980 resultados para Žerotína, Karel z, 1564-1636.


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The title compound, C15H16N4S, exists in the Z conformation with the thionyl S atom lying cis to the azomethine N atom. The shortening of the N—N distance [1.3697 (17) A ° ] is due to extensive delocalization with the pyridine ring. The hydrazine– carbothioamide unit is almost planar, with a maximum deviation of 0.013 (2) A ° for the amide N atom. The stability of this conformation is favoured by the formation of an intramolecular N—H N hydrogen bond. The packing of the molecules involves no classical intermolecular hydrogenbonding interactions; however, a C—H interaction occurs

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With a relativistic Hartree-Fock-Slater calculation we determined the most stable configurations of the elements of the possibly quasistable island around Z = 164. It is found that the expected noble gas at Z = 168 should not occur, but instead the element Z = 164 should have the properties of a noble gas.

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Listed here for the elements Z = 100, fermium, to Z = 173 are energy eigenvalues and total energies found from relativistic Dirac-Fock-Slater calculations. The effect of high ionization on the energy eigenvalues is presented for two exarnples. The use of these tables in connection with the energy levels of superheavy elements and molecular orbital (MO) x-ray transitions in superheavy quasiatoms, is discussed. In addition, abrief comparison between the results of the Dirac-Fock-Slater and Dirac-Fock calculations is given.

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The chemical elements up to Z = 172 are calculated with a relativistic Hartree-Fock-Slater program taking into account the effect of the extended nucleus. Predictions of the binding energies, the X-ray spectra and the number of electrons inside the nuclei are given for the inner electron shells. The predicted chemical behaviour will be discussed for a11 elements between Z = 104-120 and compared with previous known extrapolations. For the elements Z = 121-172 predictions of their chemistry and a proposal for the continuation of the Periodic Table are given. The eighth chemical period ends with Z = 164 located below Mercury. The ninth period starts with an alkaline and alkaline earth metal and ends immediately similarly to the second and third period with a noble gas at Z = 172. Mit einem relativistischen Hartree-Fock-Slater Rechenprogramm werden die chemischen Elemente bis zur Ordnungszahl 172 berechnet, wobei der Einfluß des ausgedehnten Kernes berücksichtigt wurde. Für die innersten Elektronenschalen werden Voraussagen über deren Bindungsenergie, das Röntgenspektrum und die Zahl der Elektronen im Kern gemacht. Die voraussichtliche Chemie der Elemente zwischen Z = 104 und 120 wird diskutiert und mit bereits vorhandenen Extrapolationen verglichen. Für die Elemente Z = 121-172 wird eine Voraussage über das chemische Verhalten gegeben, sowie ein Vorschlag für die Fortsetzung des Periodensystems gemacht. Die achte chemische Periode endet mit dem Element 164 im Periodensystem unter Quecksilber gelegen. Die neunte Periode beginnt mit einem Alkali- und Erdalkalimetall und endet sofort wieder wie in der zweiten und dritten Periode mit einem Edelgas bei Z = 172.

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Ab initio fully relativistic SCF molecular calculations of energy eigenvalues as well as coupling-matrix elements are used to calculate the 1s_\sigma excitation differential cross section for Ne-Ne and Ne-O in ion-atom collisions. A relativistic perturbation treatment which allows a direct comparison with analogous non-relativistic calculations is also performed.

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The electron screening correction in the X-ray transitions in muonic atoms is calculated within a relativistic SCF Hartree-Fock procedure for many transitions and all Z.

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The ground state (J = 0) electronic correlation energy of the 4-electron Be-sequence is calculated in the Multi-Configuration Dirac-Fock approximation for Z = 4-20. The 4 electrons were distributed over the configurations arising from the 1s, 2s, 2p, 3s, 3p and 3d orbitals. Theoretical values obtained here are in good agreement with experimental correlation energies.

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Incluye índice de entradas (p. 9-27)

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Factor analysis as frequent technique for multivariate data inspection is widely used also for compositional data analysis. The usual way is to use a centered logratio (clr) transformation to obtain the random vector y of dimension D. The factor model is then y = Λf + e (1) with the factors f of dimension k < D, the error term e, and the loadings matrix Λ. Using the usual model assumptions (see, e.g., Basilevsky, 1994), the factor analysis model (1) can be written as Cov(y) = ΛΛT + ψ (2) where ψ = Cov(e) has a diagonal form. The diagonal elements of ψ as well as the loadings matrix Λ are estimated from an estimation of Cov(y). Given observed clr transformed data Y as realizations of the random vector y. Outliers or deviations from the idealized model assumptions of factor analysis can severely effect the parameter estimation. As a way out, robust estimation of the covariance matrix of Y will lead to robust estimates of Λ and ψ in (2), see Pison et al. (2003). Well known robust covariance estimators with good statistical properties, like the MCD or the S-estimators (see, e.g. Maronna et al., 2006), rely on a full-rank data matrix Y which is not the case for clr transformed data (see, e.g., Aitchison, 1986). The isometric logratio (ilr) transformation (Egozcue et al., 2003) solves this singularity problem. The data matrix Y is transformed to a matrix Z by using an orthonormal basis of lower dimension. Using the ilr transformed data, a robust covariance matrix C(Z) can be estimated. The result can be back-transformed to the clr space by C(Y ) = V C(Z)V T where the matrix V with orthonormal columns comes from the relation between the clr and the ilr transformation. Now the parameters in the model (2) can be estimated (Basilevsky, 1994) and the results have a direct interpretation since the links to the original variables are still preserved. The above procedure will be applied to data from geochemistry. Our special interest is on comparing the results with those of Reimann et al. (2002) for the Kola project data

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Resumen tomado de la publicación

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Descripci??n del centro Z??kladn?? Skola, de la Rep??blica Checa, tras la visita realizada por profesorado del Colegio P??blico Los Campos de Corvera de Asturias, en el marco de la Acci??n Commenius en la que ambos centros participan conjuntamente. Los alumnos checos participan en el proyecto mediante la elaboraci??n de cuentos.

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El marcaje de proteínas con ubiquitina, conocido como ubiquitinación, cumple diferentes funciones que incluyen la regulación de varios procesos celulares, tales como: la degradación de proteínas por medio del proteosoma, la reparación del ADN, la señalización mediada por receptores de membrana, y la endocitosis, entre otras (1). Las moléculas de ubiquitina pueden ser removidas de sus sustratos gracias a la acción de un gran grupo de proteasas, llamadas enzimas deubiquitinizantes (DUBs) (2). Las DUBs son esenciales para la manutención de la homeostasis de la ubiquitina y para la regulación del estado de ubiquitinación de diferentes sustratos. El gran número y la diversidad de DUBs descritas refleja tanto su especificidad como su utilización para regular un amplio espectro de sustratos y vías celulares. Aunque muchas DUBs han sido estudiadas a profundidad, actualmente se desconocen los sustratos y las funciones biológicas de la mayoría de ellas. En este trabajo se investigaron las funciones de las DUBs: USP19, USP4 y UCH-L1. Utilizando varias técnicas de biología molecular y celular se encontró que: i) USP19 es regulada por las ubiquitin ligasas SIAH1 y SIAH2 ii) USP19 es importante para regular HIF-1α, un factor de transcripción clave en la respuesta celular a hipoxia, iii) USP4 interactúa con el proteosoma, iv) La quimera mCherry-UCH-L1 reproduce parcialmente los fenotipos que nuestro grupo ha descrito previamente al usar otros constructos de la misma enzima, y v) UCH-L1 promueve la internalización de la bacteria Yersinia pseudotuberculosis.

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New hetaryl- and alkylidenerhodanine derivatives 3a-d, 3e, and 4a-d were prepared from heterocyclic aldehydes 1a-d or acetaldehyde 1e. The treatment of several rhodanine derivatives 3a-d and 3e with piperidine or morpholine in THF under reflux, afforded (Z)-5-(hetarylmethylidene)-2-(piperidin-1-yl) thiazol-4(5H)-ones and 2-morpholinothiazol-4(5H)-ones 5a-d, 6a-d, and (Z)-5-ethylidene-2-morpholinothiazol-4(5H)-one (5e), respectively, in good yields. Structures of all compounds were determined by IR, 1D and 2D NMR and mass spectrometry. Several of these compounds were screened by the U.S. National Cancer Institute (NCI) to assess their antitumor activity against 60 different human tumor cell lines. Compound 3c showed high activity against HOP-92 (Non-Small Cell Lung Cancer), which was the most sensitive cell line, with GI(50) = 0.62 mu M and LC50 > 100 mu M from the in vitro assays. In vitro antifungal activity of these compounds was also determined against 10 fungal strains. Compound 3e showed activity against all fungal strains tested, but showed high activity against Saccharomyces cerevisiae (MIC 3.9 mu g/mL).