Integrase (IN), an essential enzyme of human immunodeficiency virus (HIV),

When a femtosecond laser pulse is focused inside a transparent material, the optical intensity in the focal volume can become high enough to induce permanent structural modifications such as a refractive index change or the formation of a small vacancy. Thus, one can micromachine structures inside the bulk of a transparent material in three dimensions. We review the mechanisms of and techniques for bulk modification of transparent materials using femtosecond laser pulses and discuss the fabrication of photonic and other structures in transparent materials, including waveguides, couplers, gratings, diffractive lenses, optical data storage, and microfluidic channels.

The viral enzyme integrase is essential for the replication of human immunodeficiency virus type 1 (HIV-1) and represents a remaining target for antiretroviral drugs. Here, we describe the modification of a quinolone antibiotic to produce the novel integrase inhibitor JTK-303 (GS 9137) that blocks strand transfer by the viral enzyme. It shares the core structure of quinolone antibiotics, exhibits an IC50 of 7.2 nM in the strand transfer assay, and shows an EC50 of 0.9 nM in an acute HIV-1 infection assay.

Subcellular organelles in living cells were inactivated by tightly focusing femtosecond laser pulses inside the cells. Photodisruption of a mitochondrion in living cells was experimentally confirmed by stacking three-dimensional confocal images and by restaining of organelles. The viability of the cells after femtosecond laser irradiation was ascertained by impermeability of propidium iodide as well as by the presence of cytoplasmic streaming.

By moving silica glass in a preprogrammed structure, we directly produced three-dimensional holes with femtosecond laser pulses in single step. When distilled water was introduced into a hole drilled from the rear surface of the glass, the effects of blocking and redeposition of ablated material were greatly reduced and the aspect ratio of the depth of the hole was increased. Straight holes of 4-mu;m diameter were more than 200 microm deep. Three-dimensional channels can be micromachined inside transparent materials by use of this method, as we have demonstrated by drilling a square-wave-shaped hole inside silica glass.

Background: Propolis has been used worldwide as a dietary supplement to maintain and improve human health. We examined whether ethanol extracts of Brazilian propolis exhibit antiviral activity against influenza virus in vitro and in vivo. Methods: Among 13 ethanol extracts screened in a plaque reduction assay, four showed anti-influenza virus activity. The anti-influenza efficacy of the four extracts was further examined in a murine influenza virus infection model. The mice were infected intranasally with influenza virus, and the four extracts were orally administered at 10 mg/kg three times daily for seven successive days after infection. Results: In this infection model, only one extract, AF-08, was significantly effective at 10 mg/kg in reducing the body weight loss of infected mice. The doses of 2 and 10 mg/ kg were also effective in prolonging the survival times of infected mice significantly, but 0.4 mg/kg was not. The antiinfluenza efficacy of AF-08 at 10 mg/kg was confirmed in a dose-dependent manner in mice. AF-08 at 10 mg/kg significantly reduced virus yields in the bronchoalveolar lavage fluids of lungs in infected mice as compared with the control. The reduction of virus yields by AF-08 at 10 mg/kg significantly corresponded to those induced by oseltamivir at 1 mg/kg twice daily from day 1 to day 4 after infection. Conclusion: The Brazilian propolis AF-08 was indicated to possess anti-influenza virus activity and to ameliorate influenza symptoms in mice. AF-08 may be a possible candidate for an anti-influenza dietary supplement for humans.

We fabricated a terahertz wire-grid polarizer consisting of a micrometer-pitch Al grating on a Si substrate by photolithography and wet etching. The ratio of TM and TE transmittances (extinction ratio) was over 35 dB at 0.5 THz. At the Brewster angle of the Si substrate, the polarization transmittance of a TM wave through the fabricated polarizer exceeded 95% and the extinction ratio was over 45 dB at approximately 1 THz. The fabricated polarizer has a higher extinction ratio than conventional free-standing terahertz wire-grid polarizers.

We report on laser welding between transparent materials without the insertion of intermediate layers such as glue by use of near-infrared femtosecond laser pulses. When femtosecond laser pulses are focused at the interface of transparent materials, the material around the focal point is melted and resolidified because of the temperature increases due to the localized nonlinear absorption of optical pulse energy. We experimentally succeeded in laser welding between two pieces of silica glass without the insertion of an intermediate layer by femtosecond laser pulses. This technique has a possible application to the joining of semiconductors such as silicon crystals.