A chalazion is a small bump that appears on your eyelid because of a blocked oil gland.It can develop on the lower or upper eyelid, and it often disappears without treatment in about one month. chalazion is a small bump that appears on your eyelid because of a blocked oil gland.
Artist's conception of a white dwarf accreting hydrogen from a larger companion. A nova (plural novae or novas) is a cataclysmic nuclear explosion on a white dwarf, which causes a sudden brightening of the star.Novae are not to be confused with other brightening phenomena such as supernovae or luminous red novae.he recurrence interval for a nova is less dependent on the white dwarf's accretion rate than on its mass; with their powerful gravity, massive white dwarfs require less accretion to fuel an outburst than lower-mass ones.
This is, in turn, surrounded by the viral envelope, that is composed of the lipid bilayer taken from the membrane of a human host cell when the newly formed virus particle buds from the cell. The viral envelope contains proteins from the host cell and relatively few copies of the HIV Envelope protein, which consists of a cap made of three molecules known as glycoprotein (gp) 120, and a stem consisting of three gp41 molecules that anchor the structure into the viral envelope.