Shape critical properties of patterned Permalloy thin films.

The effects of shape and edges in magnetic elements with reduced dimensions on the magnetization reversal of cross- and framed cross-shaped Ni79Fe21 (30nm) films were studied. Remagnetization details in the stripes of the patterned structures, which had 3 µm to 30 µm widths and ~100 µm lengths, were visualized by the magneto-optical indicator film technique. The magneto-optic images revealed three different types of the domain structure formation and evolution in the samples during their magnetization reversal: (i) spin rotation with growth and annihilation of a cross-tie structure in the stripes perpendicular to the applied field, (ii) nucleation and fast motion of special boundaries, which consist of a number of coupled vortices located along both edges of the stripes parallel to the applied field, and (iii) nonuniform magnetization rotation with macrodomain nucleation and domain wall motion in the large unpatterned part of the films. It was experimentally revealed that there exists a dependence of the critical field for nucleation and motion of domain walls in the parallel-to-field stripes on their width and frame width. In particular, an inverse proportionality between this nucleation field and stripe width was found. Both experimental and simulation results show that, in cases (i) and (ii), the magnetostatic fields, which are formed on the edges of the stripes and at their intersections, play a crucial role in the formation of spin inhomogeneities and switching of the samples.

Bacterial translocation from the gastrointestinal tract in healthy and injured rats.

OBJECTIVE: To study the phenomenon of asymptomatic penetration of bacteria from the gastrointestinal tract into various tissues of healthy rats and rats with skin wounds and closed fractures at different doses and with different species of bacteria. METHOD: Healthy rats and rats with full-thickness skin wounds and closed femoral fractures were given varying doses of radiolabeled bacteria (S. aureus 209P or B. subtilis 534) per os in doses of up to 1010 bacteria per 1kg of body mass. Six hours later, these animals were euthanised and, together with blood smears, tissue samples of liver, spleen, stomach, small and large intestine, lung, hypothalamus, posterior pituitary gland, epinephros and skin and muscle from the wound site were subjected to bacteriological and histological analysis. RESULTS: In total, 99 rats were used for the experiments. Viable bacteria were found to systemically penetrate into the tissues of the internal organs in 45 healthy animals, 27 rats with incisions and 27 rats with fractures. In healthy animals, viable bacteria mostly accumulated in the stomach wall, the mucous membranes of the small intestine, the mesenteric lymph nodes and in the spleen and liver. Translocation was registered in uninjured animals receiving 1x106 and more bacteria per 1kg of rat's weight and in injured rats receiving 1x104 bacteria and more. Bacteria penetrated the local tissues at both wound sites (skin wounds and fracture sites). CONCLUSION: Bacterial translocation is a protective mechanism that gives the immune system constant contact with external antigens, although it can contribute to the spreading of infection in an organism. In healthy animals, small amounts of bacteria penetrate systemically from the tract and small intestine into the tissues of the spleen and liver. During injury, translocated bacteria also appear at the focus of injury. CONFLICT OF INTEREST: None.

[Sporobakterin impact on atherogenic dyslipidemia at patients with intestinal dysbacteriosis].

UNLABELLED: The aim was to evaluate the correlation of intestinal microflora with indicators of lipid metabolism and the possibility of its correcting with sporobakterin. MATERIAL AND METHODS: 38 patients from gastroenterological department (men - 18 women - 20, average age - 54,00 +/- 13,59 years), trapped in a random 5% sample. Were assessed the state of the luminal microflora in the large intestine and total cholesterol, b-lipoprotein (b-PL) and HDL in serum levels. Fence, preparation and sowing of faeces were carried out according to the methodical recommendations of N. M. Gracheva et al. (1986). Counting and smear from the colonies of one species were made after a day of incubation. Lipid fraction of serum was evaluated on biochemical analyzer Cobas Integra 400 (Roche, Switzerland). 15 patients with intestinal disorders of microbiocenosis and hypercholesterolemia, was conducted drug treatment with "Sporobakterin liquid, a suspension for oral use" (OOO "Bacor", Russia) for a recommended scheme. Were assessed serum levels of total cholesterol, HDL, and beta-LP, composition of intestinal microflora, the body mass before and after treatment. Statistical analysis was conducted using methods of variation statistics. RESULTS: it was revealed a positive effect of the sporobakterin on intestinal microflora and statistically significant reduction in total cholesterol and b-LP, a tendency to body weight reduce. CONCLUSION: The results indicated the influence of intestinal microflora on the atherogenic fractions of serum and the possibility of their correction with a sporobakterin.

Asymmetric domain nucleation and unusual magnetization reversal in ultrathin Co films with perpendicular anisotropy.

We report unexpected phenomena during magnetization reversal in ultrathin Co films and Co/Pt multilayers with perpendicular anisotropy. Using magneto-optical Kerr microscopy and magnetic force microscopy we have observed asymmetrical nucleation centers where the reversal begins for one direction of the field only and is characterized by an acute asymmetry of domain-wall mobility. We have also observed magnetic domains with a continuously varying average magnetization, which can be explained in terms of the coexistence of three magnetic phases: up, down, and striped.

Antisymmetric magnetoresistance in magnetic multilayers with perpendicular anisotropy.

While magnetoresistance (MR) has generally been found to be symmetric in applied field in nonmagnetic or magnetic metals, we have observed antisymmetric MR in Co/Pt multilayers. Simultaneous domain imaging and transport measurements show that the antisymmetric MR is due to the appearance of domain walls that run perpendicular to both the magnetization and the current, a geometry existing only in materials with perpendicular magnetic anisotropy. As a result, the extraordinary Hall effect gives rise to circulating currents in the vicinity of the domain walls that contributes to the MR. The antisymmetric MR and extraordinary Hall effect have been quantitatively accounted for by a theoretical model.

Infection prophylaxis of gunshot wounds using probiotics.

OBJECTIVE: To report a new method of surgical infection prophylaxis for postoperative gunshot wounds to the extremities. METHOD: Gunshot wounded animals were divided into three groups: treatment (probiotic Sporobacterin), antibiotic (cephalosporin cefamezin) and control (no treatment). Histological studies of wound-bed tissue were taken on days 1, 3, 5 and 10 of the study. RESULTS: The probiotic administered per os was more effective than antibiotics for prophylaxis of surgical infection. CONCLUSION: The probiotic's effect is based on the natural defence mechanism activated after injury--the bacterial translocation of saprophytic bacteria from the gut to the wound. DECLARATION OF INTEREST: None.

[Experimental-clinical basis for using sporobacterin in the combined treatment of pancreonecrosis]. / Eksperimental'no-klinicheskoe obosnovanie primeneniia sporobakterina v kompleksnom lechenii pankreonekroza.

Experimental investigations on translocation of the intestinal microflora on the model of acute pancreatitis were performed in 54 animals (albino rats) and showed an increased bacterial dissemination of parenchymatous organs of the abdominal cavity as the inflammatory and destructive alterations increased in the pancreas. E. coli aggravated the inflammatory alterations in the pancreas while B. subtilis promoted reparative processes. Experimental substantiation is given to using sporobacterin in the complex postoperative treatment of patients with pancreatonecrosis.

Direct magneto-optical observation of a structural phase transition in thin films of manganites.

The spontaneous formation of twins in La(2/3)Ca(1/3)MnO3 films below T(S) approximately 105 K is observed by a magneto-optical technique. The twins are revealed as stripes along the {110} directions where magnetization tilts out of the film plane due to the stresses in twins. Their appearance is associated with a martensitic phase transition in the film triggered by the cubic-to-tetragonal transition in the SrTiO3 substrate. It is found that magnetization of the films proceeds by inhomogeneous rotation of magnetic moments. This is due to the presence of microscopic structural inhomogeneities. Their dominating role in the low-temperature transport can explain small effects of the transition at T(S) on the resistivity.

Asymmetry in elementary events of magnetization reversal in a ferromagnetic/antiferromagnetic bilayer.

Real-time magneto-optical indicator film images reveal distinct asymmetry in the motion of a single domain wall in a wedged-NiFe/uniform-FeMn bilayer due to the nucleation and behavior of an exchange spring in the antiferromagnetic layer. Magnetization reversal from the ground state begins at the thick end of the wedge where the exchange anisotropy field (HE) is minimal and the magnetostatic field (HMS) is maximal, whereas reversal into the ground state begins from the thin end where HE is maximal and HMS is minimal.

[Role of dysbacteriosis in the development of surgical infection]. / O roli disbakterioza v razvitii khirurgicheskoi infektsii.

The intestinal microflora was examined in 230 patients operated on for abdominal abnormalities and injuries. There were profound intestinal microbiocenotic impairments as appeared as lower bifidobacteria, intensive growth of opportunistic (coccal) microorganisms. A direct relationship was established between the severity of dysbacteriosis and the incidence of pyoinflammatory complications in the postoperative period. The use of live bacterial preparations in the complex therapy of patients with expected and emergency abdominal diseases or injuries reduced the number of pyoinflammatory complications and improved the therapeutic outcomes of patients with peritonitis.

[Interrelations between macroorganisms and bacteria in wounds and tissues of humans and animals]. / Vzaimootnosheniia makroorganizma i bakterii v rane i tkaniakh cheloveka i zhivotnykh.

It is shown that bacteria from the gastrointestinal tract penetrate systematically into the tissues of the focus of damage in man and animals in the blood and lymph. It was found that certain bacterial species maintain vitality in tissues, in which they do not induce pathological reactions but may produce a therapeutic effect due to the production of antibiotics, proteolytic enzymes, immunomodulators, etc. The author describes the results of experimental and clinical study of Sporobacterin, a new agent, intended for the prevention and treatment of surgical infection.