678 research outputs found
Structural investigations on -FeGe at high pressure and low temperature
The structural parameters of -FeGe have been determined at ambient
conditions using single crystal refinement. Powder diffraction have been
carried out to determine structural properties and compressibility for
pressures up to 30 GPa and temperatures as low as 82 K. The discontinuous
change in the pressure dependence of the shortest Fe-Ge interatomic distance
might be interpreted as a symmetry-conserving transition and seems to be
related to a magnetic phase boundary line.Comment: 4 pages, 5 figure
Electronic and Thermoelectric Properties of RuIn_{3-x}A_{x} (A = Sn, Zn)
Recently, we reported [M. Wagner et al., J. Mater. Res. 26, 1886 (2011)]
transport measurements on the semiconducting intermetallic system RuIn3 and its
substitution derivatives RuIn_{3-x}A_{x} (A = Sn, Zn). Higher values of the
thermoelectric figure of merit (zT = 0.45) compared to the parent compound were
achieved by chemical substitution. Here, using density functional theory based
calculations, we report on the microscopic picture behind the measured
phenomenon. We show in detail that the electronic structure of the substitution
variants of the intermetallic system RuIn_{3-x}A_{x} (A = Sn, Zn) changes in a
rigid-band like fashion. This behavior makes possible the fine tuning of the
substitution concentration to take advantage of the sharp peak-like features in
the density of states of the semiconducting parent compound. Trends in the
transport properties calculated using the semi-classical Boltzmann transport
equations within the constant scattering time approximation are in good
agreement with the former experimental results for RuIn_{3-x}Sn_{x}. Based on
the calculated thermopower for the p-doped systems, we reinvestigated the
Zn-substituted derivative and obtained ZnO-free RuIn_{3-x}Zn_{x}. The new
experimental results are consistent with the calculated trend in thermopower
and yield large zT value of 0.8.Comment: PRB Accepted, 11 pages, 10 figure
A lapa do Bugio
A jazida pré-histórica do Bugio constitui uma das mais importantes grutas
sepulcrais da faixa estremenha. Encontrava-se intacta à data das primeiras
escavações, realizadas em 1957 e 1958. Vicissitudes várias que motivaram a
dissolução da primeira equipa e favoreceram diversas depredações, entretanto
realizadas, impediram que, antes do recomeço dos trabalhos, em 1966, mesmo
dos materiais recuperados, se pudessem extrair todas as informações neles
potencialmente contidas. Foi possível, a partir do estudo exaustivo do espólio conservado no Museu
de Sesimbra e no recolhido nas escavações de 1966, estabelecer a seguinte
sucessão cronológica-cultural:
Primeira ocupação - corresponde talvez à ocupação mais importante,
integrável no Neolítico recente-final estremenho. Estreitas analogias com o
"horizonte dolménico" identificado na vizinha Lapa do Fumo e datado pelo
rádio-carbono de 3090 ± 160 a. C. (SERRÃO,1978). A datação realizada no
Bugio deu 2800 ± 45 a.C.
Segunda ocupação- corresponde muito provavelmente a momento inicial
(ou pleno) do Calcolítico, definido pela presença de raros produtos, como o
recipiente de osso recolhido na sep. 7 e "ídolos" de calcário, de osso e marfim.
Terceira ocupação - Calcolítico final, campaniforme - representada pelos
Grupos de Palmela e Inciso. Trata-se da ocupação menos importante,
excessivamente valorizada em trabalhos anteriores, talvez pela grande dispersão
de fragmentos cerâmicos que não ultrapassam, contudo, nove recipientes (alguns
deles representados por apenas um fragmento): taças em calote - (I), de bordo
espessado - (I), de tipo Palmela - (I), caçoilas acampanadas - (2), e vasos
campaniformes - (2), além de dois recipientes de tipologia mal definida.Le gisement préhistorique de Bugio est l 'une des plus importantes grottes
sépulcrales du littoral de l'Estrémadure. Elle a été trouvée intacte lors des
premières fouilles, réalisées en 1957 et 1958. Diverses vicissitudes, qui devaient
aboutir à la dissolution de la première équipe de fouilleurs et favoriser le pillage
du site, empêchèrent la difusion de toute information avant la reprise des travaux
en 1966, même sur le matériel récupéré.
A partir de l' étude exhaustive du mobilier conservé au Musée de Sesimbra
et de celui qui a été découvert en 1966, on a pu établir les niveaux chronologiques
suivants: Première occupation, peut-être la plus importante, s'intégrant dans le
Néolithique récent et final de l'Estrémadure, présentant d' étroites analogies avec
"l'horizon dolménique" identifié sur le site voisin de Lapa do Fumo, daté de
3090 ± 160 a.C. par radio-carbone (SERRÃO, 1978). La datation obtenue à
Bugio est de 2800 ± 45 a.C..
Seconde occupation, correspondant très probablement à la phase initiale ou
médiane du Chalcolithique, définie par de rares productions, comme le récipient
en os recueilli dans la sépulture 7 et les "idoles" en calcaire, en os et en ivoire.
Troisième occupation (Chalcolithique final, Campaniforme) représentée
par les Groupes de Palmela et incisé. Il s'agit d'une occupation moins importante,
surévaluée dans les travaux antérieurs, peut-être en raison de la grande dispersion
des fragments de céramiques qui ne correspondaient, cependant, qu'à neuf
récipients: coupes en calotte (1 ), coupes au bord épais (1), coupes de type de
Palmela (1), casseroles en forme de cloche (2), vases campaniformes (2) et deux
récipients à la typologie mal définie
Guia de coleta de dados de ceratoconjuntivite bovina infecciosa (CBI).
Monitoramento de surtos; Registro dos dados nas tabelas; Registro fotográfico; Coleta de material para análises microbiológicasbitstream/item/176394/1/Documentos-149.pd
Field-induced transition within the superconducting state of CeRh2As2
Funding: We acknowledge funding from the Physics of Quantum Materials department and the research group “Physics of Unconventional Metals and Superconductors (PUMAS)” of the Max Planck Society. C.G. and E.H. acknowledge support from the German Science Foundation (DFG) through grant GE 602/4-1 Fermi-NESt. P.M.R.B. was supported by the Marsden Fund Council from Government funding, managed by Royal Society Te Apārangi. R.K. is supported by the DFG through project. no. KU 3287/1-1. D.F.A. was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under award DE-SC0021971.Materials with multiple superconducting phases are rare. Here, we report the discovery of two-phase unconventional superconductivity in CeRh2As2 Using thermodynamic probes, we establish that the superconducting critical field of its high-field phase is as high as 14 tesla, even though the transition temperature is only 0.26 kelvin. Furthermore, a transition between two different superconducting phases is observed in a c axis magnetic field. Local inversion-symmetry breaking at the cerium sites enables Rashba spin-orbit coupling alternating between the cerium sublayers. The staggered Rashba coupling introduces a layer degree of freedom to which the field-induced transition and high critical field seen in experiment are likely related.PostprintPostprintPeer reviewe
Utilização de imagens termográficas para diagnóstico de ceratoconjuntivite infecciosa bovina em animais da raça Hereford.
Resumo.Fernando Flores Cardoso, Daniel Portella Montardo, José Carlos Ferrugem Moraes, Marcos Flávio Silva Borba, Sandro da Silva Camargo, editores técnicos
Bioengineering commensal bacteria-derived outer membrane vesicles for delivery of biologics to the gastrointestinal and respiratory tract.
Gram-negative bacteria naturally produce and secrete nanosized outer membrane vesicles (OMVs). In the human gastrointestinal tract, OMVs produced by commensal Gram-negative bacteria can mediate interactions amongst host cells (including between epithelial cells and immune cells) and maintain microbial homeostasis. This OMV-mediated pathway for host-microbe interactions could be exploited to deliver biologically active proteins to the body. To test this we engineered the Gram-negative bacterium Bacteroides thetaiotaomicron (Bt), a prominent member of the intestinal microbiota of all animals, to incorporate bacteria-, virus- and human-derived proteins into its OMVs. We then used the engineered Bt OMVs to deliver these proteins to the respiratory and gastrointestinal (GI)-tract to protect against infection, tissue inflammation and injury. Our findings demonstrate the ability to express and package both Salmonella enterica ser. Typhimurium-derived vaccine antigens and influenza A virus (IAV)-derived vaccine antigens within or on the outer membrane of Bt OMVs. These antigens were in a form capable of eliciting antigen-specific immune and antibody responses in both mucosal tissues and systemically. Furthermore, immunisation with OMVs containing the core stalk region of the IAV H5 hemagglutinin from an H5N1 strain induced heterotypic protection in mice to a 10-fold lethal dose of an unrelated subtype (H1N1) of IAV. We also showed that OMVs could express the human therapeutic protein, keratinocyte growth factor-2 (KGF-2), in a stable form that, when delivered orally, reduced disease severity and promoted intestinal epithelial repair and recovery in animals administered colitis-inducing dextran sodium sulfate. Collectively, our data demonstrates the utility and effectiveness of using Bt OMVs as a mucosal biologics and drug delivery platform technology
Chemistry of layered d-metal pnictide oxides and their potential as candidates for new superconductors
Layered d-metal pnictide oxides are a unique class of compounds which
consists of characteristic d-metal pnictide layers and metal oxide layers. More
than 100 of these layered compounds, including the recently discovered Fe-based
superconducting pnictide oxides, can be classified into 9 structure types.
These structure types and the chemical and physical properties of the
characteristic d-metal pnictide layers and metal oxide layers of the layered
d-metal pnictide oxides are reviewed and discussed. Furthermore, possible
approaches to design new superconductors based on these layered d-metal
pnictide oxides are proposed.Comment: 29 pages including 6 tables and 2 figure
Geometric deep learning as a potential tool for antimicrobial peptide prediction
Antimicrobial peptides (AMPs) are components of natural immunity against invading pathogens. They are polymers that fold into a variety of three-dimensional structures, enabling their function, with an underlying sequence that is best represented in a non-flat space. The structural data of AMPs exhibits non-Euclidean characteristics, which means that certain properties, e.g., differential manifolds, common system of coordinates, vector space structure, or translation-equivariance, along with basic operations like convolution, in non-Euclidean space are not distinctly established. Geometric deep learning (GDL) refers to a category of machine learning methods that utilize deep neural models to process and analyze data in non-Euclidean settings, such as graphs and manifolds. This emerging field seeks to expand the use of structured models to these domains. This review provides a detailed summary of the latest developments in designing and predicting AMPs utilizing GDL techniques and also discusses both current research gaps and future directions in the field
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