conclusions the results of this study phenotypically and genotypically confirmed the high frequency of esbl-producing strains, such as the ctx-m and ctx-m-1 genes, among enterobacteriaceae isolates in our region. therefore, use of antibiotic susceptibility testing for the detection of esbl isolates prior to the prescription of beta-lactam antibiotics is recommended. this could help prevent the ...

Previous studies have identified a conserved AG dinucleotide at the 3' splice site (3'SS) and a polypyrimidine (pPy) tract that are required for trans splicing of polycistronic pre-mRNAs in trypanosomatids. Furthermore, the pPy tract of the Trypanosoma brucei alpha-tubulin 3'SS region is required to specify accurate 3'-end formation of the upstream beta-tubulin gene and trans splicing of the do...

microstructural investigation of low molecular weight 1,4-polybutadiene (1,4-pbd) was studied by 1h and 13c nuclear magnetic resonance spectroscopy (nmr). the isomer contents of 1,4-cis, 1,4-trans and 1,2- vinyl in polybutadiene microstructure were determined. the number average molecular weight for low molecular weight polybutadiene was measured by nmr techniques and comparison was made with g...

The title compound, C(33)H(34)N(4)O(2)S·CH(3)OH, was prepared as a spiro-lactam ring formation of rhodamine 6 G dye for comparison with a ring-opened form. The xanthene and spiro-lactam rings are approximately planar [r.m.s. deviations from planarity = 0.122 (3) and 0.072 (6) Å, respectively]. The dihedral angles formed by the spiro-lactam and thio-phene rings with the xanthene ring system are ...

The crystal structures of the trans-fused compound potassium trans-bi-cyclo-[5.1.0]octane-4-carboxyl-ate monohydrate, K+·C9H13O2-·H2O, (I), and of cis-bi-cyclo-[5.1.0]octan-4-yl 4-bromo-benzene-sulfonate, C14H17BrO3S, (II), have been determined. Compound (I) represents the smallest trans-fused cyclo-propane structure known to date, and features the expected shortening of the bridging C-C bond r...

Infections caused by bacteria have a significant impact on public health. Chemical synthesis of new derivatives cephalexin inked to amino acid (tryptophan or histidine) through an amide bond at the acyl side chain is achieved. This new
 approach incorporating, tryptophan and histidine into primary group cephalexin, in order provide bulky very close ?-lactam ring. chemical addition act as i...

We characterized the bis-quinolizidine tetracyclic alkaloid (5S, 6S, 7R, 11R)-matrine in a supersonic jet expansion, using chirped-pulsed broadband microwave spectroscopy. Previous crystal diffraction analyses suggested 16 diastereoisomers associated with matrine's four carbon stereocenters but were inconclusive whether lactamic nitrogen atom would additionally produce separated trans-/cis- or ...

Trans-disubstituted beta-lactams show increasing utility and prominence in numerous pharmaceutical applications, making their asymmetric synthesis an attractive goal for chemists. We introduce an anionic, nucleophilic catalyst system that provides an efficient, diastereoselective route to trans-disubstituted beta-lactams, a complement to our previously described catalytic methodology for genera...

Artificial visual pigment formation from ring-demethylated retinals was studied in an effort to understand the effect that methyl groups on the chromophore cyclohexenyl ring have on the visual cycle. The stereoselective synthesis of the 11-cis-ring-demethylated analogues involves thallium-accelerated Suzuki cross-coupling reactions and highly stereocontrolled Wittig reactions to form key bonds....

Previous work has demonstrated that intergenic V(D)J rearrangement, a process referred to as trans-rearrangement, occurs at an unexpectedly high frequency. These rearrangements generate novel V(D)J combinations which could conceivably have some role in the normal immune system, and since they probably arise through chromosomal rearrangements akin to those associated with lymphoid neoplasia, the...