One new pyrroline compound from Callistemon viminalis (Sol. Ex Gaertner) G.Don Ex Loudon.

One new compound: 3,4-dihydro-2-(hydroxymethyl)-4-methyl-2H-pyrrol-2-ol (5) was isolated from the fruits and bark of Callistemon viminalis along with the known compounds lupeol (1), octacosanol (2), ß-sitosterol (3), betulin (4), betulinic acid (6), ursolic acid (7), corosolic acid (8), ß-sitosterol-3-O-ß-D-glucoside (9), methyl gallate (10), gallic acid (11), catechin (12), ellagic acid (13) and 3-O-acetylursolic acid (14) (compound 14 was isolated from the bark and not detected in the fruits). Structures of these compounds were elucidated on the basis of their spectroscopic data (NMR, MS, IR spectra and COSY and HR-MS for 5a). The antioxidant activity of the total extracts, petroleum ether, CH2Cl2 and EtOAc fractions together with the compounds 6, 7, 9, 10, 11, 12 and 13 was comparable with that of the standard antioxidant, ascorbic acid.

Maxillofacial cone beam computed tomography: essence, elements and steps to interpretation.

Maxillofacial cone beam computed tomography (CBCT) is one of the most significant advances in dental imaging since rotational panoramic radiography. While the acquisition of CBCT data is technically simple, numerous parameters should be considered so that CBCT imaging is performed appropriately and 'task specific'. This involves an understanding of not only exposure (e.g. geometric and software parameters to minimize patient dose, while sustaining diagnostic image quality) but also image formatting options to maximize image display. CBCT images contain far more detailed information of the maxillofacial region than do panoramic or other 2-D images and necessitate a thorough knowledge of the 3-D anatomy of the region and considerations of variability in the range of the anatomically normal. These principles, procedures and protocols, together with the interpretation of CBCT images form the basis of best practices in maxillofacial CBCT imaging. This communication aims to provide: (1) an overview of the fundamental principles of operation of maxillofacial CBCT technology; (2) an understanding of 'task specific' equipment, image selection and image display modes; and (3) a systematic methodology for sequencing interpretation of CBCT images.