47 research outputs found

    Theoretical and Experimental Study of (Ba,Sr)TiO 3 Perovskite Solid Solutions and BaTiO 3 /SrTiO 3 Heterostructures

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    This study was supported by the ERA-NET HarvEnPiez project. The authors would like to thank their national funding agencies (Latvian State Education Development Agency, Slovenian Ministry of Higher Education, Science and Technology, Romanian National Authority for Scientific Research and Innovation, CCCDI-UEFISCDI, project number 49/2016 within PNCDI III – M-ERA NET Program).The results of experimental and theoretical ab initio study of structural and piezoelectric properties of (Ba,Sr)TiO3 perovskite solid solutions are discussed and compared. Experimentally, plate-like (Ba,Sr)TiO3 particles were synthesized by the topochemical conversion in the molten salt from Bi4Ti3O12 template plates. All dimensions (side length ≈ 1 µm, thickness ≈ 200–400 nm) were well above the critical size necessary for observation of piezo- and ferroelectricity. The first-principles computations of the structural and electromechanical properties of solid solutions were performed with CRYSTAL14 computer code within the linear combination of atomic orbitals (LCAO) approximation, using three advanced hybrid functionals of the density-functional-theory (DFT). Different chemical compositions are considered for the ferroelectric and paraelectric phases. Calculated structural properties of solid solutions in tetragonal and cubic phases are in a very good agreement with experimental data. Experimentally obtained and calculated band gaps are compared for cubic SrTiO3 and tetragonal BaTiO3. BaTiO3/SrTiO3 heterostructures were considered theoretically for different chemical compositions. The calculated piezoelectric properties of solid solutions and heterostructures in ferroelectric phase are compared. It is predicted that both solid solutions and heterostructures improve the piezoelectric properties of the bulk BaTiO3, but solid solutions are more preferable for equal Sr concentrations.ERA-NET HarvEnPiez project; Latvian State Education Development Agency, Slovenian Ministry of Higher Education, Science and Technology, Romanian National Authority for Scientific Research and Innovation, CCCDI-UEFISCDI, project number 49/2016 within PNCDI III – M-ERA NET Program; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

    PPAR gene and atherosclerosis: Genetic polymorphisms, epigenetics and therapeutic implications

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    Atherosclerosis is the leading cause of mortality and morbidity in the developed world. It is characterized by the formation of a plaque in the walls of middle and large arteries leading to macrovascular complications. Several risk factors are included, with diabetes being one of the most important for the onset and development of atherosclerosis. Due to an increase in the prevalence of diabetes in the world, the incidence of diabetic complications (microvascular and macrovascular) is increasing. Peroxisome proliferator-activated receptor γ (PPARγ) plays a important role in atherosclerotic processes. Peroxisome proliferator activated receptor γ belongs to the superfamily of nuclear receptors, has a great presence in fat tissue, macrophages, and regulates gene expression and most of the processes that lead to the onset and development of atherosclerosis. In this review, we discuss the basic patho-physiological mechanisms of atherosclerosis in type 2 diabetes mellitus (T2DM). Furthermore, we discuss the impact of PPARγ polymorphisms, and the epigenetic mechanisms affecting the onset of atherosclerosis, i.e, DNA methylation and demethylation, histone acetylation and deacetylation, and RNA-based mechanisms. Moreover, we add therapeutic possibilities for acting on epigenetic mechanisms in order to prevent the onset and progression of atherosclerosis

    Steroid biotransforming strains designated Cochliobolus lunatus m118 and Curvularia lunata AT46 are both Curvularia lunata var lunata

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    The two strains designated ''Cochliobolus lunatus m118'' (MUCL 38696) and ''Curvularia lunata AT46'' (MUCL 38697) are both important for production of corticosteroids. The strain Cochliobolus lunatus m118 developed mycelium only; no conidia nor ascomata were observed Curvularia lunata AT46 produced some conidia on current growth media and conditions. We present for the first time the successful conidiation of ''m118'' on the special growth media and light. Although the strains did not cross nor did with other MUCL Curvularia lunata strains, remaining both asexual, they produced identical conidiation on specific media and under near UV light. Both strains gave the same results with API ZYM 20 (Biomerieux) test and they hybridized well with a randomly cloned Cochliobolus lunatus genomic probe. RAPD profiles with different primers showed some identical (species specific) markers and several nonidentical (strain specific) markers. Results demonstate that strains m118 and AT46 which have been widely used in biochemical and molecular biology studies but did not have a documented taxonomical classification, are two non-compatible Curvularia lunata var. lunata strains

    Discovery of novel genetic networks associated with 19 economically important traits in beef cattle

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    Quantitative or complex traits are determined by the combined effects of many loci, and are affected by genetic networks or molecular pathways. In the present study, we genotyped a total of 138 mutations, mainly single nucleotide polymorphisms derived from 71 functional genes on a Wagyu x Limousin reference population. Two hundred forty six F(2) animals were measured for 5 carcass, 6 eating quality and 8 fatty acid composition traits. A total of 2,280 single marker-trait association runs with 120 tagged mutations selected based on the HAPLOVIEW analysis revealed 144 significant associations (P < 0.05), but 50 of them were removed from the analysis due to the small number of animals (< or = 9) in one genotype group or absence of one genotype among three genotypes. The remaining 94 single-trait associations were then placed into three groups of quantitative trait modes (QTMs) with additive, dominant and overdominant effects. All significant markers and their QTMs associated with each of these 19 traits were involved in a linear regression model analysis, which confirmed single-gene associations for 4 traits, but revealed two-gene networks for 8 traits and three-gene networks for 5 traits. Such genetic networks involving both genotypes and QTMs resulted in high correlations between predicted and actual values of performance, thus providing evidence that the classical Mendelian principles of inheritance can be applied in understanding genetic complexity of complex phenotypes. Our present study also indicated that carcass, eating quality and fatty acid composition traits rarely share genetic networks. Therefore, marker-assisted selection for improvement of one category of these traits would not interfere with improvement of another

    Discovery of novel genetic networks associated with 19 economically important traits in beef cattle

    No full text
    <p>Quantitative or complex traits are determined by the combined effects of many loci, and are affected by genetic networks or molecular pathways. In the present study, we genotyped a total of 138 mutations, mainly single nucleotide polymorphisms derived from 71 functional genes on a Wagyu x Limousin reference population. Two hundred forty six F<sub>2</sub> animals were measured for 5 carcass, 6 eating quality and 8 fatty acid composition traits. A total of 2,280 single marker-trait association runs with 120 tagged mutations selected based on the HAPLOVIEW analysis revealed 144 significant associations (P &#60; 0.05), but 50 of them were removed from the analysis due to the small number of animals (&#8804; 9) in one genotype group or absence of one genotype among three genotypes. The remaining 94 single-trait associations were then placed into three groups of quantitative trait modes (QTMs) with additive, dominant and overdominant effects. All significant markers and their QTMs associated with each of these 19 traits were involved in a linear regression model analysis, which confirmed single-gene associations for 4 traits, but revealed two-gene networks for 8 traits and three-gene networks for 5 traits. Such genetic networks involving both genotypes and QTMs resulted in high correlations between predicted and actual values of performance, thus providing evidence that the classical Mendelian principles of inheritance can be applied in understanding genetic complexity of complex phenotypes. Our present study also indicated that carcass, eating quality and fatty acid composition traits rarely share genetic networks. Therefore, marker-assisted selection for improvement of one category of these traits would not interfere with improvement of another.</p
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