Transcranial Doppler (TCD), first described in 1982 [1], is a noninvasive ultrasound (US) study that involves the use of a low-frequency (â¤2 MHz) transducer probe to insonate the basal cerebral arteries through relatively thin bone windows.
Details. as.character and is.character are generic: you can write methods to handle specific classes of objects, see InternalMethods. Further, for as.character the default method calls as.vector, so dispatch is first on methods for as.character and then for methods for as.vector.
Simply put, a radical is a part or a component of a character. All Chinese characters are made up of one or more radicals. In the traditional Kangxi åº·çradical system, there are 214 radicals. Most dictionaries are arranged according to this system, although some use a modified version of it.imply put, a radical is a part or a component of a character. All Chinese characters are made up of one or more radicals. In the traditional Kangxi åº·çradical system, there are 214 radicals. Most dictionaries are arranged according to this system, although some use a modified version of it.