Influence of the 6^1S_0-6^3P_1 Resonance on Continuous Lyman-alpha Generation in Mercury

Continuous coherent radiation in the vacuum-ultraviolet at 122 nm (Lyman-alpha) can be generated using sum-frequency mixing of three fundamental laser beams in mercury vapour. One of the fundamental beams is at 254 nm wavelength, which is close to the 6^1S_0-6^3P_1 resonance in mercury. Experiments have been performed to investigate the effect of this one-photon resonance on phasematching, absorption and the nonlinear yield. The efficiency of continuous Lyman-alpha generation has been improved by a factor of 4.5.Comment: 8 pages, 7 figure

Peculiarities of sub-barrier fusion with quantum diffusion approach

With the quantum diffusion approach the unexpected behavior of fusion cross section, angular momentum, and astrophysical S-factor at sub-barrier energies has been revealed. Out of the region of short-range nuclear interaction and action of friction at turning point the decrease rate of the cross section under the barrier becomes smaller. The calculated results for the reactions with spherical nuclei are in a good agreement with the existing experimental data.Comment: 11 pages, 5 figure

Avaliação da suplementação de vitamina A nas características seminais em reprodutores suínos Assessment of vitamin A supplementation on boar semen characteristics

Avaliou-se o efeito da suplementação de vitamina A na dieta sobre as características seminais (volume, motilidade, pH, vigor e concentração espermática, número total de espermatozoides, percentual de espermatozoides vivos e anormalidades morfológicas) de reprodutores suínos no período de um ano (junho de 2004 a junho de 2005). Utilizaram-se dez reprodutores híbridos com 328,5 ± 2,12 dias de idade e 191,0 ± 12,0 kg distribuídos em duas rações, uma controle, com 10.000 UI de vit. A por kg de ração por dia, e outra com 16.000 UI de vit. A, fornecidas na quantidade de 2,5 kg/dia. O delineamento foi inteiramente casualizado com medidas repetidas no tempo. Não houve efeito significativo da suplementação de vitamina A na dieta nem de interação com o tempo nas características seminais estudadas. O tempo teve efeito significativo no pH, na concentração espermática, no número total de espermatozoides, no percentual de espermatozoides vivos, nas anormalidades morfológicas, na motilidade e no vigor espermático. Apesar da não-significância da suplementação de vitamina A, foi possível detectar diferenças numéricas no aumento da motilidade e de espermatozoides vivos, bem como na diminuição das anormalidades morfológicas, resultados que indicam ação da vitamina A.<br>The objective of this study was to evaluate the effect of vitamin A feed supplementation on the following boar semen characteristics: volume, motility, vigor, seminal pH, spermatic concentration, total number of spermatozoa, percentage of living sperm cells and morphologic abnormalities. The experiment was carried out with 10 hybrid boars (328.5 ± 2.12 days of age and 191.0 ± 12.0 kg live weight). The boars were separated into two treatments and fed with two vitamin A levels: control, 10.000 UI/kg feed daily; and vitamin A, 16.000 UI. The boars received 2.5 kg feed daily. A randomized complete design was used with replication measurements in time. There was no significant effect of vitamin A supplementation on the characteristics studied, and nor on the time and treatment interaction. The was significant effect of time on pH, spermatic concentration, total number of spermatozoa, percentage of living sperm cells, morphologic abnormalities, motility and vigor. Although detect significant differences were not detected between both treatments, numerical differences were detected indicating that vitamin A influenced the average increase in motility and the percentage of living sperm cells and the reduction in the percentage of morphologic abnormalities. Data showed support the idea that vitamin A is intimately associated with spermatogenesis

The management of acute necrotizing encephalitis: a review of 369 cases

SCOPUS: ar.jinfo:eu-repo/semantics/publishe