Magnetic phase diagram of the olivine-type Mn2GeO4 single crystal estimated from magnetic, resonance and thermodynamic properties.

Mn2GeO4 single crystals with the olivine structure grown by the modified flux method have been investigated. Pronounced magnetic phase transitions at T1 = 47.7 K, T2 = 17 K and T3 = 5.5 K, with T2 being dependent on an applied magnetic field, have been found. Based on the data of magnetic, resonance and temperature measurements, the entire phase diagram of Mn2GeO4 has been built. Mn2GeO4 is shown to be a material with a complex magnetic structure consisting of two magnetic subsystems.

[Phase II clinical trial of autologous dendritic cell vaccine with immunologic adjuvant in cutaneous melanoma patients].

This paper describes the clinical results and immunologic changes in cutaneous melanoma patients receiving active specific immunotherapy with autologous dendritic cell vaccine (DCV) in combination with cyclophosphamide used as immunologic adjuvant. Twenty eight patients with morphologically verified stage III-IV cutaneous melanoma receiving therapy in N. N. Petrov Research Institute of Oncology between 2008 and 2011 were included in the study. All patients signed an informed consent form. Nineteen patients (67,9%) received DCV in therapeutic setting, 9 (32,1%) received it in adjuvant setting. DCV therapy was well tolerated. No serious adverse events were registered. Frequent adverse events included Grade 1-2 unspecific symptoms (fever, fatigue, flu-like symptoms) observed in 22% patients after 3,5% of vaccinations. In therapeutic settings the use DCV lead to clinical effect (PR+SD) in 36,6% of patients. PR was observed in 5% of (95% CI 0-15%) patients, SD in 31,6% (95% CI 13-56%). Duration of the objective responses was 168-965+days. Addition of immunologic adjuvant (cyclophosphamide 300 mg/m2 IV 2 hours) 3 days before vaccination increased its efficacy. In this patients group (n=12) the therapy lead to clinical benefit in 42% (95% CI 17-69%) of cases, median time to progression was 91 (95% CI 55-126) days. This regimen was selected for adjuvant therapy. In the adjuvant therapy group (n=9) the median time to progression was 112 (95% CI 58-166) days. Immunologic monitoring showed correlation ofT- and B-cell immune response with DCV clinical efficacy (p<0,05), no correlation with delayed hypersensivity reaction was observed (p>0,1). DCV is well tolerated and shows immunological and clinical response in stage III-IV skin melanoma patients.

Dielectric properties of a mixed-valence Pb3Mn7O15 manganese oxide.

We investigated the low-frequency dielectric properties of a Pb(3)Mn(7)O(15) single crystal with manganese ions in the mixed-valence state (Mn(3+)/Mn(4+)). Dielectric relaxation was found in the frequency window from 20 to 100 kHz in the temperature range 110-180 K. The dielectric spectra of the crystal were analyzed using a Debye model. Estimations made within the model and analysis of resistivity data suggest that the relaxation behavior of the dielectric constant is related to polaronic charge carrier hopping. Around 250 K, charge ordering occurs in the crystal when the Mn(3+) and Mn(4+) ions are arranged in a specific order among the crystal sites. With a decrease in temperature, an ac electric field can induce a charge hop between the equivalent lattice sites available, related to crystal symmetry. This hopping is equivalent to the reorientation of an electric dipole that yields Debye-type behavior of the complex dielectric constant. The observed anisotropy in the behavior of the dielectric properties and resistivity can be attributed to a pronounced two-dimensional character of the crystal structure.

Magnetic properties of MnGeO(3) single crystals with orthorhombic structure.

The current report is devoted to the further study of magnetic properties of MnGeO(3) single crystals with orthorhombic symmetry Pbca. New data from magnetic measurements in magnetic fields up to 80 kOe are presented. A spin flop transition is observed at H(sf) = 35 kOe and T = 4.2 K along the a-axis. The exchange and anisotropy fields are determined. The magnetic structure of MnGeO(3) with T(N)≈36 K is qualitatively described using a two-sublattice model.

[The diagnosis of mycotoxin hepatitis in swine]. / Diagnostika mikotoksicheskogo gepatita svinei.

Mycotoxin hepatitis which develops in pigs when they eat fodder contaminated by mycotoxin (sterigmatocystin) is registered at large pig breeding farms of Ukraine. Diagnostics of mycotoxin hepatitis of pigs induced by sterigmatocystin is based on clinical-epizootiological studies and mycotoxin analysis of the fodder including detection of fungi, producers of sterigmatocystin and determination of the content of mycotoxin itself. The authors have suggested a method based on extraction of mycotoxin from the fodder by means of the mixture of chloroform and 4% water solution of potassium chloride, on concentration of the chloroform residue, its separation in a thin layer of silicagel, and UV examination of chromatograms. The method sensitivity is 30 micrograms per 1 kg of the product. This method will permit diagnosis of mycotoxin hepatitis in animals and will promote timely prophylactic measures. The method is easy to be applied in veterinary laboratories.

[A method for determining the toxigenicity of micromycetes]. / Metod opredeleniia toksigennosti mikromitsetov.

A method is suggested to determine toxigenicity of microscopic fungi from genera Aspergillus, Penicillium, Fusarium, etc. which contaminate fodder, food products and environment objects. The method is based on the property of micromycetes isolated from fodder, food products and environment objects to produce mycotoxins under optimal conditions of their cultivation on the nutrient media. Their further extraction by the organic solvent, evaporation and emulsification of the extract and its peroral introduction to young female rats cause a disease and death of animals. The suggested method may be used for recognizing and preventing mycotoxicoses of farm animals and poultry.