975 resultados para Coenzyme Q(10)


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El pie de imp. tomado del colofón

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A unified solution framework is presented for one-, two- or three-dimensional complex non-symmetric eigenvalue problems, respectively governing linear modal instability of incompressible fluid flows in rectangular domains having two, one or no homogeneous spatial directions. The solution algorithm is based on subspace iteration in which the spatial discretization matrix is formed, stored and inverted serially. Results delivered by spectral collocation based on the Chebyshev-Gauss-Lobatto (CGL) points and a suite of high-order finite-difference methods comprising the previously employed for this type of work Dispersion-Relation-Preserving (DRP) and Padé finite-difference schemes, as well as the Summationby- parts (SBP) and the new high-order finite-difference scheme of order q (FD-q) have been compared from the point of view of accuracy and efficiency in standard validation cases of temporal local and BiGlobal linear instability. The FD-q method has been found to significantly outperform all other finite difference schemes in solving classic linear local, BiGlobal, and TriGlobal eigenvalue problems, as regards both memory and CPU time requirements. Results shown in the present study disprove the paradigm that spectral methods are superior to finite difference methods in terms of computational cost, at equal accuracy, FD-q spatial discretization delivering a speedup of ð (10 4). Consequently, accurate solutions of the three-dimensional (TriGlobal) eigenvalue problems may be solved on typical desktop computers with modest computational effort.

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The increasing demands in MEMS fabrication are leading to new requirements in production technology. Especially the packaging and assembly require high accuracy in positioning and high reproducibility in combination with low production costs. Conventional assembly technology and mechanical adjustment methods are time consuming and expensive. Each component of the system has to be positioned and fixed. Also adjustment of the parts after joining requires additional mechanical devices that need to be accessible after joining.

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After a criticism on today’s model for electrical noise in resistors, we pass to use a Quantum-compliant model based on the discreteness of electrical charge in a complex Admittance. From this new model we show that carrier drift viewed as charged particle motion in response to an electric field is unlike to occur in bulk regions of Solid-State devices where carriers react as dipoles against this field. The absence of the shot noise that charges drifting in resistors should produce and the evolution of the Phase Noise with the active power existing in the resonators of L-C oscillators, are two effects added in proof for this conduction model without carrier drift where the resistance of any two-terminal device becomes discrete and has a minimum value per carrier that is the Quantum resistance RK/(2pi)

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Num ambiente como o da Galiléia do século I, onde o ensino era realizado nas comunidades religiosas, vilarejos e núcleos familiares de forma oral, o método de fixação de ensinos mediante a assimilação de símbolos do cotidiano era fundamental. Por conta disso, acreditamos que, dentre as fontes orais ou escritas preservadas e organizadas pelos Evangelhos Sinóticos, as parábolas de Jesus compõem o gênero literário mais original por terem sido preservadas na memória, com maior precisão pelos primeiros seguidores de Jesus. Muitos estudiosos empreenderam importantes trabalhos para pesquisar o lugar social das parábolas de Jesus, a maioria deles partindo dos próprios textos dispostos como estão nos Evangelhos. Neste trabalho, nos propomos trabalhar as parábolas de Jesus como ditos bem preservados pela oralidade a partir da teoria da Fonte Q, que é tratada como um dos estratos mais primitivos da tradição formativa dos Evangelhos Sinóticos e do movimento de Jesus. As parábolas do Ladrão (Q 12,39-40), Servo Infiel (Q 12,42-46) e do Dinheiro Confiado (Q 19,12-27) sempre foram vistas pela tradição eclesial como parábolas que tratam da necessária vigilância do cristão por conta da repentina parusia de Jesus. No entanto, nesse trabalho vamos além, pois acreditamos que essas parábolas tratam do contexto social da Galiléia do século I, onde são retratadas a opressão econômica e a violência social imposta aos pequenos proprietários e camponeses empobrecidos.(AU)

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Num ambiente como o da Galiléia do século I, onde o ensino era realizado nas comunidades religiosas, vilarejos e núcleos familiares de forma oral, o método de fixação de ensinos mediante a assimilação de símbolos do cotidiano era fundamental. Por conta disso, acreditamos que, dentre as fontes orais ou escritas preservadas e organizadas pelos Evangelhos Sinóticos, as parábolas de Jesus compõem o gênero literário mais original por terem sido preservadas na memória, com maior precisão pelos primeiros seguidores de Jesus. Muitos estudiosos empreenderam importantes trabalhos para pesquisar o lugar social das parábolas de Jesus, a maioria deles partindo dos próprios textos dispostos como estão nos Evangelhos. Neste trabalho, nos propomos trabalhar as parábolas de Jesus como ditos bem preservados pela oralidade a partir da teoria da Fonte Q, que é tratada como um dos estratos mais primitivos da tradição formativa dos Evangelhos Sinóticos e do movimento de Jesus. As parábolas do Ladrão (Q 12,39-40), Servo Infiel (Q 12,42-46) e do Dinheiro Confiado (Q 19,12-27) sempre foram vistas pela tradição eclesial como parábolas que tratam da necessária vigilância do cristão por conta da repentina parusia de Jesus. No entanto, nesse trabalho vamos além, pois acreditamos que essas parábolas tratam do contexto social da Galiléia do século I, onde são retratadas a opressão econômica e a violência social imposta aos pequenos proprietários e camponeses empobrecidos.(AU)

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The RNA phage Qβ requires for the replication of its genome an RNA binding protein called Qβ host factor or Hfq protein. Our previous results suggested that this protein mediates the access of replicase to the 3′-end of the Qβ plus strand RNA. Here we report the results of an evolutionary experiment in which phage Qβ was adapted to an Escherichia coli Q13 host strain with an inactivated host factor (hfq) gene. This strain initially produced phage at a titer ≈10,000-fold lower than the wild-type strain and with minute plaque morphology, but after 12 growth cycles, phage titer and plaque size had evolved to levels near those of the wild-type host. RNAs isolated from adapted Qβ mutants were efficient templates for replicase without host factor in vitro. Electron microscopy showed that mutant RNAs, in contrast to wild-type RNA, efficiently interacted with replicase at the 3′-end in the absence of host factor. The same set of four mutations in the 3′-terminal third of the genome was found in several independently evolved phage clones. One mutation disrupts the base pairing of the 3′-terminal CCCoh sequence, suggesting that the host factor stimulates activity of the wild-type RNA template by melting out its 3′-end.

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The ab initio structures of 2,7,9-tricarboxypyrroloquinoline quinone (PQQ), semiquinone (PQQH), and dihydroquinone (PQQH2) have been determined and compared with ab initio structures of the (PQQ)Ca2+, (PQQH)Ca2+, and (PQQH2)Ca2+ complexes as well as the x-ray structure of (PQQ)Ca2+ bound at the active site of the methanol dehydrogenase (MDH) of methyltropic bacteria. Plausible mechanisms for the MDH oxidation of methanol involving the (PQQ)Ca2+ complex are explored via ab initio computations and discussed. Considering the reaction of methanol with PQQ in the absence of Ca2+, nucleophilic addition of methanol to the PQQ C-5 carbonyl followed by a retro-ene elimination is deemed unlikely due to large energy barrier. A much more favorable disposition of the methanol C-5 adduct to provide formaldehyde involves proton ionization of the intermediate followed by elimination of methoxide concerted with hydride transfer to the oxygen of the C-4 carbonyl. Much the same transition state is reached if one searches for the transition state beginning with Asp-303–CO2−general-base removal of the methanol proton of the (PQQ)Ca2+O(H)CH3 complex concerted with hydride transfer to the oxygen at C-4. For such a mechanism the role of the Ca2+ moiety would be to (i) contribute to the formation of the ES complex (ii) provide a modest decrease in the pKa of methanol substrate,; and (iii) polarize the oxygen at C-5.