Anomalous thermoelectric transport phenomena from interband electron-phonon scattering

The Seebeck coefficient and electrical conductivity are two critical quantities to optimize simultaneously in designing thermoelectric materials, and they are determined by the dynamics of carrier scattering. We uncover a new regime where the co-existence at the Fermi level of multiple bands with different effective masses leads to strongly energy-dependent carrier lifetimes due to intrinsic electron-phonon scattering. In this anomalous regime, electrical conductivity decreases with carrier concentration, Seebeck coefficient reverses sign even at high doping, and power factor exhibits an unusual second peak. We discuss the origin and magnitude of this effect using first-principles Boltzmann transport calculations and simplified models. We also identify general design rules for using this paradigm to engineer enhanced performance in thermoelectric materials.Comment: 11 pages, 7 figure

POLITICAL INSTITUTE OF THE STATE IN THE CONTEXT OF THE HISTORICAL AND TYPOLOGICAL ANALYSIS

Abstract. Article is devoted to problems of structuring state created history taking into account variety social, political, forms, various speed of a political genesis. Problems of allocation of development stages of the political organizations (statehood) taking into account uncertainty of the general units of the analysis, terms and concepts of rather various paradigms of structuring and a periodization of history are considered. It is shown that the decisive force causing transformation of all other public sectors is growth, distribution and deduction of a dominant position of the most effective in the conditions of this period of a political regime.Key words: historical, typological analysis, potestarny structures, historicism, Kondratiyev’s paradigm,political regime

First-principles Landau-like potential for BiFeO3_3 and related materials

In this work we introduce the simplest, lowest-order Landau-like potential for BiFeO$_3$ and La-doped BiFeO$_3$ as an expansion around the paraelectric cubic phase in powers of polarization, FeO$_6$ octahedral rotations and strains. We present an analytical approach for computing the model parameters from density functional theory. We illustrate our approach by computing the potentials for BiFeO$_3$ and La$_{0.25}$Bi$_{0.75}$FeO$_3$ and show that, overall, we are able to capture the first-principles results accurately. The computed models allow us to identify and explain the main interactions controlling the relative stability of the competing low-energy phases of these compounds.Comment: 12 pages, 6 figure

Instituto político del Estado en el contexto del análisis histórico y tipológico

The article is devoted to problems of structuring state created history taking into account a variety of social, political, forms, various speeds of political genesis. Problems of allocation of development stages of the political organizations (statehood) taking into account uncertainty of the general units of the analysis, terms, and concepts of rather various paradigms of structuring and periodization of history are considered. It is shown that the decisive force causing the transformation of all other public sectors is growth, distribution, and deduction of a dominant position of the most effective in the conditions of this period of a political regime.El artículo está dedicado a los problemas de estructuración de la historia creada por el estado teniendo en cuenta una variedad de formas sociales, políticas, diversas velocidades de génesis política. Se consideran los problemas de asignación de etapas de desarrollo de las organizaciones políticas (estatismo) teniendo en cuenta la incertidumbre de las unidades generales del análisis, los términos y los conceptos de varios paradigmas de estructuración y periodización de la historia. Se muestra que la fuerza decisiva que causa la transformación de todos los demás sectores públicos es el crecimiento, la distribución y la deducción de una posición dominante de los más efectivos en las condiciones de este período de un régimen político

Difficulties in diagnosis of adenomas with mixed prolactin and growth hormone secretion: case presentation

Hyperpolactinemia is a persistent excess of prolactin in the blood serum. The symptom complex of hyperprolactinemia primarily consists of disturbances in function of the reproductive system. The secretion of prolactin is under complex neuroendocrine control, which involves factors of different nature: neurotransmitters, hormones of the peripheral endocrine glands. In most cases, prolactin is secreted by pituitary cells - lactotrophs, but in some cases, hypersecretion of prolactin is combined with an excess production of growth hormone, which is typical for tumors originating from the line of progenitor cells of lactotrophs and somatotrophs of the pituitary gland, mammosomatotrophs. In this case, the symptom complex of hyperprolactinemia is accompanied by clinical manifestations of acromegaly. In patients with acromegaly, the cause of hyperprolactinemia may be pituitary stalk compression or mixed secretion of prolactin and growth hormone. Differentiation of lactotropic and somatotropic pituitary cells is determined by transcription factor Pit-1. These cell lineages are closely connected,  and this may be one of the reasons for formation of tumors with mixed secretion. Reports of late presentation of acromegaly in patients previously diagnosed with prolactinomas have also been described in literature.Clinical manifestations of hyperprolactinemia can cause the patient to seek doctor’s attention before acromegalic changes in appearance develop. Careful attention is needed both to the primary diagnosis and to the clinical course of the disease in patients with hyperprolactinemia and pituitary adenoma: full assessment of hormonal status with mandatory evaluation of IGF-1 is crucial at initial examination, during further observation it may be advised to consider periodic evaluation of IGF-1 in addition to assessment of prolactin and the size of adenoma.  Pituitary adenomas with mixed secretion may have a poorer prognosis

Genomic analyses inform on migration events during the peopling of Eurasia.

High-coverage whole-genome sequence studies have so far focused on a limited number of geographically restricted populations, or been targeted at specific diseases, such as cancer. Nevertheless, the availability of high-resolution genomic data has led to the development of new methodologies for inferring population history and refuelled the debate on the mutation rate in humans. Here we present the Estonian Biocentre Human Genome Diversity Panel (EGDP), a dataset of 483 high-coverage human genomes from 148 populations worldwide, including 379 new genomes from 125 populations, which we group into diversity and selection sets. We analyse this dataset to refine estimates of continent-wide patterns of heterozygosity, long- and short-distance gene flow, archaic admixture, and changes in effective population size through time as well as for signals of positive or balancing selection. We find a genetic signature in present-day Papuans that suggests that at least 2% of their genome originates from an early and largely extinct expansion of anatomically modern humans (AMHs) out of Africa. Together with evidence from the western Asian fossil record, and admixture between AMHs and Neanderthals predating the main Eurasian expansion, our results contribute to the mounting evidence for the presence of AMHs out of Africa earlier than 75,000 years ago.Support was provided by: Estonian Research Infrastructure Roadmap grant no 3.2.0304.11-0312; Australian Research Council Discovery grants (DP110102635 and DP140101405) (D.M.L., M.W. and E.W.); Danish National Research Foundation; the Lundbeck Foundation and KU2016 (E.W.); ERC Starting Investigator grant (FP7 - 261213) (T.K.); Estonian Research Council grant PUT766 (G.C. and M.K.); EU European Regional Development Fund through the Centre of Excellence in Genomics to Estonian Biocentre (R.V.; M.Me. and A.Me.), and Centre of Excellence for Genomics and Translational Medicine Project No. 2014-2020.4.01.15-0012 to EGC of UT (A.Me.) and EBC (M.Me.); Estonian Institutional Research grant IUT24-1 (L.S., M.J., A.K., B.Y., K.T., C.B.M., Le.S., H.Sa., S.L., D.M.B., E.M., R.V., G.H., M.K., G.C., T.K. and M.Me.) and IUT20-60 (A.Me.); French Ministry of Foreign and European Affairs and French ANR grant number ANR-14-CE31-0013-01 (F.-X.R.); Gates Cambridge Trust Funding (E.J.); ICG SB RAS (No. VI.58.1.1) (D.V.L.); Leverhulme Programme grant no. RP2011-R-045 (A.B.M., P.G. and M.G.T.); Ministry of Education and Science of Russia; Project 6.656.2014/K (S.A.F.); NEFREX grant funded by the European Union (People Marie Curie Actions; International Research Staff Exchange Scheme; call FP7-PEOPLE-2012-IRSES-number 318979) (M.Me., G.H. and M.K.); NIH grants 5DP1ES022577 05, 1R01DK104339-01, and 1R01GM113657-01 (S.Tis.); Russian Foundation for Basic Research (grant N 14-06-00180a) (M.G.); Russian Foundation for Basic Research; grant 16-04-00890 (O.B. and E.B); Russian Science Foundation grant 14-14-00827 (O.B.); The Russian Foundation for Basic Research (14-04-00725-a), The Russian Humanitarian Scientific Foundation (13-11-02014) and the Program of the Basic Research of the RAS Presidium “Biological diversity” (E.K.K.); Wellcome Trust and Royal Society grant WT104125AIA & the Bristol Advanced Computing Research Centre (http://www.bris.ac.uk/acrc/) (D.J.L.); Wellcome Trust grant 098051 (Q.A.; C.T.-S. and Y.X.); Wellcome Trust Senior Research Fellowship grant 100719/Z/12/Z (M.G.T.); Young Explorers Grant from the National Geographic Society (8900-11) (C.A.E.); ERC Consolidator Grant 647787 ‘LocalAdaptatio’ (A.Ma.); Program of the RAS Presidium “Basic research for the development of the Russian Arctic” (B.M.); Russian Foundation for Basic Research grant 16-06-00303 (E.B.); a Rutherford Fellowship (RDF-10-MAU-001) from the Royal Society of New Zealand (M.P.C.)

Ferroelectric/paraelectric superlattices for energy storage

The polarization response of antiferroelectrics to electric fields is such that the materials can store large energy densities, which makes them promising candidates for energy storage applications in pulsed-power technologies. However, relatively few materials of this kind are known. Here we consider ferroelectric/paraelectric superlattices as artificial electrostatically-engineered antiferroelectrics. Specifically, using high-throughput second-principles calculations, we engineer PbTiO$_{3}$/SrTiO$_{3}$ superlattices to optimize their energy-storage performance at room temperature (to maximize density and release efficiency) with respect to different design variables (layer thicknesses, epitaxial conditions, stiffness of the dielectric layer). We obtain results competitive with the state-of-the-art antiferroelectric capacitors and reveal the mechanisms responsible for the optimal properties.Comment: 8 pages, 5 figure

First-principles predictions of HfO2-based ferroelectric superlattices

Abstract The metastable nature of the ferroelectric phase of HfO2 is a significant impediment to its industrial application as a functional ferroelectric material. In fact, no polar phases exist in the bulk phase diagram of HfO2, which shows a dominant non-polar monoclinic ground state. As a consequence, ferroelectric orthorhombic HfO2 is stabilized either kinetically or via epitaxial strain. Here, we propose an alternative approach, demonstrating the feasibility of thermodynamically stabilizing polar HfO2 in superlattices with other simple oxides. Using the composition and stacking direction of the superlattice as design parameters, we obtain heterostructures that can be fully polar, fully antipolar or mixed, with improved thermodynamic stability compared to the orthorhombic polar HfO2 in bulk form. Our results suggest that combining HfO2 with an oxide that does not have a monoclinic ground state generally drives the superlattice away from this non-polar phase, favoring the stability of the ferroelectric structures that minimize the elastic and electrostatic penalties. As such, these diverse and tunable superlattices hold promise for various applications in thin-film ferroelectric device