Nanocrystalline SiC film thermistors for cryogenic applications.

We developed a heat-sensitive material based on nanocrystalline SiC films obtained by direct deposition of carbon and silicon ions onto sapphire substrates. These SiC films can be used for resistance thermometers operating in the 2 K-300 K temperature range. Having high heat sensitivity, they are relatively low sensitive to the magnetic field.

[Secondary Metabolites of Fungi of the Usti Section, Genus Aspergillus and Their Application in Chemosystematics].

Secondary metabolites of 22 fungal strains (genus Aspergillus, section Usti) isolated at diverse geographic regions, including the Arctic permafrost deposits, were studied. The studied strains were found to synthesize a variety of biologically active compounds, structurally identified as drimane sesqueterpenoids, isoquinoline alkaloids (TMC-120 A−C, derivative 1), meroterpenoids (austalides О and J), and anthraquinone pigments (averufin, versicolorin C). Desferritriacetylfusigen production by A.

[Exometabolites of the Fungal Isolates (Genus Penicillium, Section Chrysogena) from Low-Temperature Ecotopes].

Exometabolites of 22 strains of the genus Penicillium, section Chrysogena isolated from low-temperature ecotopes of various geographical regions were analyzed. The ecotopes included permafrost deposits, frozen volcanic ash, a fossil horse, cryopeg, and water from an Antarctic lake. The studied strains were found to contain exometabolites belonging to the groups of penicillins (penicillin G), chrysogins (chrysogin, 3-acetylquinazolone-4, 2-pyruvoyl aminobenzamide, 2-hydroxypropionyl amunobenzamide, and questiomycin A), roquefortines (3,12-dihydroroquefortine, roquefortine, glandicolines A and B, and meleagrine), xanthocillins (xanthocillin X), and simple tryptophan derivatives (N-acetyltriptamine and indoleacetic acid).

[Biosynthesis of biologically active low-molecular weight compounds by fungi of the genus Penicillium (review)].

The recent data on exometabolite biosynthesis in fungi of the genus Penicillium is summarized. The study of creative species, as well as those isolated from extreme ecotopes, resulted in the identification of a number of novel, biologically active compounds. Alkaloid biosynthesis has been shown to begin on.

[Fungi of the genus Penicillium as producers of physiologically active compounds (review)].

Fungi of the genus Penicillium isolated from little studied habitats are able to synthesize both previously known and new physiologically active compounds with diverse structures. They include secondary metabolites of alkaloid nature, i.e.

[Biosynthesis of fumiquinazolines by the fungus Penicillium thymicola].

Biosynthesis of fumiquinazolines F and G (FQs), PC-2, and pigments by the fungus P. thymicola VKM FW-869 is directly dependent on the content of carbon substrate (mannitol) in the medium. Pigment production prevailed at all of the tested mannitol concentrations.

Role of antibodies to neuronal α7-acetylcholine receptors in myasthenia.

The role of antibodies to a fragment of neuronal acetylcholine receptor was studied by EIA in patients with myasthenia. Antibody levels were significantly higher in patients with generalized myasthenia. Enzyme immunoassay of antibodies by the reaction with acetylcholine receptor fragment can serve as an additional method for studies of autoimmune myasthenia pathogenesis.

[Physiological and biochemical characteristics of fungi of the genus Penicillium as producers of ergot alkaloids and quinocitrinins].

Four cultures of fungi of the genus Penicillium belonging to Furcatum Pitt subgenus, such as P. citrinum Thom, 1910; P. corylophilum Dierckx, 1901; P.

[New producers of biologically active compounds--fungal strains of the genus Penicillium isolated from permafrost].

Screening of producers of secondary metabolites was carried out among 25 fungal strains of Penicillium genus isolated from permafrost in Arctic and Antarctic regions and Kamchatka. Nearly 50% of the investigated strains synthesize biologically active substances of alkaloid nature: ergot alkaloids, diketopiperazines, and quinoline derivatives. A large group of the identified metabolites belongs to mycotoxins.

[Clavine alkaloid biosynthesis by the fungus Penicillium palitans westling 1911 isolated from ancient permafrost deposits].

The relic strain of Penicillium palitans isolated from the ancient permafrost deposits produces clavine alkaloids such as festuclavine, fumigaclavine A, and fumigaclavine B. Alkaloid biosynthesis is concurrent with the growth. Tryptophan and zinc ion additives to the culture medium stimulate the synthesis of alkaloids.

[Effect of various factors on the biosynthesis of piscarinines, secondary metabolites of the fungus Penicillium piscarium westling].

Piscarinines A and B were synthesized most actively during the surface cultivation of the fungus Penicillium piscarium in a complex medium (5.5 mg/l). Under conditions of submerged cultivation in a mineral medium, the yield of piscarinines was two times lower.

[Growth and biosynthesis of rugulovasines in Penicillium variabile Sopp 1912].

Production of clavine alkaloids rugulovasines by P. variabile did not depend on the habitat of the producers. During submerged cultivation on a simple synthetic medium in early growth stages, microcyclic conidiation was observed in the tested fungi; its presence or absence, as well as the activity of the cultures as to biosynthesis of rugulovasines, depended on the composition of the culture medium.

[Fixation of metacentric chromosomes in populations of the common shrew Sorex araneus L. from populations of Eastern Europe].

In this review, we discuss the processes of fixation of Robertsonian chromosome fusions in populations of the common shrew Sorex araneus L. Various Robertsonian fusions, accumulating in populations, create an illusion of large chromosomal rearrangements, reciprocal translocations of complete chromosome arms. The use of these rearrangements for phylogenetic reconstructions results in false conclusions.

[Effect of quinocitrinines from the fungus Penicillium citrinum on the respiration of yeasts and bacteria].

We studied the effect of quinocitrinines on the respiratory activity of yeasts (Yarrowia lipolytica) and bacteria (Arthrobacter globiformis). Quinocitrinines were shown to activate respiration of native cells in both types of organisms. Studies of yeast mitochondria showed that quinocitrinine exerts an uncoupling effect on oxidative phosphorylation, which activates the respiration, reduces the respiratory control, and decreases the ADP/O ratio.

[GABA metabolism and neuroactive amino acids in the rat brain in morphine withdrawal syndrome].

The changes in the neuroactive amino acid contents, GABA metabolism and TCA reactions have been studied in rat brain regions under experimental morphine withdrawal (MW). MW was developed by means of the cessation of morphine intraperitoneal injections 1 and 36 hours, 3 and 7 days after the course of morphine administration for 7 days. In cortex the significant increase in the contents of glutamate, glutamine, asparagine, and alanine was observed in remote terms of MW.

[Transport of ergot alkaloids and quinocitrinins in the producing fungus Penicillium citrinum].

The decrease in the concentration of alkaloids in the culture liquid of Penicillium citrinum grown to the early stationary phase was found to be due to the uptake of quinocitrinins and ergot alkaloids by fungal cells. The ability of the fungal mycelium to absorb autogenous quinocitrinins does not depend on the mycelium age, whereas its ability to absorb ergot alkaloids is higher in the young than in the 12-day-old mycelium. The uptake of exogenously added ergot alkaloids by the fungal mycelium is accompanied by excretion of intracellular quinocitrinins.

[The fungus Penicillium variabile sopp 1912 isolated from permafrost deposits as a producer of rugulovasines].

It has been established that relict fungi Penicillium variabile Sopp can synthesize clavine alkaloids, rugulovasines A and B, which are revealed in this species for the first time. Submerged cultivation of the strain-producer revealed several microcycles of conidia formation. The synthesis of alkaloids was also of a cyclic character.

[The effect of some amino acids on the growth and biosynthesis of ergot alkaloids and quinocitrinins in the fungus Penicillium citrinum Thom 1910].

The effect of some amino acids, added to the medium either during inoculation or in the stationary growth phase, on the growth and biosynthesis of ergot alkaloids and quinocitrinins in the fungus Penicillium citrinum VKM FW-800 has been studied. Exogenously added amino acids were mostly utilized in primary metabolism. When added during inoculation, tryptophan and leucine virtually did not influence fungal growth and synthesis of the alkaloids, whereas the addition of isoleucine enhanced the biomass accumulation.

[Fungus Penicillium citrinum, isolated from permafrost sediments, as a producer of ergot alkaloids and new quinoline alkaloids quinocitrinines].

Quinocitrinines and ergot alkaloids are synthesized by the strain Penicillium citrinum VKM FW-800 as the culture grows. The major part of these secondary metabolites are secreted into the medium. In the phase of growth deceleration, these metabolites were partly absorbed by the producer cells.

[Chronic morphine intoxication and metabolism of neuroactive amino acids in the rat brain].

The influence of chronic morphine intoxication (for 7, 14 and 21-days) has been studied on the contents of neuroactive amino acids (GABA, glutamate, glutamine, alanine, aspartate, glycine, taurine) and on the activities of their metabolizing enzymes (GABA-transaminase, succinic semialdehyde dehydrogenase, succinic dehydrogenase, alanine- and aspartate-aminotransferase) in the rat brain regions: cortex, brain stem and cerebellum. We detected the significant decrease of glutamate level and the enhancement of GABA and aspartate levels in cortex after long-term morphine administration. In brain stem the increase in the contents of GABA, glutamine and taurine was noted together with the tendency in attenuation of this effect when intoxication was prolonged.

[GABA metabolism and contents of neuroactive amino acids in rat brain after acute morphine administration].

The activities of GABA-catabolizing enzymes (GABA-transaminase and succinic semialdehyde dehydrogenase), succinate dehydrogenase, alanine and aspartate amino transferases, the contents of GABA, glutamate, glutamine, alanine, aspartate and glycine were studied in rat brain regions after acute morphine administration. Intraperitoneal (i.p.

[Penicillium expansum, a resident fungal strain of the orbital complex Mir, producing xanthocillin X and questiomycin A].

It was demonstrated that the fungus Penicillium expansum 2-7, a resident strain of the orbital complex Mir, which became dominating at the end of a long-term space flight, formed biologically active secondary metabolites (antibiotics). Using physicochemical methods, these metabolites were identified as xanthocyllin X and questiomycin A. Time courses of their biosyntheses during growth and development of the producer culture were studied.