Objective: To evaluate root canal configuration and morphology of premolar teeth among Saudi subpopulations using cone beam computed tomography (CBCT). Material Methods: In this retrospective cross-sectional study, CBCT images 314 patients comprising 346 maxillary 412 mandibular first (FPM) teeth, 298 387 second (SPM) were analyzed to the number roots, morphology, based on Vertucci's classifica...

Branching fractions were measured for electric dipole transitions from the 5p upper levels to the 5s levels in neutral krypton atoms. The measurements were made with a wall-stabilized electric arc and a 2m monochromator for the spectral lines in the visible, and with a hollow cathode lamp and the NIST 2m–Fourier transform spectrometer for the lines in the near infrared. A semi-empirical calcula...

The synthesis of 5-cyanomethoxy-2-thiouracil (5b) is described. The acid catalysed ethanolysis of 5b leads to 5-ethoxycarbonylmethoxy-2-thiouracil (5a). Condensations of 5-methoxy-2thiouracil (5) and 5a with the sugar component 7 using the "silyl method" yield peracylated 5-methoxy-2-thiouridine (8) and 5-ethoxycarbonylmethoxy-2-thiouridine (8a), which under treatment with sodium methanolate/me...

The mol-ecule of the title compound, C(23)H(34)O(6), is built up from three fused carbocycles, one five-membered, one six-membered and one seven-membered. The five-membered ring has an envelope conformation, whereas the six-membered ring has a perfect chair conformation and the seven-membered ring has a boat conformation. Intra-molecular C-H⋯O hydrogen bonds together with van der Waals inter-ac...

we shall have the definition given by H. Weber, loo. cit. That these postulates 1, 2, 3', 4', 5a are mutually independent (when n > 2) has already been shown in the writer's previous paper (page 300). I t should be noticed, however, that postulates 1, 2, 3', 4', 56 would not be sufficient to define an infinite group, since the system of positive integers, with a o b = a + 6, satisfies them all,...

and Applied Analysis 3 Case 1. Suppose that m = 1, by equating the coefficients of Y i (i = 2, 1, 0) on both sides of (11), we have a 󸀠 1 (X) = g (X) a 1 (X) , (12a) a 󸀠 0 (X) = h (X) a 1 (X) + g (X) a 0 (X) , (12b) a 1 (X)(( 2 c − 1 )X 3 + ( w 2 − 2n − (a + cw) 2

A series of 1-(2-methyl-4-nitro-imidazol-1-yl)-3-arylaminopropan-2-ones (2a-e), 2-methyl-5-nitro-1-{2-[arylmethoxy]ethyl}-1H-imidazoles (5a-d), and N-(3-hydroxyphenyl)-2-(substituted imidazol-1-yl)alkanamides (8a-e) were synthesized with the aim to develop novel imidazole analogs with broad-spectrum chemotherapeutic properties. Title compounds were evaluated for their anti-HIV and antibacterial...

This paper presents two cases of late developing supernumerary premolars. Case 1 is a female patient with nonsyndromic multiple supernumerary teeth located in the maxillary right premolar-molar region, maxillary left premolar region, and the mandibular right and left premolar regions. In this patient surgical removal of all supernumerary teeth was carried out to avoid complications during ortho...

An efficient palladium-catalyzed tandem approach for the synthesis of highly functionalized tetrahydroquinazolines 4a–q, and 5a–f by the reaction of o-haloanilines 1a–g with acrylates 2a–d and isothiocyanates 3aa–3ah/isocyanates 3ba–3bfvia Heck-conjoined amidation/thioamidation and concomitant chemoselective Michael-addition is described. A competitive experiment showed that isothiocyanates wer...