objective: the clavulanic acid regulatory gene (clar) is in the clavulanic acid biosynthetic gene cluster that encodes clar. this protein is a putative regulator of the late steps of clavulanic acid biosynthesis. the aim of this research is the molecular cloning of clar, isolated from the iranian strain of streptomyces clavuligerus (s. clavuligerus). materials and methods: in this experimental ...

In vitro studies were conducted to identify the hepatic cytochrome P450 (CYP) protein(s) involved in the oxidative metabolism of [14C]clarithromycin (CLAR) in the presence of native human liver microsomes. The identity of the two major CLAR metabolites present in microsome incubates, 14-(R)-hydroxy-CLAR and N-desmethyl-CLAR, was confirmed by MS. Over the CLAR concentration range of 1.0-140 micr...

It is shown that the Clar number can be arbitrarily larger than the cardinality of a maximal alternating set. In particular, a maximal alternating set of a hexagonal system need not contain a maximum cardinality resonant set, thus disproving a previously stated conjecture. It is known that maximum cardinality resonant sets and maximal alternating sets are canonical, but the proofs of these two ...

the clar of streptomyces clavuligerus in the clavulanic acid gene cluster encodes a transcriptional regulator that controls clavulanic acid biosynthesis. the main goal of this study was isolation and molecular detection of the clar gene and its cloning in the streptomyces specific vector (pma:: hyg). by cinsideration of the clar gene’s start codon, the specific primers were designed. after geno...

The Clar aromatic sextet theory predicts that the intensity of cyclic conjugation in chevron-type benzenoid hydrocarbons monotonically decreases along the central chain. This regularity has been tested by means of several independent theoretical methods (by the energy effects of the respective sixmembered rings, as well as by their HOMA, NICS, and SCI values, calculated at the B3LYP/6-311G(d,p)...

Classical logic based argumentation (ClAr) characterises single agent non-monotonic reasoning and enables distributed nonmonotonic reasoning amongst agents in dialogues. However, features of ClAr that have been shown sufficient to ensure satisfaction of rationality postulates, preclude their use by resource bounded agents reasoning individually, or dialectically in real-world dialogue. This pap...

The aim of this study was to investigate the effect of metronidazole resistance (MtzR) and clarithromycin resistance (ClaR) on the eradication rate for omeprazole, clarithromycin, and metronidazole triple-therapy regimen and on the development of posttherapy drug resistance in a region of high rates of MtzR. One hundred ninety-six Helicobacter pylori isolates were recovered from patients with d...

We provide an optimality criteria for a perfect matching with respect to the Clar problem in 2-connected plane bipartite graphs.

Canadian scientists and engineers are developing a prototype radio telescope using a novel concept that will permit very large aperture antennas to be constructed at a fraction of current costs. At a diameter of about 200 m, the Canadian Large Adaptive Reflector (CLAR) will be the largest fully steerable radio telescope in the world. At short cm wavelengths it will yield a factor of four improv...