Cytosol androgen receptor from kidney of normal and testicular feminized (Tfm) mice.

The interference pattern of two laser beams induces periodical variations of the optical properties of matter (refractive index and absorption coefficient). Induced grating structures have been observed in absorbing liquids and solids, plasmas, laser materials, dye solutions and semiconductors. These gratings have been applied to thermal diffusion measurements, excitation of high frequency normal and second sound waves, determination of electronic lifetimes, distributed feedback lasers and real-time holography. The literature on transient grating materials and applications is surveyed.

Laser-induced Grating Phenomena

The resistance of Klebsiella pneumoniae BM4493, isolated in Ho Chi Minh City, Vietnam, to cefotaxime and aztreonam was due to production of a novel β-lactamase, CTX-M-17. The blaCTX-M-17 gene was borne by 7,086-bp plasmid pIP843, which was entirely sequenced and which was found to belong to the ColE1 family. The 876-bp blaCTX-M-17 gene differed from blaCTX-M-14 by 2 nucleotides, which led to the single amino acid substitution Glu289→Lys. blaCTX-M-17 was flanked upstream by an ISEcp1-like element and downstream by an insertion sequence (IS) IS903 variant designated IS903-C. The transcriptional start site of blaCTX-M-17 was located 109 nucleotides upstream from the initiation codon in the ISEcp1-like element, which also provided the promoter sequences. Plasmid pIP843, which was non-self-transferable and nonmobilizable, contained five open reading frames transcribed in the same orientation. Regions homologous to sequences coding for putative RNA II and RNA I transcripts, a rom gene, which is involved in initiation of replication, and a cer-like gene, which is responsible for the stability of ColE1-like plasmids, were identified. Consensus sequences for putative replication (oriV) and transfer (oriT) origins were present. Results of primer extension experiments indicated that ISEcp1 provides the promoter for expression of blaCTX-M-17 and may contribute to dissemination of this gene.

ColE1-Like Plasmid pIP843 of Klebsiella pneumoniae Encoding Extended-Spectrum β-Lactamase CTX-M-17

We have observed efficient reproduction at visible wavelengths of 1.06‐μ images. We employed a phase‐matched four‐wave mixing process in which three waves at ν, ν, and ω mix to generate a fourth wave at ω, with no resonant conditions in either frequency. The image conversion was seen with each of the 14 liquids tried as a nonlinear medium and also with a glass. Thermal index changes were the dominant mechanism.

Infrared‐to‐optical image conversion by Bragg reflection from thermally induced index gratings

Characterization of a hormone receptor defect in the androgen-insensitivity mutant.

Bragg reflection of light from a phase grating has been used as a technique for the investigation of nonlinear optical phenomena A continuous argon ion laser was used to probe the structure induced in a liquid by the nonlinear interaction of a high-intensity ruby-laser beam with that liquid This arrangement had the advantage of allowing direct space and time-resolved measurements of the induced effects

Bragg reflection from a phase grating induced by nonlinear optical effects in liquids

It is postulated that in a saturable dye absorber used for giant pulse laser switching a phase grating is formed. To prove this experimentally a frequency doubled part of the laser beam was reflected from this ``Lippman plate'' at the Bragg angle.

Bragg reflection of laser light from a phase grating in a q‐switching liquid

THE amplification of light signals by a material in an inverted state depends on the gain profile of the amplifying medium and the spectrum of the incoming signal. The fundamental light amplification processes suggest that if a Gaussian (or Lorentzian) shaped narrow spectrum signal is amplified by a wide linewidth amplifier whose line centre does not coincide with that of the signal, frequency shifts occur during the amplification process. In this letter we report a direct experimental observation of a frequency shift occurring during the amplification of a narrow spectrum signal by an amplifier of wide linewidth. The ability of trivalent neodymium to serve as the active ion in different host materials provided us with the necessary experimental conditions because the spectra of the different systems do not coincide exactly.

Observation of a Frequency Shift during the Amplification of a Narrow Spectrum Light Signal

A general theory is presented which describes stimulated scattering, in a liquid medium, in terms of the refractive index modulation induced in the medium by the strong electric fields of the laser and scattered beams. It is shown that this modulation also results in the Bragg reflexion of low-power light of other frequencies incident on the scattering region. Results are presented which indicate that this Bragg reflexion affords a convenient technique for the comprehensive investigation of the modulation.

Stimulated Scattering and Induced Bragg Reflexion of Light in Liquid Media. I. Theoretical

Blue fluorescence has been observed from saturable absorbers excited by ruby laser light. The intensity dependence of this fluorescence showed that it was a result of excited-state absorption to the second single state. This intensity dependence also indicated the power density required to saturate the first excited singlet state for each dye. A similar fluorescence due to two photon absorption was observed in certain solvents.

V. I. Little

Papers

Bragg reflection from a phase grating induced by nonlinear optical effects in liquids

Bragg reflection of laser light from a phase grating in a q‐switching liquid

Observation of a Frequency Shift during the Amplification of a Narrow Spectrum Light Signal

Stimulated Scattering and Induced Bragg Reflexion of Light in Liquid Media. I. Theoretical

Fluorescence due to excited state absorption in saturable absorbers