introdouction: dentinal hypersensitivity (dh) is one of the most painful chronic problems reported in dental offices. various methods have been applied for the treatment of dh. however, majority of them are either ineffective or last for a short period of time. it has been reported that lasers, particularly neodymium- doped: yttrium aluminum garnet laser (nd: yag), can be helpful in the treatme...

Causal powers, say, an electron’s power to repel other electrons, are had in virtue of having properties. Electrons repel other electrons because they are negatively charged. One’s views about causal powers are shaped by—and shape—one’s views concerning properties, causation, laws of nature and modality. It is no surprise, then, that views about the nature of causal powers are generally embedde...

Over 100 μW of continuous-wave tunable ultraviolet radiation at 370 nm is generated by the sum-frequency mixing of radiation from two extended-cavity laser diodes having powers of 60 mW at 822 nm and 8 mW at 671 nm in a lithium iodate crystal. The crystal is placed in an external cavity that enhances the powers of two fundamental beams simultaneously by approximately 40. This light source is su...