BACKGROUND Uracil derivatives have a great attraction because they play an important role in pharmacological activities. Pyrimidodiazepines, lumazines, triazolopyrimidines and xanthines have significant wide spectrum activities including anticancer, antiviral as well as antimicrobial activities. RESULTS A newly synthesized compounds pyrimido[4,5-b][1, 4]diazepines 5a-e, 6a-d, lumazines 7a-d, ...

The title trihalogenated nitro-benzene derivatives, C6H2Br3NO2 and C6H2Br2INO2, crystallize in triclinic and monoclinic cells, respectively, with two mol-ecules per asymmetric unit in each case. The asymmetric unit of the tri-bromo compound features a polarized Br(δ+)⋯Br(δ-) inter-molecular halogen bond. After substitution of the Br atom in the para position with respect to the nitro group, the...

We address the problem of egomotion estimation for a monocular observer moving under arbitrary translation and rotation, in an unknown environment. The method we propose is uniquely based on the spatio-temporal image derivatives, or the normal ow. We introduce a search paradigm which is based on geometric properties of the normal ow eld, and consists in considering a family of search subspaces ...

background : thymol and carvacrol have previously demonstrated larvicidal activity against aedes aegypti (diptera: culicidae). in view of this fact, it was of our interest to obtain synthetic derivatives and evaluate their larvicidal ac­tivity on ae. aegypti larvae. methods : structural modifications were performed on thymol and carvacrol in an effort to understand the functional groups necessa...

4-Carbethoxy-1-methyl-2-phenacyl-3-phenylpyrrole (9), 4-carbethoxy-2-(4-methoxybenzoyl)-3-(4-methoxyphenyl)pyrrole (10) and 2-(4-methoxybenzoyl)-3,4-bis-(4-methoxyphenyl)pyrrole (11) proved to be potent cytotoxic agents against the growth of murine and human leukemias and lymphomas. Selective toxicity was demonstrated against the growth of solid tumors, e.g., human adenocarcinoma of the colon S...

diazotization of 3-amino-2-cmoro pyridine (3) in the presence of dithizone (5) gave dphenyl-2-phenylazo-4h-pyrid[o3 ,2-e] [1,3,4] thiadiazine (6). reaction of 2- chloro-3-nitropyridine (2, g=h) with (5) dfordd 4-phenyl -2-phenylazo -4hpyrido [2,3-el [1,3,4] thiadiazine (7). reduction of the latter with h gas in the presence of raney nickel gave the corresponding amino derivative (12). one pot c...

6-methyl- 1,2,4-triazine-3-(2h)-selenone-5(4h)-one(l) reacts in the presence of base with phenacyl bromide to give a mixture of compounds (2) and (3). this mixture is dehydrated in the presence of h,so, to give 3-phenyl-6 methyl-7h-selenazolo[3,2-b] [i ,2,4] triazin-7-one (6). for careful structure assignment of (6) its regioisomer 3-methyl-6-phenyl-4h-selenazolo [2,3-c] [ 1,2,4] triazin-4-one ...

In the presence of an alkene, three different modes of photocycloaddition with benzene derivatives can occur; the [2 + 2] or ortho, the [3 + 2] or meta, and the [4 + 2] or para photocycloaddition. This short review aims to demonstrate the synthetic power of these photocycloadditions.

In this paper it is shown how to perform hand-eye calibration using only the normal flow field and knowledge about the motion of the hand. The proposed method comprise a simple way to calculate the handeye calibration when a camera is mounted on a robot. Firstly, it is shown how the orientation of the optical axis can be estimated from at least two different translational motions of the robot. ...

This paper presents a new technique to the instantaneous 3D motion estimation. The main contributions are as follows. First, we show that the 3D camera or scene velocity can be retrieved from image derivatives only assuming that the scene contains a dominant plane. Second, we propose a new robust algorithm that simultaneously provides the Least Trimmed Square solution and the percentage of inli...