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Lithium sodium tetragermanate, LiNaGe4O9, has been prepared by solid-state reaction, by sequentially firing stoichiometric mixtures of Li2CO3, Na2CO3, and GeO2 starting materials in air in the temperature range 773–1073 K. Its unit-cell parameters have been determined by X-ray diffraction: a = 4.68007(3) Å, b = 9.3220(8) Å , c = 15.900(2) Å, and V = 694.113 Å (Z = 4, sp. gr. Pcca). The high-temperature heat capacity of the germanate has been determined using differential scanning calorimetry in the temperature range 320–1050 K. The experimental temperature-dependent heat capacity data, Cp(T), have been used to calculate the principal thermodynamic functions of LiNaGe4O9. [ABSTRACT FROM AUTHOR]

The RGaTi2O7 (R = Sm, Ho, Tm, Yb) substituted titanates have been prepared by solid-state reactions, by firing mixtures of the Ga2O3, TiO2, and R2O3 oxides in air at 1273 and 1573 K, and their crystal structure has been determined using X-ray diffraction. The effect of temperature (320–1000 K) on the heat capacity of the synthesized compounds has been studied by differential scanning calorimetry. The experimental Cp(T) data have been used to calculate the principal thermodynamic functions of the titanates. Using the group contribution method, we evaluated the standard enthalpy and Gibbs energy of formation of the RGaTi2O7 (R = Sm, Ho, Tm, Yb) titanates. [ABSTRACT FROM AUTHOR]

Bi4–xPrxTi3O12 (x = 0.4, 0.8, 1.2, 1.6) solid solutions have been prepared by solid-state reactions, via multistep firing of stoichiometric mixtures of their constituent oxides in air at temperatures from 1003 to 1323 K. Their crystal structure has been determined using X-ray diffraction, and their luminescence spectra have been measured at room temperature. High-temperature heat capacity of polycrystalline substituted bismuth titanate samples has been determined by differential scanning calorimetry. The Cp(T) curves of the solid solutions with x = 0.4 and 0.8 have extrema related to phase transitions. Experimental data have been used to calculate the main thermodynamic functions of the solid solutions. [ABSTRACT FROM AUTHOR]

Titanates Bi2Pr2Ti3O12 and Bi2Nd2Ti3O12 have been obtained by the solid-phase synthesis using sequential annealing of the Bi2O3, Nd2O3, Pr6O11, and TiO2 stoichiometric mixtures in air at temperatures of 1003–1323 K. Their crystal structure has been established by X-ray diffractometry and the high-temperature heat capacity has been determined by differential scanning calorimetry. Based on the experimental Cp = f(T) data, the main thermodynamic functions have been calculated. [ABSTRACT FROM AUTHOR]

The SF-1 (Steroidogenic Factor-1) is a transcription factor known as a key regulator of the steroidogenic gene expression. SF-1 is required for the development and functioning at all levels of the hypothalamic-pituitary-gonadal and adrenal axis. Also it plays an essential role in sex determination. SF-1 is a member of the nuclear receptor superfamily and it activates gene expression by binding to DNA in a monomeric form. Here, we report the results of potential SF-1 binding sites identification by using the SiteGA recognition method. The SiteGA method was implemented using a genetic algorithm (GA) involving a iterative discriminant analyses of local dinucleotide context characteristics. These characteristics were compiled not only over the core binding sites region but over its flanks as well. Developed SiteGA method is characterized by considerably better recognition accuracy when compared to that for the weight matrix method. The experimental tests demonstrated that 83% of the sites recognized by the SiteGA method in the regulatory regions of steroidogenic genes, indeed, interact with the SF-1 factor. We also estimated the density of predicted sites in regulatory region of genes, the members of different functional groups and developed the criterion to search for new SF-1 target genes in genome sequences.

The learning plasticity was shown to be accompanied by a serotonin-induced translocation of Rf 0.58 protein, increasing of the G-protein activity, as well as PKA and c-fos gene expression in Helix. The learning marker Rf 0.58 is absent from the juvenile snails. The AP-1 transcription factors in them cannot be determined or induced with serotonin. The level of CRE factors in juvenile snails was comparable with adult and can be regulated by serotonin. The impossibility of sensitisation and avoidance conditioning reflex in juvenile snails can be explain with the AP-1 factors deficit.

Nucleotide sequences of 188 promoter-containing DNA regions have been studied by the computer statistic analysis. Undecanucleotide NTT(G/C)TTGACA(A/T) or (G/C) X TT(G/C)A(G/C)A(A/T)TT(G/T) (recognition site) and heptanucleotide RTATATR or TATAATR (initiation site) separated by 12-19 base pairs are characteristic of a "generalized" promoter structure. Promoters can function if a minimal level of correspondence for their recognition and initiation sites to a generalized structure is attained (the correspondence function value for the whole structure is not lower than 0,61; for the most effective promoters it may be equal to 1). The transcription start is situated 3-9 base pairs after initiation site, 4-7 pairs distance being the most effective. Transcription can start from any nucleotide, preferably with A or G. The start from A is the most effective if it is contained within the CAC or CAT trinucleotides. The promoter efficiency is enhanced by some additional structural factors: the presence of an extended A-T rich region directly before the recognition site; availability of integral promoter structures or several RNA polymerase binding sites in the preceding nucleotide sequence. A characteristic feature of the promoter is the presence of either the dyadic axial symmetry elements in the initiation and recognition sites as well as in the intermediate region, or the A-T rich area in the latter.