RESUMEN
We propose a circuit-level model combining the Marcus-Hush-Chidsey electron current equation and the Yakopcic equation for the state variable for describing resistive switching memory devices of the structure metal-ionic conductor-metal. We extend the dynamics of the state variable originally described by a first-order time derivative by introducing a fractional derivative with an arbitrary order between zero and one. We show that the extended model fits with great fidelity the current-voltage characteristic data obtained on a Si electrochemical metallization memory device with Ag-Cu alloy.
RESUMEN
By employing density functional theory calculations, we explore the initial stage of competitive alloying of co-deposited silver and indium atoms into a silicon surface. In particular, we identify respective adsorption positions and activation barriers governing their diffusion on a dimer-reconstructed silicon surface. Furthermore, we develop a growth model that appropriately describes diffusion mechanisms and silicon morphology with the account of silicon dimerization and the presence of C-type defects. Based on the surface kinetic Monte Carlo simulations, we examine the dynamics of bimetallic adsorption and elaborate on the temperature effects on the submonolayer growth of an Ag-In alloy. A close inspection of adatom migration clearly indicates effective nucleation of Ag and In atoms, followed by the formation of orthogonal atomic chains. We show that the epitaxial bimetallic growth might potentially lead to exotic ordering of adatoms in the form of anisotropic two-dimensional lattices via orthogonally oriented single-metal rows. We argue that this scenario becomes favorable provided above room temperature, while our numerical results are shown to be in agreement with the experimental findings.
RESUMEN
In itinerant magnets, the indirect exchange coupling of Ruderman-Kittel-Kasuya-Yosida type is known to stabilize incommensurate spin spirals, whereas an account of higher order spin interactions favors the formation of a noncoplanar magnetic texture. This is manifested by the finite Berry phase the conduction electrons accumulate when their spins follow this texture, leading thus to the topological Hall effect. We herein utilize the effective spin model with bilinear-biquadratic exchange interactions for studying the formation of the magnetic hedgehog lattice, that represents a periodic array of magnetic anti- and monopoles and has been recently observed in the B20-type compounds, in a three-dimensional itinerant magnet. As opposed to widely used Monte Carlo simulations, we employ a neural-network-based approach for exploring the ground state spin configuration in a noncentrosymmetric crystal structure. Further, we address the topological Hall conductivity, associated with nonzero scalar spin chirality, in the itinerant magnet due to the coupling to the spin hedgehog lattice, and provide the evidence of a magneto-optic Kerr effect.
RESUMEN
The effects of septoplasty and sinus lifting simulation in rats on changes in the frequency domain of heart rate variability were compared. In the early postoperative period, the low-frequency component increases, and the high-frequency component decreases. The VLF range also increased. This indicates an increase in the activity of the sympathetic nervous system and a shift in metabolism under the influence of post-surgical inflammation.
Asunto(s)
Frecuencia Cardíaca/fisiología , Inflamación/fisiopatología , Tabique Nasal/cirugía , Animales , Masculino , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Ratas , Ratas Wistar , Elevación del Piso del Seno Maxilar , Sistema Nervioso Simpático/fisiopatologíaRESUMEN
As practice shows, there are many alternative drugs that cause drug damage to the liver. A case of medicinal damage to the liver with an immunomodulatory herbal preparation Immunostimulating collection, which included St. John's wort, Elecampane, Kopeichnik, Echinacea, Licorice, Rosehip, is presented. A 39-year-old patient came to the clinic with complaints of yellowing of the skin, whites of the eyes, heaviness in the epigastrium after eating, lightening of feces, dark urine, sour taste in the mouth, bloating, pruritus, decreased appetite, pronounced general weakness, drowsiness 10 days after you start taking herbal immunostimulant. The diagnosis of drug damage to the liver was made taking into account the history and laboratory parameters, since the patient had negative markers of viral hepatitis and increasing of biochemical blood tests: alanine transferase up to 2800 U/l (norm up to 32 U/L), aspartate transferase up to 1776 U/l (norm up to 31 U/l), total bilirubin up to 577 U/l (norm up to 21 U/l), direct bilirubin up to 116 U/l (norm up to 4.3 U/l), alkaline phosphatase up to 112 U/l (norm up to 98 U/l). After the withdrawal of the immunomodulator and the appointment of therapy, including diet, enzyme replacement therapy, drugs clinical and laboratory manifestations of liver drug damage completely disappeared. This confirms the leading role of the immunoactive drug, which the patient took in the toxic effect on the liver.
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Enfermedad Hepática Inducida por Sustancias y Drogas , Humanos , Adulto , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Agentes Inmunomoduladores , Fosfatasa Alcalina , Ácido Aspártico , Extractos Vegetales/efectos adversos , Bilirrubina , Transferasas , Adyuvantes Inmunológicos , AlaninaRESUMEN
The etiological structure of urinary tract infections (UTI) is determined by the leading role of uropathogenic Escherichia coli (UPEC). The aim of the work is to study the biological properties and phylogenetic diversity of E. coli strains isolated from UTI in outpatient and inpatient patients. METHOD: s and materials. 198 clinical UPEC strains were studied, 105 of which were designated as polyclinic and 93 as nosocomial (73 are isolated from urine and 20 are from catheter surface 48 hours after hospitalization). UPEC phylogenetic groups were determined by polymerase chain reaction (quadruplex PCR) according to O. Clermont et al. (2013). RESULTS: Among polyclinic cultures, representatives of all eight recognizable phylogroups were found; strains of UPEC phylogroup B2 (37.1%), E (13.3%) and F (8.6%) were most often found. Nosocomial cultures in almost 90% of cases belonged to the phylogroup B2, to which all the catheter-associated strains were assigned. The E. coli of the phylogroup B2, both in the mono-species and in the polymicrobial associations, was authentically more often isolated in the hospital than in the polyclinic (p<0.00001), whereas the bacteria of the phylogroup E, on the contrary, in the polyclinic (p<0.0001) . The hemolytic activity and biofilm-forming ability of UPEC strains did not differ in the two groups, while in the hospital hemolytic E. coli of the B2 phylogroup was significantly more likely than the polyclinic (p<0.001). In addition, B2 strainsformed biofilms in more than 60% cases. Regardless of the source of isolation, the strains were resistant to ampicillin (62.1%), amoxicillin/clavulanate (27.8%), cefotaxime (37.9%) and ciprofloxacin (36.9%). The production of ESBL was detected in fifty-one (25.8%) cultures, with a statistically significant difference in nosocomial strains: urinaryAsunto(s)
Infecciones por Escherichia coli
, Infecciones Urinarias
, Escherichia coli Uropatógena
, Ciprofloxacina
, Humanos
, Filogenia
RESUMEN
Matter in nontrivial topological phase possesses unique properties, such as support of unidirectional edge modes on its interface. It is the existence of such modes which is responsible for the wonderful properties of a topological insulator - material which is insulating in the bulk but conducting on its surface, along with many of its recently proposed photonic and polaritonic analogues. We show that exciton-polariton fluid in a nontrivial topological phase in kagome lattice, supports nonlinear excitations in the form of solitons built up from wavepackets of topological edge modes - topological edge solitons. Our theoretical and numerical results indicate the appearance of bright, dark and grey solitons dwelling in the vicinity of the boundary of a lattice strip. In a parabolic region of the dispersion the solitons can be described by envelope functions satisfying the nonlinear Schrödinger equation. Upon collision, multiple topological edge solitons emerge undistorted, which proves them to be true solitons as opposed to solitary waves for which such requirement is waived. Importantly, kagome lattice supports topological edge mode with zero group velocity unlike other types of truncated lattices. This gives a finer control over soliton velocity which can take both positive and negative values depending on the choice of forming it topological edge modes.