3,294 research outputs found

    Observation of Spin-glass-like Behavior in SrRuO3 Epitaxial Thin Films

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    We report the observation of spin-glass-like behavior and strong magnetic anisotropy in extremely smooth (~1-3 \AA) roughness) epitaxial (110) and (010) SrRuO3 thin films. The easy axis of magnetization is always perpendicular to the plane of the film (unidirectional) irrespective of crystallographic orientation. An attempt has been made to understand the nature and origin of spin-glass behavior, which fits well with Heisenberg model.Comment: 5 pages, 5 Figure

    Critical behavior of magnetoresistance near the metal-insulator transition of La₀₇Ca₀₃MnO₃

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    The resistivity, ρ(T), of thin film and bulk samples of La₀₇Ca₀₃MnO₃ is investigated in magnetic fields between 0-10 T and temperatures between 10-340 K. Metallic resistivity, ρlt(T)=ρr+ρ2T2+ρ4.5T4.5, is observed well below the metal–insulator transition (MIT) temperature TMI. For T>TMI, the resistivity is governed by the Shklovskii-Efros variable-range hopping mechanism, giving View the MathML sourceyesBelgorod State Universit

    Usefulness of serum HE4 in endometriotic cysts

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    Usefulness of serum HE4 in endometriotic cyst

    Phylogenetic origins and family classification of typhuloid fungi, with emphasis on Ceratellopsis, Macrotyphula and Typhula (Basidiomycota)

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    Typhuloid fungi are a very poorly known group of tiny clavarioid homobasidiomycetes. The phylogenetic position and family classification of the genera targeted here, Ceratellopsis, Macrotyphula, Pterula sensu lato and Typhula, are controversial and based on unresolved phylogenies. Our six-gene phylogeny with an expanded taxon sampling shows that typhuloid fungi evolved at least twice in the Agaricales (Pleurotineae, Clavariineae) and once in the Hymenochaetales. Macrotyphula, Pterulicium and Typhula are nested within the Pleurotineae. The type of Typhula (1818) and Sclerotium (1790), T. phacorrhiza and S. complanatum (synonym T. phacorrhiza), are encompassed in the Macrotyphula clade that is distantly related to a monophyletic group formed by species usually assigned to Typhula. Thus, the correct name for Macrotyphula (1972) and Typhula is Sclerotium and all Typhula species but those in the T. phacorrhiza group need to be transferred to Pistillaria (1821). To avoid undesirable nomenclatural changes, we suggest to conserve Typhula with T. incarnata as type. Clavariaceae is supported as a separate, early diverging lineage within Agaricales, with Hygrophoraceae as a successive sister taxon to the rest of the Agaricales. Ceratellopsis s. auct. is polyphyletic because C. acuminata nests in Clavariaceae and C. sagittiformis in the Hymenochaetales. Ceratellopsis is found to be an earlier name for Pterulicium, because the type, C. queletii, represents Pterulicium gracile (synonym Pterula gracilis), deeply nested in the Pterulicium clade. To avoid re-combining a large number of names in Ceratellopsis we suggest to conserve it with C. acuminata as type. The new genus Bryopistillaria is created to include C. sagittiformis. The families Sarcomyxaceae and Phyllotopsidaceae, and the suborder Clavariineae, are described as new. Six new combinations are proposed and 15 names typified

    Pindara revisited - evolution and generic limits in Helvellaceae

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    The Helvellaceae encompasses taxa that produce some of the most elaborate apothecial forms, as well as hypogeous ascomata, in the class Pezizomycetes (Ascomycota). While the circumscription of the Helvellaceae is clarified, evolutionary relationships and generic limits within the family are debatable. A robust phylogeny of the Helvellaceae, using an increased number of molecular characters from the LSU rDNA, RPB2 and EF-1 alpha gene regions (4 299 bp) and a wide representative sampling, is presented here. Helvella s.lat. was shown to be polyphyletic, because Helvella aestivalis formed a distant monophyletic group with hypogeous species of Balsamia and Barssia. All other species of Helvella formed a large group with the enigmatic Pindara (/Helvella) terrestris nested within it. The ear-shaped Wynnella constitutes an independent lineage and is recognised with the earlier name Midotis. The clade of the hypogeous Balsamia and Barssia, and H. aestivalis is coherent in the three-gene phylogeny, and considering the lack of phenotypic characters to distinguish Barssia from Balsamia we combine species of Barssia, along with H. aestivalis, in Balsamia. The closed/tuberiform, sparassoid H. astieri is shown to be a synonym of H. lactea; it is merely an incidental folded form of the saddle-shaped H. lactea. Pindara is a sister group to a restricted Helvella, i.e., excluding the /leucomelaena lineage, on a notably long branch. We recognise Pindara as a separate genus and erect a new genus Dissingia for the /leucomelaena lineage, viz. H. confusa, H. crassitunicata, H. leucomelaena and H. oblongispora. Dissingia is supported by asci that arise from simple septa; all other species of Helvellaceae have asci that arise from croziers, with one exception being the /alpina-corium lineage of Helvella s. str. This suggests ascus development from croziers is the ancestral state for the Helvellaceae and that ascus development from simple septa has evolved at least twice in the family. Our phylogeny does not determine the evolutionary relationships within Helvella s. str., but it is most parsimonious to infer that the ancestor of the helvelloids produced subsessile or shortly stipitate, cup-shaped apothecia. This shape has been maintained in some lineages of Helvella s. str. The type species of Underwoodia, Underwoodia columnaris, is a sister lineage to the rest of the Helvellaceae

    Manufacture of Bi-cuprate thin films on MgO single crystal substrates by chemical solution deposition

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    Bi2Sr2CaCu2O8 thin films have been deposited on MgO single crystal substrates by spin-coating a solution based on 2-ethylhexanoate precursors dissolved in xylene. Pyrolysis takes place between 200 degrees C and 450 degrees C and is accompanied by the release of 2-ethylhexanoic acid, CO2 and H2O vapour. Highly c-axis oriented Bi2Sr2CaCu2O8 as well as Er-or Ho-doped Bi2Sr2(Ca, Ln)Cu2O8 (Ln = Er, Ho) films were obtained after heat treatment at 840 degrees C in air

    Pinning Enhancement by Heterovalent Substitution in Y1x_{1-x}REx_{x}Ba2_{2}Cu3_{3}O7δ_{7-\delta}

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    The intragrain pinning in high-TcT_c superconductor compounds Y1x_{1-x}REx_{x}Ba2_{2}Cu3_{3}O7δ_{7-\delta} with low concentration of RE (La, Ce, Pr) was investigated. Magnetic and transport measurements reveal that the pinning is maximal for the concentration of heterovalent RE such that the average distance between the impurity ions in the plane of rare-earth elements close to the diameter of Abrikosov vortices in YBCO.Comment: 11 pages, 6 figures, will be published in SUS

    PIK3R1 fusion drives chemoresistance in ovarian cancer by activating ERK1/2 and inducing rod and ring-like structures

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    Gene fusions are common in high-grade serous ovarian cancer (HGSC). Such genetic lesions may promote tumorigenesis, but the pathogenic mechanisms are currently poorly understood. Here, we investigated the role of a PIK3R1-CCDC178 fusion identified from a patient with advanced HGSC. We show that the fusion induces HGSC cell migration by regulating ERK1/2 and increases resistance to platinum treatment. Platinum resistance was associated with rod and ring-like cellular structure formation. These structures contained, in addition to the fusion protein, CIN85, a key regulator of PI3K-AKT-mTOR signaling. Our data suggest that the fusion-driven structure formation induces a previously unrecognized cell survival and resistance mechanism, which depends on ERK1/2-activation

    Intracrine androgens enhance decidualization and modulate expression of human endometrial receptivity genes

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    The endometrium is a complex, steroid-dependent tissue that undergoes dynamic cyclical remodelling. Transformation of stromal fibroblasts (ESC) into specialised secretory cells (decidualization) is fundamental to the establishment of a receptive endometrial microenvironment which can support and maintain pregnancy. Androgen receptors (AR) are present in ESC; in other tissues local metabolism of ovarian and adrenal-derived androgens regulate AR-dependent gene expression. We hypothesised that altered expression/activity of androgen biosynthetic enzymes would regulate tissue availability of bioactive androgens and the process of decidualization. Primary human ESC were treated in vitro for 1–8 days with progesterone and cAMP (decidualized) in the presence or absence of the AR antagonist flutamide. Time and treatment-dependent changes in genes essential for a) intra-tissue biosynthesis of androgens (5α-reductase/SRD5A1, aldo-keto reductase family 1 member C3/AKR1C3), b) establishment of endometrial decidualization (IGFBP1, prolactin) and c) endometrial receptivity (SPP1, MAOA, EDNRB) were measured. Decidualization of ESC resulted in significant time-dependent changes in expression of AKR1C3 and SRD5A1 and secretion of T/DHT. Addition of flutamide significantly reduced secretion of IGFBP1 and prolactin and altered the expression of endometrial receptivity markers. Intracrine biosynthesis of endometrial androgens during decidualization may play a key role in endometrial receptivity and offer a novel target for fertility treatment
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