The identification and characterization of stem cells is a major focus of developmental biology and regenerative medicine.The advent of genetic inducible fate mapping techniques has made it possible to precisely label...The identification and characterization of stem cells is a major focus of developmental biology and regenerative medicine.The advent of genetic inducible fate mapping techniques has made it possible to precisely label specific cell populations and to follow their progeny over time.When combined with advanced mathematical and statistical methods,stem cell division dynamics can be studied in new and exciting ways.Despite advances in a number of tissues,relatively little attention has been paid to stem cells in the oral epithelium.This review will focus on current knowledge about adult oral epithelial stem cells,paradigms in other epithelial stem cell systems that could facilitate new discoveries in this area and the potential roles of epithelial stem cells in oral disease.展开更多
The E×B drift instability is studied in Hall thruster using one-dimensional particle in cell(PIC)simulation method.By using the dispersion relation,it is found that unstable modes occur only in discrete bands in ...The E×B drift instability is studied in Hall thruster using one-dimensional particle in cell(PIC)simulation method.By using the dispersion relation,it is found that unstable modes occur only in discrete bands in k space at cyclotron harmonics.The results indicate that the number of unstable modes increases by increasing the external electric field and decreases by increasing the radial magnetic field.The ion mass does not affect the instability wavelength.Furthermore,the results confirm that there is an instability with short wavelength and high frequency.Finally,it is shown that the electron and ion distribution functions deviate from the initial state and eventually the instability is saturated by ion trapping in the azimuthal direction.Also for light mass ion,the frequency and phase velocity are very high that could lead to high electron mobility in the axial direction.展开更多
基金the National Institutes of Health(F30-DE022509 to KBJ and R01-DE021420 to ODK)
文摘The identification and characterization of stem cells is a major focus of developmental biology and regenerative medicine.The advent of genetic inducible fate mapping techniques has made it possible to precisely label specific cell populations and to follow their progeny over time.When combined with advanced mathematical and statistical methods,stem cell division dynamics can be studied in new and exciting ways.Despite advances in a number of tissues,relatively little attention has been paid to stem cells in the oral epithelium.This review will focus on current knowledge about adult oral epithelial stem cells,paradigms in other epithelial stem cell systems that could facilitate new discoveries in this area and the potential roles of epithelial stem cells in oral disease.
文摘The E×B drift instability is studied in Hall thruster using one-dimensional particle in cell(PIC)simulation method.By using the dispersion relation,it is found that unstable modes occur only in discrete bands in k space at cyclotron harmonics.The results indicate that the number of unstable modes increases by increasing the external electric field and decreases by increasing the radial magnetic field.The ion mass does not affect the instability wavelength.Furthermore,the results confirm that there is an instability with short wavelength and high frequency.Finally,it is shown that the electron and ion distribution functions deviate from the initial state and eventually the instability is saturated by ion trapping in the azimuthal direction.Also for light mass ion,the frequency and phase velocity are very high that could lead to high electron mobility in the axial direction.
