BBC

Sound and ultrasound - Edexcel

Ultrasound close ultrasoundSound with a frequency greater than 20,000 Hz (20 kHz). waves have a frequency higher than the upper limit for human hearing – above 20,000 Hertz (Hz). Different species of ...
BBC

Sound waves - AQA Ultrasound

Ultrasound close ultrasoundSound with a frequency greater than 20,000 Hz (20 kHz). waves have a frequency higher than the upper limit for human hearing - above 20,000 Hertz (Hz). Different species of ...
Nature

Stimulation of adult resident cardiac progenitor cells by durable myocardial expression of thymosin beta 4 with ultrasound-targeted microbubble delivery

It has been proposed that thymosin beta 4 (TB4)-protein delivery stimulates differentiation of resident adult WT1-positive cardiac progenitor cells, but with very low efficiency. We determined whether ...
The Daily Signal

Fact Check: ‘There Is No Such Thing as a Heartbeat at 6 Weeks,’ Says Stacey Abrams

Ben Johnson is senior reporter and editor at The Washington Stand. Stacey Abrams, the Democratic candidate for governor of Georgia, denied that unborn children have a heartbeat at six weeks and that ...