Little-Parks effect and multiquanta vortices in a hybrid superconductor--ferromagnet system

Within the phenomenological Ginzburg-Landau theory we investigate the phase diagram of a thin superconducting film with ferromagnetic nanoparticles. We study the oscillatory dependence of the critical temperature on an external magnetic field similar to the Little-Parks effect and formation of multiquantum vortex structures. The structure of a superconducting state is studied both analytically and numerically.Comment: 7 pages, 1 figure. Submitted to J. Phys.: Condens. Mat

Guided Modes in Negative Refractive Index Waveguides

We study linear guided waves propagating in a slab waveguide made of a negative-refraction- index material, the so-called left-handed waveguide. We reveal that the guided waves in left-handed waveguides possess a number of peculiar properties, such as the absence of the fundamental modes, mode double degeneracy, and sign-varying energy ux. In particular, we predict the existence of novel types of guided waves with a dipole-vortex structure of the Pointing vector.Comment: 4 pages, 4 figure

Phase diagram of a superconductor / ferromagnet bilayer

The magnetic field (H) - temperature (T) phase diagram of a superconductor is significantly altered when domains are present in an underlying ferromagnet with perpendicular magnetic anisotropy. When the domains have a band-like shape, the critical temperature Tc of the superconductor in zero field is strongly reduced, and the slope of the upper critical field as a function of T is increased by a factor of 2.4 due to the inhomogeneous stray fields of the domains. Field compensation effects can cause an asymmetric phase boundary with respect to H when the ferromagnet contains bubble domains. For a very inhomogeneous domain structure, Tc~H^2 for low H and Tc~H for higher fields, indicating a dimensional crossover from a one-dimensional network-like to a two-dimensional behavior in the nucleation of superconductivity.Comment: 6 pages, 7 figure

Experience and prospects for application of by-products of processing of fruits in the production of animal feed

The purpose of the research was to study the feasibility of using by-products of the industrial processing of fruits for the production of full-feed mixed fodders with the possibility of using these mixed feeds as the only feed in the diets of herbivorous fur animals (nutria, brown muskrat, steppe marmot). Studies of chemical composition and nutrition have shown that nontraditional ingredients can be included in the composition of feed. At their expense, you can save up to 30% of leguminous feed, 9% - cake, 1% - meat and bone meal. This allowed us to reduce the cost of the studied batches of feed by 18–21%. Experiments have shown the effectiveness of using such feed in the diets of herbivorous fur-bearing animals. The inclusion of compound feed in the diet allowed to increase the number of commercial offspring per female muskrat by 0.8 heads, compared to the control group. The safety of young animals until the moment of depositing puppies from their mothers was approximately equal in both groups. Young muskrats of the experimental groups had 5.5–6.8% higher values of average daily increments, compared to control analogues. A similar pattern is established in male nutria. Marmots of the experimental group from the very beginning of the experiment were outnumbered by control animals. In July, these differences reached statistically significant values: 4,085 ± 71 g vs. 3,736 ± 73 g (p < 0.01). Thus, the marmots of the experimental group recovered faster after winter hibernation

Оптимизация технологии получения препарата бактерий человека для биологической коррекции микрофлоры кишечника

Fecal microbiota transplantation (FMT) is now considered as an effective tool for the treatment of various GI pathologies. Fecal preparations are delivered both through the lower GIT (enema, colonoscopy) and upper (endoscopy, capsules). A common disadvantage of instrumental methods of administration is their high invasiveness associated with the risk of intestinal perforation and the use of anesthesia. Oral capsules are minimally invasive, comfortable and more aesthetic, so this method of drug delivery is gaining popularity. The main issue with the use of frozen feces (including the lyophilisate used in capsules) is its efficiency compared to the original material. During lyophilization, cells are exposed to stress factors such as low temperatures, water crystallization, osmotic stress, changes in pH, and dehydration. To reduce the likelihood of cell damage during lyophilization, protective media (lyo-protectants) are used. In this work sucrose, gelatin, and their combinations have been used as lyoprotectors. To estimate the number of microorganisms, a bacteriological study was carried out. The number of Bifidobacteria, Lactobacilli, and the total number of E.coli and Enterobacteriaceae was estimated. It was found that the lyophilized stool sample containing 10% sucrose as a protective medium had the highest number of viable cells. Also, the physical properties of the lyophilisate (its flowability) are convenient for preparing capsulated form. The molar ratios of short chain fatty acids (SCFAs) in the original fecal samples and lyophilisates were studied by gas chromatography. The molar ratios of major SCFAs (acetate, propionate and butyrate) were identical in the samples studied. The composition of the protective medium in which the lyophilized biomaterial corresponds to the original feces in terms of the number of "live" microorganisms has been proposed. According to its physical characteristics lyophilisate is convenient for capsules preparation.К настоящему моменту эффективность трансплантации фекальной микробиоты (ТФМ) при лечении различных патологий ЖКТ не вызывает сомнений. Препараты фекалий доставляют как через нижние отделы ЖКТ (клизма, колоноскопия), так и верхние (эндоскопия, капсулы). Общим недостатком инструментальных методов введения является их высокая инвазивность, связанная с риском перфорации кишечника и применением анестезии. Пероральные капсулы минимально инвазивны, удобны и более эстетичны, поэтому этот способ доставки препарата становится все более популярным. Основной вопрос, связанный с использованием замороженного кала (в том числе лиофилизата, используемого в капсулах), заключается в эффективности такого препарата по сравнению с исходным материалом. В процессе лиофилизации клетки подвергаются действию стрессовых факторов, таких как низкие температуры, кристаллизация воды, осмотический стресс, изменения рН растворов, дегидратация. Для снижения риска повреждений клеток при лиофилизации используют защитные среды (лиопротекторы). В качестве лиопротекторов в данной работе использовали сахарозу, желатин и их комбинации. Для оценки количества микроорганизмов проводили бактериологическое исследование. Оценивали количество бактерий рода Bifidobacterium, Lactobacillus, Escherichia, а также семейства Enterobacterales в целом. Установлено, что в лиофилизированном образце кала, содержащем в качестве защитной среды 10 % сахарозу, наблюдается наибольшее количество жизнеспособных клеток, физические свойства лиофилизата (его сыпучесть) удобны для наполнения капсул. Методом газовой хроматографии исследованы молярные соотношения КЖК в исходных образцах кала и лиофилизатах. Молярные соотношения мажорных короткоцепочечных жирных кислот (КЖК) ацетата, пропионата и бутирата оказались идентичны в исследуемых образцах. Предложен состав защитной среды, в которой лиофилизированный биоматериал максимально соответствует исходному калу по количеству «живых» микроорганизмов. Лиофилизат по своим физическим характеристикам удобен для приготовления капсул

Growth, reproduction and feeding of the tropical squid Ornithoteuthis antillarum (Cephalopoda, Ommastrephidae) from the central-east Atlantic

Length composition, age, growth, reproductive biology, feeding and parasites were studied using 432 individuals of the squid Ornithoteuthis antillarum (1.8-138 mm ML) collected in the open waters of the tropical central-east Atlantic. In the region studied, only a small-sized and early-maturing population of O. antillarum occur. Statolith shape, development and microstructure have several peculiar features setting O. antillarum apart of other ommastrephids. Assuming growth increments within statoliths to be daily, maximum age of squids does not exceed 182 days. Growth rates of juveniles and immature squids are high and similar to another fast-growing ommastrephid Sthenoteuthis pteropus, but they decrease considerably with the onset of maturation. Potential fecundity varies from 50,000 to 220,000 oocytes. It is suggested that the squid is a multiple spawner with frequent releases of small-sized (No disponibl

Effects of Melatonin-aided therapy on the Glutathione antioxidant system activity and liver protection

Acute hepatitis results from oxidative stress triggered by hepatotoxic drugs causing liver injury and the activation of caspases cascade. The glutathione antioxidant system protects against reactive oxygen species and mitigates development of these processes. The effectiveness of silymarin, a polyphenolic flavonoid, essenthiale, composed of phosphatidyl choline, and melaxen, a melatonin-correcting drug, as hepatoprotectors has been investigated. The variation of 6-sulfatoxymelatonin (aMT6s), resulting from the biotransformation of melatonin, and GSH has been measured. The activities of caspase-1 and caspase-3, glutathione antioxidant system, and NADPH-generating enzymes were determined. The aMT6s decreases in patients with drug hepatitis and recovers with administration of mexalen. GSH increased in the presence of the studied hepatoprotectors. Pathologically activated caspase-1 and caspase-3 decreased their activities in the presence of hepatoprotectors with melaxen showing the highest effect. The positive effect of melatonin appears to be related to the suppression of decompensation of the glutathione antioxidant system functions, recovery of liver redox status, and the attenuation of inhibition of the NADPH supply.This work was supported by grant of the President of the Russian Federation for young scientists MK- 3133.2011.7. Authors thank to President of Voronezh State Medical Academy named after N. N. Burdenko (Russia), Prof. Igor E. Esaulenko, for advice and suggestions.info:eu-repo/semantics/publishedVersio

Guiding superconducting vortices by magnetic domain walls

We demonstrate a unique prospect for inducing anisotropic vortex pinning and manipulating the directional motion of vortices using the stripe domain patterns of a uniaxial magnetic film in a the superconducting/ferromagnetic hybrid. Our observations can be described by a model, which considers interactions between magnetic charges of vortices and surface magnetic charges of domains resulting in the enhanced pinning of vortices on domain walls.Comment: 12 pages, 6 figure

Fecal microbiota transplantation in the treatment of astrovirus infection in a recipient of an allogeneic hematopoietic stem cell transplant: a clinical case

Background: Secondary immunodeficiency in recipients after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the pediatric practice is often accompanied by bacterial and viral infections of the gastrointestinal tract (GIT), resistant to conventional therapy. Fecal microbiota transplantation (FMT) promotes intestinal recolonization and eradication of gastrointestinal symptoms. Clinical case description: A 2.5-year-old patient underwent allo-HSCT from a haploidentical related donor (father) as a part of the treatment of acute myeloid leukemia. A month after the last procedure, diarrhea (up to 10 times a day) and abdominal pain appeared. The astrovirus RNA and Clostridium difficile toxin A were detected in the feces. The FMT was prescribed. After two FMT procedures, the intestinal syndrome leveled out, and the tests for the astrovirus RNA and clostridial toxins were negative. The content of cholic and, in particular, deoxycholic acids, as well as their conjugates with glycine and taurine, in the feces increased; the acetic acid content increased with a simultaneous decrease in the level of propionic acid, which indicates the restoration of the intestinal microbiotas functional potential. Conclusion: FMT contributes to the restoration of the normal intestinal microflora, the elimination of clostridial toxins, enteroinvasive E. coli and astrovirus infection in allo-HSCT recipients, as evidenced by the indicators of the intestinal microbiota activity, and can be used in allo-HSCT recipients with infections refractory to conventional therapy

A fluorescent microspheres-based microfluidic test system for the detection of immunoglobulin G to SARS-CoV-2

Background: The pandemic of the new coronavirus infection, COVID-19, is currently ongoing in the world. Over the years, the pathogen, SARS-CoV-2, has undergone a series of mutational genome changes, which has led to the spread of various genetic variants of the virus. Meanwhile, the methods used to diagnose SARS-CoV-2, to establish the disease stage and to assess the immunity, are nonspecific to SARS-CoV-2 variants and time-consumable. Thus, the development of new methods for diagnosing COVID-19, as well as their implementation in practice, is currently an important direction. In particular, application of systems based on chemically modified fluorescent microspheres (with a multiplex assay for target protein molecules) opens great opportunities. Aim: development of a microfluidic diagnostic test system based on fluorescent microspheres for the specific detection of immunoglobulins G (IgG) to SARS-CoV-2. Methods: A collection of human serum samples was characterized using enzyme-linked immunosorbent assay (ELISA) and commercially available reagent kits. IgG to SARS-CoV-2 in the human serum were detected by the developed immunofluorescent method using microspheres containing the chemically immobilized RBD fragment of the SARS-CoV-2 (Kappa variant) viral S-protein. Results: The level of IgG in the blood serum of recovered volunteers was 9-300 times higher than that in apparently healthy volunteers, according to ELISA (p0.001). Conjugates of fluorescent microspheres with the RBD-fragment of the S-protein, capable of specifically binding IgG from the blood serum, have been obtained. The immune complexes formation was confirmed by the fluorescence microscopy data; the fluorescence intensity of secondary antibodies in the immune complexes formed on the surface of microspheres was proportional to the content of IgG (r 0.963). The test system had a good predictive value (AUC 70.3%). Conclusion: A test system has been developed, based on fluorescent microspheres containing the immobilized RBD fragment of the SARS-CoV-2 S-protein, for the immunofluorescent detection of IgG in the human blood serum. When testing the system on samples with different levels of IgG to SARS-CoV-2, its prognostic value was shown. The obtained results allow us to present the test system as a method to assess the level of immunoglobulins to SARS-CoV-2 in the human blood serum for the implementation in clinical practice. The test system can also be integrated into various microfluidic systems to create chips and devices for the point-of-care diagnostics