Field-induced magnetic anisotropy in La0.7Sr0.3CoO3

Magnetic anisotropy has been measured for the ferromagnetic La0.7Sr0.3CoO3 perovskite from an analysis of the high-field part of the magnetization vs. field curves, i.e., the magnetic saturation regime. These measurements give a magnetic anistropy one order of magnitude higher than that of reference manganites. Surprisingly, the values of the magnetic anisotropy calculated in this way do not coincide with those estimated from measurements of coercive fields which are one order of magnitude smaller. It is proposed that the reason of this anomalous behaviour is a transition of the trivalent Co ions under the external magnetic field from a low-spin to an intermediate-spin state. Such a transition converts the Co3+ ions into Jahn-Teller ions having an only partially quenched orbital angular momentum, which enhances the intra-atomic spin-orbit coupling and magnetic anisotropy.Comment: Accepted of publication in Europhysics Letters, 11 pages, 5 figure

Realization of giant magnetoelectricity in helimagnets

We show that low field magnetoelectric (ME) properties of helimagnets Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22 can be efficiently tailored by Al-substitution level. As x increases, the critical magnetic field for switching electric polarization is systematically reduced from ~1 T down to ~1 mT, and the ME susceptibility is greatly enhanced to reach a giant value of 2.0 x 10^4 ps/m at an optimum x = 0.08. We find that control of nontrivial orbital moment in the octahedral Fe sites through the Al-substitution is crucial for fine tuning of magnetic anisotropy and obtaining the conspicuously improved ME characteristics

МАЛОИЗВЕСТНЫЕ БАКТЕРИИ, ВЫДЕЛЕННЫЕ ПРИ ЗАБОЛЕВАНИЯХ ЧЕЛОВЕКА

The paper is devoted to the study of little-known and previously unknown bacteria isolated from patients with various diseases. Here we present the data on 22 strains that are little-known or previously unknown as human pathogens and isolated from patients with various diseases. Most of the isolates were found to have multiple antibiotic resistances. Moreover, in many conditions potentially pathogenic spore-forming bacteria were identified. Spore formation provides bacteria for survival in the environment and promotes high resistance to antiseptics and disinfectants. Spore-forming bacteria are high survival and especially dangerous as potential hospital-acquired infections because of its antibiotic resistance but the activity of this antibiotic therapy doesn’t concern microbial spores.Работа посвящена изучению малоизвестных и ранее не известных бактерий, изолированных у больных с патологиями различной локализации. Выделенные и изученные 22 штамма малоизвестных бактерий или вообще не описаны ранее как возбудители заболеваний человека, или обнаружены при патологии другой локализации. Большинство полученных бактерий обладает множественной  устойчивостью к различным  антибиотикам. При  разных  заболеваниях в материале обнаружено много потенциально-патогенных спорообразующих   бактерий. Спорообразование   обеспечивает бактериям  сохранение  жизнеспособности в окружающей среде и повышенную устойчивость к антисептикам и дезинфектантам. Спорообразующие бактерии хорошо   сохраняются   и особенно  опасны  в качестве потенциальных  возбудителей внутрибольничных   инфекций,   поскольку резистентны к антибиотикотерапии, активность которой не распространяется на микробные споры