Artificial heart newer versions, such as the Heartmate II, developed by The Texas Heart Institute of Houston, provide continuous flow. These pumps (which may be centrifugal or axial flow) are smaller and potentially more durable and last longer than the current generation of total heart replacement pumps. Another major advantage of a VAD is that the patient keeps the natural heart, which may still function for temporary back-up support if the mechanical pump were to stop. This may provide enough support to keep the patient alive until a solution to the problem is implemented. In August 2006, an artificial heart was implanted
Human artificial chromosome artificial chromosome vectors. The first is to create a small minichromosome by altering a natural human chromosome. This is accomplished by truncating the natural chromosome, followed by the introduction of unique genetic material via the Cre-Lox system of recombination. The second method involves the literal creation of a novel chromosome "de novo". Progress regarding "de novo" HAC formation has been limited, as many large genomic fragments will not successfully integrate into "de novo" vectors. Another factor limiting "de novo" vector formation is limited knowledge of what elements are required for construction, specifically centromeric sequences. A 2009 study has shown additional