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[en] ATP synthase, H+ transporting, mitochondrial F1 complex, δ subunit (ATP5F1D; formerly ATP5D) is a subunit of mitochondrial ATP synthase and plays an important role in coupling proton translocation and ATP production. Here, we describe two individuals, each with homozygous missense variants in ATP5F1D, who presented with episodic lethargy, metabolic acidosis, 3-methylglutaconic aciduria, and hyperammonemia. Subject 1, homozygous for c.245C>T (p.Pro82Leu), presented with recurrent metabolic decompensation starting in the neonatal period, and subject 2, homozygous for c.317T>G (p.Val106Gly), presented with acute encephalopathy in childhood. Cultured skin fibroblasts from these individuals exhibited impaired assembly of F1FO ATP synthase and subsequent reduced complex V activity. Cells from subject 1 also exhibited a significant decrease in mitochondrial cristae. Knockdown of Drosophila ATPsynδ, the ATP5F1D homolog, in developing eyes and brains caused a near complete loss of the fly head, a phenotype that was fully rescued by wild-type human ATP5F1D. In contrast, expression of the ATP5F1D c.245C>T and c.317T>G variants rescued the head-size phenotype but recapitulated the eye and antennae defects seen in other genetic models of mitochondrial oxidative phosphorylation deficiency. Our data establish c.245C>T (p.Pro82Leu) and c.317T>G (p.Val106Gly) in ATP5F1D as pathogenic variants leading to a Mendelian mitochondrial disease featuring episodic metabolic decompensation.
[en] The energy loss of slow protons in a degenerate electron gas is calculated on the basis of the dielectric theory. The influence of various longitudinal dielectric functions is examined. Comparison with the results of the kinetic theory is made. The effect of the local-field correction on the straggling parameter is also discussed. (orig.)
[en] A relatively simple, position-sensitive particle detection system is described. The system is used in the momentum analyzer of a two-stage mass spectrometer system. The detector consists of two channelplates and a multi-anode collector. The position information is preamplified by two charge amplifiers and processed by a special purpose microprocessor system. The entire combination of detector and two-stage mass spectrometer has been tested by the measurement of the momentum distribution of the ionic fragments of the photodissociation of H+2 into H+ and H. The results of these measurements over a photon wavelength between 570 nm and 622.5 nm are presented and compared to the well-established theory of the photodissociation of H+2. (orig.)
[en] Experimental measurements of double differential cross sections were obtained for the ionization of He thorugh the impact of H+ and He2+3 at intermediate energies (50-100 KeV/amu). (A.C.A.S.)
[pt]Realizaram-se medidas experimentais de secoes eficazes duplamente diferenciais (angulo e energia) para a ionizacao de He por impacto de H+ e He2+3 de energias intermediarias (50-100 KeV/amu). (A.C.A.S.)
[en] From H α CCD observations taken with the 4.2 m William Herschel Telescope a catalogue of 394 HII regions of the spiral NGC 3992 has been compiled. The distribution of diameters and the luminosity function for the arm and the interarm HII regions has been studied
[en] The results of R-matrix calculations on electron collisions with H2+ are presented. These calculations include the three lowest states of H2+ (2Σg+, 2Σu+ and 2Πu). Positions and widths of the Feshbach resonances converging to both the 2Σu+ and 2Πu states are given, as are autoionization branching ratios for resonances lying above the 2Σu+ state. Complex quantum defects, calculated be performing scattering calculations above threshold are presented for all three states considered. Results are tabulated for 12 symmetries (1Σg+, 1Σu+, 1Πg, 1Δg, 1Δu, 3Σg+, 3Σu+, 3Πu, 3Πg, 3Δg, 3Δu) and 13 internuclear separations from 1 to 4 a0. 17 refs., 5 tabs
[en] Simple statistical approximations for the electron pick up processes in a wide range of proton energies are presented. When v1 is comparable to the Fermi velocity but small compared to the electron velocities in the ion cores, approximately Z2/sup 2/3/v0, electron capture occurs in the tail of the electron distribution at the target surface (v0 = 2.2 . 108 cm/s). Under these conditions phi0 is nearly the same for all surfaces and depends only on v1. When v1 approaches Z2/sup 2/3/v0, electron capture is influenced primarily by the interaction of the proton with the cores of the target atoms, but the relevant cross sections depend on Z2 only as Z2/sup 1/3/, and, thus phi0 depends only slightly on Z2. When v1 exceeds Z2/sup 2/3/v0 and thus has exhausted the electron velocity space proffered to the proton beam by the target, double scattering processes are required for electron capture; phi0 then depends on v1 and strongly on Z2, to order Z23. In the light of the simplicity of the model underlying the considerations, theory and experiments are found to be in satisfactory agreement over the projectile energy range from E approximately 20 keV to E approximately 0.6 GeV, where phi0 ranges from approximately 0.6 to approximately 10-12. (U.S.)
[en] We consider the possibility that solid molecular hydrogen is present in interstellar space. If so cosmic-rays and energetic photons cause ionization in the solid leading to the formation of H+6. This ion is not produced by gas-phase reactions and its radiative transitions therefore provide a signature of solid H2 in the astrophysical context. The vibrational transitions of H+6 are yet to be observed in the laboratory, but we have characterized them in a quantum-theoretical treatment of the molecule; our calculations include anharmonic corrections, which are large. Here we report on those calculations and compare our results with astronomical data. In addition to the H+6 isotopomer, we focus on the deuterated species (HD)+3 which is expected to dominate at low ionization rates as a result of isotopic condensation reactions. We can reliably predict the frequencies of the fundamental bands for five modes of vibration. For (HD)+3 all of these are found to lie close to some of the strongest of the pervasive mid-infrared astronomical emission bands, making it difficult to exclude hydrogen precipitates on observational grounds. By the same token these results suggest that (HD)+3 could be the carrier of the observed bands. We consider this possibility within the broader picture of interstellar medium photo-processes and we conclude that solid hydrogen may indeed be abundant in astrophysical environments.
[en] Final state momentum distributions of the projectile, the recoil-ion, and the emitted electron in ion-atom ionizing collisions are examined. New theoretical results using the continuum distorted wave-eikonal initial state (CDW-EIS) approximation are reported for He ionization by proton impact at high and intermediate energies. The finite value at the kinematical threshold in the longitudinal recoil-ion momentum distribution is shown to be considerably enhanced at intermediate energies. The transverse recoil-ion momentum distribution is calculated by considering the internuclear interaction. At higher energies, the longitudinal and transverse electron momentum distributions clearly show the binary electron contribution. The calculations prompt for further experimental work in the field. (orig.)
[en] The cross sections for the processes H+ + Cs→H(2p and 2s) + Cs+ were calculated in the center of mass energy range 250-2400eV using a pseudo-potential formalism for the potential curves and coupling matrix elements and a perturbated stationary state formulation for the calculation of the cross sections
[fr]On calcule les sections efficaces dans le centre de masse du processus H+ + Cs→H(2p et 2s) + Cs+ pour les energies entre 250 et 2400eV en employant un formalisme pseudo potentiel pour les courbes de potentiel et les elements de matrice de couplage et une formulation d'etat stationnaire perturbe pour le calcul des sections efficaces