Pre-exposure prophylaxis (PrEP) is a course of HIV drugs taken daily by HIV negative people most at risk of HIV to reduce their risk of HIV infection. Truvada is currently the only drug approved for use as PrEP. Truvada is a single pill that is a combination of two anti-HIV drugs, tenofovir and emtricitabine.
Astronomical spectroscopy is one of the most powerful tools used by astronomers to gain a fundamental understanding of our universe. Astronomical spectroscopy is a technique in which the absorption and emission of electromagnetic radiation from stars and other celestial objects are studied.he absorption and or emission spectra of a molecule generally consist of a number of lines. These lines correspond to the discrete differences in the internal energy modes of a molecule.
The Electromagnetic Spectrum. The electromagnetic (EM) spectrum is the scientific name for types of photon radiation. Electromagnetic radiation consists of photons (light particles) that travel in a wave-like pattern at the speed of light. The amount of energy found in these photons forms the various types of electromagnetic radiation in the spectrum, which is expressed in terms of energy, wavelength or frequency.