RESUMEN
A novel method for increasing diffraction efficiency of transmission gratings is proposed. In this method, dielectric multilayers are inserted between a grating region and a substrate. These multilayers work as an anti-reflection coating for the transmission grating. It is presented that a grating with 1740 grooves/mm has the diffraction efficiency over 99% using this anti-reflection coating.
RESUMEN
We report the results of our studies on the selection of the quantum path in high-harmonic generation (HHG) with a relative-phase-locked two-color laser field. It is shown that by tuning the relative phase between fundamental and second-harmonic fields, The timing of tunnel ionization and subsequent electron trajectories on the sub-cycle time scale can be controlled. We have clearly observed a phase-dependent two-step feature in the harmonic spectra that can be attributed to the selection of two major trajectories in the two-color field HHG.
Asunto(s)
Color , Modelos Teóricos , Teoría Cuántica , Simulación por Computador , Luz , Dispersión de RadiaciónRESUMEN
We report on the development of an optical parametric chirpedpulse amplifier at a 1-kHz repetition rate with a 5.5-fs pulse duration, a 2.7-mJ pulse energy and carrier-envelope phase-control. The amplifier is pumped by a 450-nm pulse from a frequency-doubled Ti:sapphire laser.
Asunto(s)
Amplificadores Electrónicos , Diseño Asistido por Computadora , Rayos Láser , Modelos Teóricos , Oscilometría/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Simulación por Computador , Diseño de Equipo , Análisis de Falla de EquipoRESUMEN
We demonstrate an optical parametric chirped-pulse amplification (OPCPA) system with the pulse energy of 1.5 mJ at a 1 kHz repetition rate. The newly developed 100 ps Ti:sapphire pump laser system, which was optically synchronized with OPCPA seed pulses, delivered 10 mJ, 400 nm pump pulses. After three-stage parametric amplification, recompression of the amplifier output from 45 ps to 6.4 fs was performed. The pulse width of 6.4 fs is, to our knowledge, the shortest ever obtained by OPCPA, and the average power of 1.5 W (1.5 mJ, 1 kHz) is believed to be the highest among few-cycle OPCPA systems.
RESUMEN
In this study, the xyn3 gene from the filamentous mesophilic fungus Trichoderma reesei (Hypocrea jecorina) PC-3-7 was cloned and sequenced. Analysis of the deduced amino acid sequence of XYN III revealed considerable homology with xylanases belonging to glycoside hydrolase family 10. These results show that XYN III is distinguishable from XYN I and XYN II, two other T. reesei xylanases that belong to the glycosidase family 11. When xyn3 was expressed in Escherichia coli, significant activity was observed in the cell-free extract, and higher activity (13.2 U/ml medium) was recovered from the inclusion bodies in the cell debris. The sequence of the 5'-upstream region of the gene in the parent strain QM9414 is identical to that of PC-3-7, although the expression level of xyn3 in PC-3-7 has been reported to be at least 1,000 times greater than in QM9414. These results suggest that xyn3 expression in T. reesei QM9414 is silenced. The consensus sequences for ACEI, ACEII, CREI, and the Hap2/3/5 protein complex are all present in the upstream region of xyn3. Deletion analysis of the upstream region revealed that two regions containing consensus sequences for the known regulatory elements play important roles for xyn3 expression.
Asunto(s)
Endo-1,4-beta Xilanasas/genética , Endo-1,4-beta Xilanasas/metabolismo , Regiones Promotoras Genéticas/fisiología , Trichoderma/enzimología , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Endo-1,4-beta Xilanasas/química , Escherichia coli , Eliminación de Gen , Regulación Fúngica de la Expresión Génica , Datos de Secuencia Molecular , Pliegue de Proteína , Trichoderma/genéticaRESUMEN
The pulse shape and phase of isolated attosecond extreme ultraviolet (XUV) pulses with a duration of 860 asec have been determined simultaneously by using frequency-resolved optical gating based on two-photon above-threshold ionization with 28-eV photons in He. From the detailed characterization, we succeeded in shaping isolated XUV pulses on an attosecond time scale by precise dispersion control with Ar gas density or by changing the driving pulse width. These results offer a novel way to excite and observe an electron motion in atoms and molecules.
RESUMEN
A 52-year-old woman, without a history of psoriasis, developed a widespread, sterile pustular eruption on the trunk and extremities 2 days after subcutaneous injection of dexamethasone solution. Skin biopsy revealed subcorneal pustules filled with neutrophils and moderate lymphohistiocytic infiltrate with a few eosinophils in the dermis. There was no evidence of vasculitis. Patch testing showed positive pustular reactions to dexamethasone solution. Histology of this pustule also resembled that of the original eruption. To our knowledge, acute generalized exanthematous pustulosis due to corticosteroid has not been previously reported.
Asunto(s)
Dexametasona/efectos adversos , Erupciones por Medicamentos/patología , Enfermedades Cutáneas Papuloescamosas/inducido químicamente , Enfermedad Aguda , Dexametasona/administración & dosificación , Dexametasona/uso terapéutico , Diagnóstico Diferencial , Erupciones por Medicamentos/diagnóstico , Erupciones por Medicamentos/etiología , Femenino , Humanos , Inyecciones Subcutáneas , Artropatías/tratamiento farmacológico , Persona de Mediana Edad , Enfermedades Cutáneas Papuloescamosas/diagnósticoRESUMEN
We report the case of a 51-year-old Japanese man with a unique pustulosis. He had multiple erythematous plaques and numerous pinpoint pustules on the trunk and extremities resembling pustular psoriasis. Histologic features revealed a fully developed intraepidermal abscess filled with neutrophils and disrupted epidermal keratinocytes. Mild leukocytosclastic vasculitis was seen in the underlying dermis. A direct immunofluorescence study revealed IgM, Clq, C3 and fibrinogen deposits in the dermal vessels. The patient had also sternoclavicular hyperostosis. We think that this represents a unique type of pustular vasculitis distinct from pustular psoriasis.