One area in which Star Trek technology may be falling behind its real world counterpart is life extension. For example, a number of real life scientists predict we'll be able to use nanomedicine to cure aging and other diseases, making people virtually immortal (except possibly from blunt trauma). Some believe this will actually happen within the next few decades. However, I can barely find any examples of such technology in Star Trek, where people still grow old in the 24th century. I know there are Augments, but they seem to be a minority. Similarly, if transporters can rearrange matter, then why isn't there a device that resurrects a person by rearranging their molecules into a configuration such that the person is alive? I can understand why such technology is rare in the Star Trek universe; the producers probably don't want stories in which characters have the potential to live forever. But is there an in-universe explanation for the lack of such technology?