoms of symptomatic arterial hypertension is a test to detect disorder of biological functions of homeostasis, trophology, biological function of endoecology and adaptation. Allforms of arterial hypertension develop by common algorithm independently from causes of disorders of blood flow, microcirculation in distal section of arteries. The non-specific systemic compensation ofdisorders of metabolism from level of organism, in proximal section of arterial bloodstream always is the same one and results in aphysiological alterations in organs-targets. To comprehend etiological characteristics of common pathogenesis of arterial hypertension is possible in case of application of such technically complicated and still unclear in differential diagnostic of deranged functions modes of metabolomics.

[The pharmacokinetics of colistin under parenteral injection of sodium colistimitate in children with chemically induced neutropenia].

The prevalence of hospital strains of P. aeruginosa, A. baumannii and K. pneumoniae characterizing by multiple drug resistance to overwhelming majority of antibiotics anew evoked an increased interest to colistin. However, until now there is not enough information concerning pharmacokinetics of colistin to optimize dosage of this pharmaceutical. The study was carried out to analyze pharmacokinetics of both colistin and sodium colistimitate in children with chemically induced neutropenia. To quantitatively detect colistin in blood serum the technique of highly effective fluid chromatography with mass spectrometry was applied. The concentration of colistin was detected in 21 children with chemically induced neutropenia (13 patients with septicemia, 8 children of control group) after intravenous injection of sodium colistimitate. The significant variability of pharmacokinetic parameters of colistin was established both in patients with septicemia and in control group. The technique of highly effective fluid chromatography with mass spectrometry can be applied for therapeutic medicinal monitoring and optimization regimen of dosage.

[Cystatin C and preclinical lesions in the target organs of hypertensive patients].

AIM: To study the association between cystatin C levels and preclinical lesions in the target organs (heart, kidney, vessels) of patients with hypertensive disease (HD) at moderate and high risks for cardiovascular events (CVE). SUBJECTS AND METHODS: The investigation enrolled 47 patents (30 men and 17 women) with Stages I-II HD at moderate (n = 23) and high (n = 24) risks for CVE. The patients' mean age was 46.0 ± 1.8 years; the duration of HD was 4.1 ± 0.2 years. The blood level of cystatin C was estimated by photometry using a biochemical autoanalyzer. Glomerular filtration rate (GFR) was calculated by the MDRD formula. Microalbuminuria (MAU) was determined by turbidimetry employing a biochemical autoanalyzer. RESULTS: No association between cystatin C level and 24-hour blood pressure (BP) monitoring readings was found in the patients except the men in whom it was correlated with 24-hour diastolic BP (DBP) (r = 0.36; p < 0.05). The hypertensive patients showed a positive correlation of cystatin C with their age (r = 0.51; p < 0.001). There were higher cystatin C levels in smoking patients with HD (n = 19) and no statistically significant differences in the level of MAU, urine uric acid, and GFR between them. There was a statistically highly significant negative. correlation between cystatin C concentration and GFR by the MDRD formula (r = -0.59; p < 0.001), at the same time, no correlation was found between creatinine clearance (by the Cockroft-Gault formula). There were no statistically significant differences in cystatin C levels in relation to the presence or absence of carotid atherosclerosis (1.01 ± 0.03 and 0.93 ± 0.02 mg/l, respectively; p = 0.08). Overall, there was a positive correlation of cystatin C levels with left ventricular mass index (r = 0.58; p < 0.001) and relative myocardial thickness index (r = 0.40; p < 0.05). CONCLUSION: The findings of the association of cystatin C and 24-hour DBP, preclinical lesions in the heart, vessels, and kidney seem to argue for the concept of cardiorenal syndrome in patients with HD just at its early stages.

Chiral properties of structure and magnetism in Mn(1-x)Fe(x)Ge compounds: when the left and the right are fighting, who wins?

Magnetic susceptibility measurements have shown that the compounds Mn(1-x)Fe(x)Ge are magnetically ordered through the whole range of concentrations x = [0.0,1.0]. Small-angle neutron scattering reveals the helical nature of the spin structure with a wave vector, which changes from its maximum (|k| = 2.3 nm(-1)) for pure MnGe, through its minimum (|k| → 0) at x(c) ≈ 0.75, to the value of |k| = 0.09 nm(-1) for pure FeGe. The macroscopic magnetic measurements confirm the ferromagnetic nature of the compound with x = x(c). The observed transformation of the helix structure to the ferromagnet at x = x(c) is explained by different signs of chirality for the compounds with x > x(c) and x