The present invention relates to novel immortalized precursor cell populations derived from embryonic stem cell populations and methods to produce such cell populations. The suture button can include a body that has a first end surface, a second end surface, and a circumferential outer surface. The present invention also relates to methods for making strained semiconductor-on-insulator layers. Then, a laser beam with a pulse width of 1 fs to 10 ps and a wavelength of 370 to 640 nm is delivered to selectively activate the amorphous portion, so that the extension region is formed with a thickness of 20 nm or less.