Coherent magnetization precession in ferromagnetic (Ga,Mn)As induced by picosecond acoustic pulses

We show that the magnetization of a thin ferromagnetic (Ga,Mn)As layer can be modulated by picosecond acoustic pulses. In this approach a picosecond strain pulse injected into the structure induces a tilt of the magnetization vector M, followed by the precession of M around its equilibrium orientation. This effect can be understood in terms of changes in magneto-crystalline anisotropy induced by the pulse. A model where only one anisotropy constant is affected by the strain pulse provides a good description of the observed time-dependent response.Comment: 13 pages, 3 figure

Energy exchange between ions of Ce3+ and Tb3+ in crystals of fluoride

Spectroscopic study of fluoride crystals with various concentrations of terbium and cerium is performed. Analysis of these spectra shows that change of nature of rare-earth centers takes place under the variation of concentration of rare-earth ions. It leads to modification of energy transfer at various concentrations of rare-earth ions and, as consequence, to modification of observed spectra

DEVELOPMENT AND VALIDATION OF 3AB-ELISATEST-SYSTEM FOR DETECTION OF ANTIBODIES TO FMD VIRUS NONSTRUCTURAL PROTEINS IN BLOOD SERA FROM CATTLE AND SMALL RUMINANTS

The 3AB-ELISA test-system for detection of antibodies to FMD virus nonstructural proteins in blood sera from cattle and small ruminants was validated. It was discovered that the reaction repeatability and reproducibility exceeded 90%, diagnostic specificity constituted 99,8%, diagnostic sensitivity came up to 96,6%. The high specificity and sensitivity of the 3AB-ELISA test-system was confirmed by international proficiency testings as far as FMD diagnostics and by routine diagnostic and monitoring studies

Efficiency of new local method of treatment and prevention of inflammatory diseases of oral mucous membrane and parodontium in smokers

Treatment and prevention of inflammatory diseases of oral mucous membrane and parodontium at smokers is one of the most difficult problem in stomatology today.Purpose of research: estimation of clinical efficiency of local application of developed agent for oral cavity care apigel at treatment and prevention of inflammatory diseases of oral mucose membrane and parodontium at smokers. Local application of the new apigel based on propolis in the complex medical treatment of smokers patients favourably affects the clinical symptoms of inflammation in the oral mucous membrane and parodontium. As compared with patients who had traditional anti-inflammation therapy with the local use to the stomatologyc gel with chamomile, the patients treated with local application of new apigel had decline of the bleeding gums. The occurred more rapid improvement of inflammation painfulness, which correlated with the improvement of hygienic state of oral cavity and promoted to prevention of bacterial content of damaged mucous surfaces. Estimation of microvasculatory blood stream by the method of ultrasonic Doppler flowmetry revealed more rapid normalization of volume and linear high systole, speed of blood stream in the parodontal tissues in case of use of new local method that testified to the less pronounced inflammation of oral mucosa. The effect of the developed local agent in smokers patients with inflammatory diseases of oral mucose membrane and parodontium at smokers creates the best conditions for removal of violations of oral cavity microbiocenosis and restores structural-functional state of parodontium and oral mucosa.The authors came to conclusion that local application of the offered method of medical treatment reduces terms of renewal of structural-functional integrity of oral mucosa, helps in preventing development of inflammatory complication, improves the hygienic state of oral cavity, renders the regenerative action on oral mucosa tissues, which improves efficiency of medical treatment and quality of life of smokers patients

Ultrafast changes of magnetic anisotropy driven by laser-generated coherent and noncoherent phonons in metallic films

Ultrafast optical excitation of a metal ferromagnetic film results in a modification of the magnetocrystalline anisotropy and induces the magnetization precession. We consider two main contributions to these processes: an effect of noncoherent phonons, which modifies the temperature dependent parameters of the magnetocrystalline anisotropy and coherent phonons in the form of a strain contributing via inverse magnetostriction. Contrary to earlier experiments with high-symmetry ferromagnetic structures, where these mechanisms could not be separated, we study the magnetization response to femtosecond optical pulses in the low-symmetry magnetostrictive galfenol film so that it is possible to separate the coherent and noncoherent phonon contributions. By choosing certain experimental geometry and external magnetic fields, we can distinguish the contribution from a specific mechanism. Theoretical analysis and numerical calculations are used to support the experimental observations and proposed model