Probiotic Potential, Safety Properties, and Antifungal Activities of Corynebacterium amycolatum ICIS 9 and Corynebacterium amycolatum ICIS 53 Strains.

The purpose of this study was to evaluate the probiotic characteristics and safety and to study the antifungal activity of C. amycolatum ICIS 9 and C. amycolatum ICIS 53 against Candida spp. The probiotic potential and safety properties were assessed by standard parameters. Both strains showed good survival at pH 3 for 3 h and high tolerance to 0.3% bile salts after 4 h of incubation. The indicators of hydrophobicity, autoaggregation, and surface tension for ICIS 9 were 89.43% (n-hexane) and 73.96% (xylene) and ranged from 13.13 to 39.86% and 34.27 mN/m, respectively. For ICIS 53, they were 59.95% (n-hexane) and 45.68% (xylene), from 35.58 to 51.53% and 32.40 mN/m, respectively. The strains ICIS 9 and ICIS 53 exhibited varying levels of coaggregation with all eight examined bacterial pathogens. The ICIS 9 strain was resistant to amikacin, amoxicillin, clarithromycin, chloramphenicol, ciprofloxacin, and gentamycin. ICIS 53 was resistant only to ciprofloxacin. The cell-free supernatant of strains ICIS 9 and ICIS 53 showed good antimicrobial and antibiofilm activity against 10 pathogenic vaginal and intestinal isolates of Candida spp. The CFS of ICIS 9 was more active against intestinal isolates, and the CFS of ICIS 53 showed good antimicrobial activity against vaginal isolates while inhibiting the growth of 2 out of 5 Candida spp. isolated from the intestine. Both of the strains were capable of reducing the biofilm formation of Candida fungi. In the case of the vaginal isolates of C. krusei V1, the results showed that the inhibition levels of ICIS 9 and ICIS 53 were 36.75 and 11.4%, respectively. In the case of C. albicans (V2, V3, V7, and V8), the inhibition of biofilm formation was no more than 7.07%. ICIS 9 and ICIS 53 also significantly inhibited biofilm formation of C. krusei 2613 intestinal isolates by 42.75 and 41.87%, respectively, with ICIS 9 inhibiting biofilm formation of C. albicans (2607, 2311, 2615, and 2615) from 3.38 to 15.69% and ICIS 53 from 5.95 to 23.48%. None of the strains showed DNase, haemolytic, or gelatinase activities. The results obtained revealed that ICIS 9 and ICIS 53 have safe properties and have the potential to be developed as probiotics.

Genome Analysis of the Probiotic Strain Enterococcus faecium Ef79OSAU.

We report here the draft genome sequence of Enterococcus faecium strain Ef79OSAU, which was isolated from swine feces. The characteristics of strain Ef79OSAU reveal the absence of pathogenicity factors, a wide range of antimicrobial activity in vitro, and antilisteriosis activity in vivo. Analysis of the E. faecium Ef79OSAU genome revealed a cluster of genes encoding enterocin A without genetic determinants of pathogenicity.

Effects of a New Benzimidazole Derivative with Actoprotective Properties on Spermatogenic Epithelium of the Testes and Fertility of Male White Rats.

The effects of a new derivative of benzimidazole (K-134) in doses of 5 and 50 mg/kg on the spermatogenesis and fertilizing ability of spermatozoa were studied on male rats. It was found that 2-month course treatment with the studied substance enhances the producing ability of the spermatogenic epithelium and improves fertilizing ability of spermatozoa.

Prediction and observation of an antiferromagnetic topological insulator.

Magnetic topological insulators are narrow-gap semiconductor materials that combine non-trivial band topology and magnetic order1. Unlike their nonmagnetic counterparts, magnetic topological insulators may have some of the surfaces gapped, which enables a number of exotic phenomena that have potential applications in spintronics1, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3. So far, magnetic topological insulators have only been created by means of doping nonmagnetic topological insulators with 3d transition-metal elements; however, such an approach leads to strongly inhomogeneous magnetic4 and electronic5 properties of these materials, restricting the observation of important effects to very low temperatures2,3. An intrinsic magnetic topological insulator-a stoichiometric well ordered magnetic compound-could be an ideal solution to these problems, but no such material has been observed so far. Here we predict by ab initio calculations and further confirm using various experimental techniques the realization of an antiferromagnetic topological insulator in the layered van der Waals compound MnBi2Te4. The antiferromagnetic ordering  that MnBi2Te4  shows makes it invariant with respect to the combination of the time-reversal and primitive-lattice translation symmetries, giving rise to a ℤ2 topological classification; ℤ2 = 1 for MnBi2Te4, confirming its topologically nontrivial nature. Our experiments indicate that the symmetry-breaking (0001) surface of MnBi2Te4 exhibits a large bandgap in the topological surface state. We expect this property to eventually enable the observation of a number of fundamental phenomena, among them quantized magnetoelectric coupling6-8 and axion electrodynamics9,10. Other exotic phenomena could become accessible at much higher temperatures than those reached so far, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3.

[Influence of the dense extract from herb of Primula veris L. On the oxidative stress development and the functional state of the cardiomyocytes mitochondria of rats with experimental chronic heart failure]. / Vliianie gustogo ékstrakta iz travy pervotsveta vesennego na razvitie oksidativnogo stressa i funktsional'noe sostoianie mitokhondrii kardiomiotsitov krys s éksperimental'noi khronicheskoi serdechnoi nedostatochnost'iu.

Experimental chronic heart failure (CHF), caused by administration of L-isoproterenol (2.5 mg/kg twice a day intraperitoneally for 21 days), promotes uncoupling of respiration and oxidative phosphorylation. The rate of mitochondrial oxygen consumption in the metabolic state V3 by Chance in animals with CHF decreased by 53.3% (p<0.05) with malate using (as an oxidation substrate feeding сomplex I of the electron transport chain (ETC)), by 70.6% (p<0.05) with succinate using (сomplex II substrate) and by 63.6% (p<0.05) when malate and succinate were added simultaneously. The respiratory control ratio significantly decreased 2.3 times for сomplex I, 2.5 for сomplex II, and 2.6 times for the simultaneous operation of two respiratory chain complexes in mitochondria of CHF rats compared to intact animals. Mitochondrial dysfunction in experimental CHF is evidently due to the development of oxidative stress. It was revealed that the content of malonic dialdehyde (MDA) in the group of rats with experimental CHF was higher by 54.7% (p<0.05), as compared with intact animals. The activity of superoxide dismutase (SOD) and catalase was lower by 17.5% (p<0.05), and by 18.4%, respectively than in the intact group. The dense extract from herba of Primula veris L. (DEHPV) 30 mg/kg limits the development of mitochondrial dysfunction in rats with experimental CHF, as evidenced by an increase in the role of V3 respiration for the first and second respiratory chain complexes in 1.7 (p<0.05) and 2.0 times (p<0.05), respectively, the ratio of respiratory control (RCR) - 1.7 times (p<0.05) for сomplex I and 2 times (p<0.05) for сomplex II compared with the negative control. The concentration of MDA was by 15.7% (p<0.05), lower and the activity of SOD was by 56.3% (p<0.05) higher.

Unraveling the Nature of Magnetism of the 5d

We report electron spin resonance (ESR) spectroscopy results on the double perovskite Ba_{2}YIrO_{6}. On general grounds, this material is expected to be nonmagnetic due to the strong coupling of the spin and orbital momenta of Ir^{5+} (5d^{4}) ions. However, controversial experimental reports on either strong antiferromagnetism with static order at low temperatures or just a weakly paramagnetic behavior have triggered a discussion on the breakdown of the generally accepted scenario of the strongly spin-orbit coupled ground states in the 5d^{4} iridates and the emergence of a novel exotic magnetic state. Our data evidence that the magnetism of the studied material is solely due to a few percent of Ir^{4+} and Ir^{6+} magnetic defects while the regular Ir^{5+} sites remain nonmagnetic. Remarkably, the defect Ir^{6+} species manifest magnetic correlations in the ESR spectra at T≲20 K, suggesting a long-range character of superexchange in the double perovskites as proposed by recent theories.

Magneto-structural correlations in oxalate-bridged Sr(ii)Cr(iii) coordination polymers: structure, magnetization, X-band, and high-field ESR studies.

The results of high-field electron spin resonance (HF-ESR) spectroscopy on the title 1D coordination polymers at frequencies up to 415 GHz, supported by X-ray diffraction, thermal, magnetic susceptibility, and X-band (10 GHz) ESR studies, are presented. The heterometallic compounds {SrCr2(phen)2(C2O4)4}·H2O (SrCrPhen) and {SrCr2(bpy)2(C2O4)4(H2O)}·5H2O (SrCrBpy) (phen = 1,10-phenanthroline, bpy = 2,2'-bipyridine) were synthesized. Structural analysis revealed double oxalate-bridged zigzag Sr-Cr chains while magnetic susceptibility studies showed paramagnetic behaviour of the complexes. HF-ESR spectroscopy data were analysed with a relevant spin-Hamiltonian, yielding the g, D and E parameters of the Cr(iii) ions. Both complexes showed small magnetic easy-axis type anisotropy with |D| ∼ 1 K; SrCrBpy has uniaxial anisotropy while SrCrPhen has biaxial anisotropy. HF-ESR studies have enabled us to establish rational magneto-structural correlations and revealed significant differences between very similar crystal structures. Additionally, the ability of SrCrPhen and SrCrBpy to be single-source precursors for the formation of Sr-Cr oxides was investigated.

Signatures of a magnetic field-induced unconventional nematic liquid in the frustrated and anisotropic spin-chain cuprate LiCuSbO4.

Modern theories of quantum magnetism predict exotic multipolar states in weakly interacting strongly frustrated spin-1/2 Heisenberg chains with ferromagnetic nearest neighbor (NN) inchain exchange in high magnetic fields. Experimentally these states remained elusive so far. Here we report strong indications of a magnetic field-induced nematic liquid arising above a field of ~13 T in the edge-sharing chain cuprate LiSbCuO4 ≡ LiCuSbO4. This interpretation is based on the observation of a field induced spin-gap in the measurements of the 7Li NMR spin relaxation rate T 1-1 as well as a contrasting field-dependent power-law behavior of T 1-1 vs. T and is further supported by static magnetization and ESR data. An underlying theoretical microscopic approach favoring a nematic scenario is based essentially on the NN XYZ exchange anisotropy within a model for frustrated spin-1/2 chains and is investigated by the DMRG technique. The employed exchange parameters are justified qualitatively by electronic structure calculations for LiCuSbO4.

Effects of a New Benzimidazole Derivative on Generative Function of Female Rats.

The effects of a new thietanylbenzimidazole derivative (K-134) on estrous cycles, conception processes, and sexual behavior of female rats were studied. Two-week oral treatment with K-134 in doses of 5 and 50 mg/kg shortened the estrus phase and prolonged proestrus. Changes in sexual behavior were presented by activation of receptive sexual motivations without affecting proceptive motivations. The pregnancy and fertility indexes in experimental females after mating with intact males increased and pre- and postimplantation embryonic death decreased.

[Synthesis, isomery, and hypotensive activity of thiethane-containing ylidenehydrazides of uracilylacetic acid].

Using reaction of hydrazide 2-[6-methyl-1-(thiethane3-yl)uracil-3-yl]acetic acid with arylaldehydes and acetophenone derivatives were obtained acylhydrazones, which exist in DMSO solution as a mixture of two stereoisomers of a E(C=N)-isomer for due to hindered internal rotation around the hydrazide bond. It was revealed that the synthesized compounds exhibit antihypertensive activity.

Flux dynamics and avalanches in the 122 pnictide superconductor Ba0.65Na0.35Fe2As2.

In this work we present the results of the bulk magnetization measurements in a superconducting state of single crystals of Ba0.65Na0.35Fe2As2. The isothermal magnetic field (H âˆ¥ c axis) dependent magnetization (M) loops exhibit a second peak (SP) or 'fishtail effect', as well as remarkable flux jumps at low temperatures. The critical current density Jc obtained from the M(H) loops is rather high, of the order of 10(6) A cm(-2). The analysis of the temperature- and field-dependent Jc implies that high Jc is mainly due to collective (weak) pinning of vortices by dense microscopic point defects with some contribution from a strong pinning mechanism. Pronounced magnetic instabilities in terms of flux jumps depend strongly on temperature as well as on the field sweep rate. The field for the first flux jump as calculated from an adiabatic model, however, is much lower than the experimentally observed values, and this enhanced stability is attributed to a flux creep phenomenon. The analysis of field-dependent magnetic relaxation data additionally supports a collective pinning model. The data further suggest that SP in M(H) is likely related to the crossover in creep dynamics from an elastic to a plastic mechanism. We have constructed the vortex phase diagram on the field-temperature plane.

Slow magnetic relaxations in manganese(III) tetra(meta-fluorophenyl)porphyrin-tetracyanoethenide. Comparison with the relative single chain magnet ortho compound.

Mn(III) tetra(meta-fluorophenyl)porphyrin-tetracyanoethenide coordination polymer (abbreviated meta-F) was synthesized and crystallographically and magnetically characterized. The compound crystallizes in the space group C2/c with four equivalent molecules in the unit cell arranged along two symmetry related nonparallel linear chain directions. Magnetic properties were studied by SQUID dc magnetization and ac susceptibility techniques and high field-high frequency electron spin resonance (HF-ESR). Glassy transition to a ferromagnetic-like state is observed at 10 K accompanied by slow magnetic relaxations. The glassiness is interpreted as due to 3D domain wall pinning. In a bias dc magnetic field the width of the relaxation time distribution decreases and the relaxations become similar to the relaxations of the single chain magnet Mn(III) tetra(ortho-fluorophenyl)porphyrin-tetracyanoethenide (abbreviated ortho-F), for which comparative HF-ESR studies were also conducted in this work. Magnetic properties of these two compounds are compared, and the nature of magnetic relaxations in meta-F is discussed.

Evidence for triplet superconductivity in a superconductor-ferromagnet spin valve.

We have studied the dependence of the superconducting (SC) transition temperature on the mutual orientation of magnetizations of Fe1 and Fe2 layers in the spin valve system CoO(x)/Fe1/Cu/Fe2/Pb. We find that this dependence is nonmonotonic when passing from the parallel to the antiparallel case and reveals a distinct minimum near the orthogonal configuration. The analysis of the data in the framework of the SC triplet spin valve theory gives direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the two magnetizations.

[Synthesis and antituberculosis activity of the derivatives of glycoside steviolbioside from the plant Stevia rebaudiana and diterpenoid isosteviol containing hydrazone, hydrazide and pyridinoyl moieties].

Conjugates of antitubercular drug Isoniazid (hydrazide of isonicotinic acid), nicotinic and alpha-picolinic acid hydrazides and glycoside steviolbioside from the plant Stevia rebaudiana as well as the product of its acid hydrolysis, diterpenoid isosteviol, were synthesized. Besides, isosteviol hydrazide and hydrazone derivatives as well as conjugates containing two isosteviol moieties connected by dihydrazide linker were also obtained. Both initial compounds and their synthetic derivatives inhibit the growth of Mycobacterium tuberculosis (H37Rv in vitro). The minimum concentration at which the growth of M. tuberculosis was inhibited by 100% (MIC) for stevioside and steviolbioside equals 7.5 and 3.8 microg/mL, respectively. MIC values for conjugates of the hydrazides of pyridine carbonic acids and steviolbioside as well as isosteviol are in the ranges 5-10 and 10-20 microg/mL, respectively. Maximum inhibitory effect against M. tuberculosis showed the conjugates of isosteviol and adipic acid dihydrazide (MIC values ranged from 1.7 to 3.1 microg/mL). Antitubercular activity of the compounds studied is higher than the activity of antitubercular drug Pyrizanamide (MIC = 12.5-20 microg/mL) but lower than the activity of antitubercular drug Isoniazid (MIC = 0.02-0.04 microg/mL).

First direct in situ EPR spectroelectrochemical evidence of the superoxide anion radical.

For the first time, the superoxide anion radical was formed by electrochemical reduction of oxygen and detected in situ by EPR spectroscopy without changing the temperature. The spin susceptibilities of solid superoxide solutions were measured between 280 and 4 K showing Curie behavior. The EPR results were explained in the frame of an ion association and support the formation of a loose ion pair between the superoxide anion radical and the potassium crown ether complex. An alternative explanation for the large EPR line width of the superoxide anion radical at higher temperatures is given.

Spin gap in the zigzag spin-1/2 chain cuprate Sr(0.9)Ca(0.1)CuO(2).

We report a comparative study of (63)Cu nuclear magnetic resonance spin lattice relaxation rates T(1)(-1) on undoped SrCuO(2) and Ca-doped Sr(0.9)Ca(0.1)CuO(2) spin chain compounds. A temperature independent T(1)(-1) is observed for SrCuO(2) as expected for an S=1/2 Heisenberg chain. Surprisingly, we observe an exponential decrease of T(1)(-1) for T<90 K in the Ca-doped sample evidencing the opening of a spin gap. The data analysis within the J(1)-J(2) Heisenberg model employing density-matrix renormalization group calculations suggests an impurity driven small alternation of the J(2)-exchange coupling as a possible cause of the spin gap.

Manifestation of new interference effects in a superconductor-ferromagnet spin valve.

Superconductor-ferromagnet (S/F) spin valve effect theories based on the S/F proximity phenomenon assume that the superconducting transition temperature Tc of F1/F2/S or F1/S/F2 trilayers for parallel magnetizations of the F1 and F2 layers (T(c)(P)) are smaller than for the antiparallel orientations (T(c)(AP)). Here, we report for CoOx/Fe1/Cu/Fe2/In multilayers with varying Fe2-layer thickness the sign-changing oscillating behavior of the spin valve effect ΔT(c) = T(c)(AP) - T(c)(P). We observe the full direct effect with T(c)(AP) > T(c)(P) for Fe2-layer thickness d(Fe2) < 1 nm and the full inverse (T(c)(AP) < T(c((P)) effect for d(Fe2) ≥ 1 nm. Interference of Cooper pair wave functions reflected from both surfaces of the Fe2 layer appear as the most probable reason for the observed behavior of ΔT(c).

[Synthesis and modification of triterpenoids with two lupan backbones].

The first derivatives containing two lupan backbones were synthesized by the interaction of betulonic acid chloride with diols (ethylene glycol and diethylene glycol) and monoethanolamine. A modification of ring A of ethylene-l,2-bis(betulonnate) led to its bis(3beta-aminopropyloxy) and bis(3,4-seco-2-cyano) derivatives.

Evolution of the Kondo state of YbRh2Si2 probed by high-field ESR.

An electron spin resonance (ESR) study of the heavy fermion compound YbRh2Si2 for fields up to approximately 8 T reveals a strongly anisotropic signal in the Kondo state below approximately 25 K. A similarity between the T dependence of the ESR parameters and that of the specific heat and the 29Si nuclear magnetic resonance data gives evidence that the ESR response is given by heavy fermions. Tuning the Kondo effect on the 4f states with magnetic fields approximately 2-8 T and temperature 2-25 K yields a gradual change of the ESR g factor and linewidth which reflects the evolution of the Kondo state in this Kondo lattice system.

Spin-state polarons in lightly-hole-doped LaCoO3.

Inelastic neutron scattering (INS), electron spin resonance (ESR), and nuclear magnetic resonance (NMR) measurements were employed to establish the origin of the strong magnetic signal in lightly-hole-doped La1-xSrxCoO3, x approximately 0.002. Both INS and ESR low temperature spectra show intense excitations with large effective g factors approximately 10-18. NMR data indicate the creation of extended magnetic clusters. From the Q dependence of the INS magnetic intensity, we conclude that the observed anomalies are caused by the formation of octahedrally shaped spin-state polarons comprising seven Co ions. The present INS, ESR, and NMR data give evidence for two regimes in the lightly-hole-doped samples: (i) T<35 K dominated by spin polarons; (ii) T>35 K dominated by thermally activated magnetic Co3+ ions.