Abstract: A bio-degenerable bone cement is made of a mixture of poly (propylene fumarate) (PPF) and a diphasic material of tetra-calcium phosphate (TTCP)/dicalcium phosphate anhydrous (DCPA). The bone cement produced by a manufacturing method is injectable, bio-degenerable and non-penetrable to radioactive rays and features the advantages of a compressive strength close to the strength of bones, a low polymerization temperature, and a high biological compatibility.

Abstract: A diving mask with a drain port on the lower front of a nose on the frame body of the mask. A flow guide tube is connected to the drain port and bent toward the lower edge of the nose. The flow guide tube of the drain port is provided with a check drain valve which uses the flow guide action of the flow guide tube to smoothly guide the water and the air blown out by the diver so that it flows to the lower edge of the diving mask without water diffusion. The diving mask also includes a fixing cover to cover the flow guide tube and nose so that the flow guide tube can be stably engaged with the nose.