We devise a statistical framework for edge detection by performing a statistical analysis of zero crossings of the second derivative of an image. This analysis enables us to estimate at each pixel of an image the probability that an edge passes through the pixel. We present a statistical analysis of the Lindeberg operators that we use to compute image derivatives. We also introduce a confidence...

A new two-dimensional (2D) carbon crystal, different from graphene, has been prepared from 1,3,5-trihydroxybenzene, consisting of 4-carbon and 6-carbon rings in 1:1 ratio, named 4-6 carbophene by authors, in which all carbon atoms possess sp2 hybrid orbitals with some distortion, forming an extensive conjugated π-bonding planar structure. The angles between the three σ-bonds of the carbon sp2 o...

a spectrophotometric method is used to determine the acidity constants of some derivatives of 9,10-anthraquinone in binary methanol-water mixtures at 25 °c. there is a linear inverse relationship between pka of all acids and the mole fraction of methanol in the mixed solvent. the influence of substituents in the molecular structure on the ionization constants is discussed.

quercetin, a ubiquitous flavonol, represents a promising leading drug for development of new chemotherapeutic agents. however, its limited cytotoxicity to cancer cells hampers its clinical use. in order to obtain novel quercetin derivatives with superior cytotoxicity, seven alkylated quercetin derivatives were synthesized. solubility of these derivatives was determined by turbidimetry. cytotoxi...

a series of new hexahydroquinoline and 1,4-dihydropyrimidine derivatives were synthesized. condensation of 2-methyl- thiazole-4-carboxaldehyde (1) with 1,3-cyclohexanedione and alkyl 3- aminocrotonate afforded 4-(2-methyl-thiazol-4-yl)-hexahydroquinoline while condensation of aldehyde (1) with benzoyl acetone and thiourea gave 1,4-dihydropyrimidine derivatives. the stereochemistry of 1,4-dihydr...

accurate quantum chemical computations based on density functional theory (dft) were performed on the series of 2-(4-(naphthalen-2-yl)-1,2,3-thiadiazol-5-ylthio)-n-acetamide (tta) derivatives. the local reactivity of the acetamide derivatives as anti-hiv drugs were studied in terms of fukui functions in the framework of dft. the results based on the basis set superposition error (bsse) correcti...