Influence of 4,4'-azobis (4-cyanopentanoic acid) in Transmission and Reflection Gratings Stored in a PVA/AA Photopolymer.

Holographic transmission gratings with a spatial frequency of 2658 lines/mm and reflection gratings with a spatial frequency of 4553 lines/mm were stored in a polyvinyl alcohol (PVA)/acrylamide (AA) based photopolymer. This material can reach diffraction efficiencies close to 100% for spatial frequencies about 1000 lines/mm. However, for higher spatial frequencies, the diffraction efficiency decreases considerably as the spatial frequency increases.

Identification of a cluster of HIV-1 controllers infected with low replicating viruses.

Long term non-progressor patients (LTNPs) are characterized by the natural control of HIV-1 infection. This control is related to host genetic, immunological and virological factors. In this work, phylogenetic analysis of the proviral nucleotide sequences in env gene from a Spanish HIV-1 LTNPs cohort identified a cluster of 6 HIV-1 controllers infected with closely-related viruses.

Analysis of holographic reflection gratings recorded in polyvinyl alcohol/acrylamide photopolymer.

Holographic reflection gratings in a polyvinyl alcohol/acrylamide based photopolymer were stored using symmetrical geometry in three different thicknesses of the material. The advantage of symmetrical geometry is that exact expressions for transmittance, reflectance, and electric fields can be obtained analytically. Using these expressions, experimental data were fitted to obtain parameters such as refractive index modulation, spatial period of the grating, optical thickness or shrinkage of the material.

Study of reflection gratings recorded in polyvinyl alcohol/acrylamide-based photopolymer.

High-spatial-frequency fringes associated with reflection holographic optical elements are difficult to obtain with currently available recording materials. In this work, holographic reflection gratings were stored in a polyvinyl alcohol/acrylamide photopolymer. This material is formed of acrylamide photopolymer, which is considered interesting material for optical storage applications such as holographic memories.

A dual superinfection and recombination within HIV-1 subtype B 12 years after primoinfection.

To analyze superinfection in an HIV-1-infected patient showing high-risk practices, viral quasispecies were analyzed in pol and env genes in several plasma samples. Phylogenetic analysis in the reverse transcriptase fragment in pol gene identified a single virus in the first 3 samples analyzed, but 12 years after primoinfection, 3 different viral strains were detected in the patient quasispecies. This result suggests a superinfection with 2 HIV-1 strains, one of which showed the T215Y + M184V resistance mutations.