Theoretical study of Diels-Alder reactions between cyclopentadiene and 2-aryl-4,6-dinitrobenzotriazole 1-oxides

This work deals with the theoretical study of Diels-Alder inverse and normal electron demand reactions. Based on various calculation methods such as SCF/6-31G and DFT/B3LYP with the standard basis set 6-31G, we discuss the possibility of reactions between cyclopentadiene with a series of 2-aryl-4,6-dinitrobenzotriazole 1-oxides from a thermodynamic perspective.     

Simultaneous quantification of levofloxacin,pefloxacin, ciprofloxacin and moxifloxacin in microvolumes of human plasma using high‐performance liquid chromatography with ultraviolet detection

Levofloxacin, pefloxacin, ciprofloxacin and moxifloxacin are four fluoroquinolones used in the treatment of serious bacterial infections. The antibacterial activity of fluoroquinolones is concentration dependent. Therefore, therapeutic drug monitoring in daily clinical practice is warranted to ensure the therapy's efficacy and prevent bacterial resistance. The purpose of the present study was to develop a method using high‐pressure liquid chromatography with an ultraviolet detector for simultaneous quantification of these four fluoroquinolones in human plasma. A 50 μL aliquot of plasma was precipitated by 200 μL of methanol using gatifloxacin as internal standard. The chromatographic separation was performed on a Kinetex XB‐C₁₈ column using a mobile phase composed of a mixture of orthophosphoric acid 0.4% (v/v), acetonitrile and methanol at a flow rate of 1.2 mL/min. Dual UV wavelength mode was used, with levofloxacin and moxifloxacin monitored at 293 nm, and pefloxacin and ciprofloxacin monitored at 280 nm. The calibration was linear over the ranges of 0.125–25 mg/L for levofloxacin, 0.1–20mg/L for moxifloxacin and 0.05‐10 mg/L for both pefloxacin and ciprofloxacin. Inter‐ and intra‐day trueness and precision were <13% for all the compounds under study. The proposed method was simple, reliable, cost‐effective and suitable for therapeutic drug monitoring or pharmacokinetics studies.     

Linear codes from support designs of ternary cyclic codes

Designs, Codes and Cryptography - For a long time, the literature has demonstrated that designs and codes are exciting topics for combinatorics and coding theory. Linear codes and t-designs are, in...     

Compressed exponential form for disordered domain wall motion in ultra-thin Au/Co/Au ferromagnetic films

Magnetization reversal in ultra-thin Au/Co/Au films deposited on single crystal silicon (1 0 0) was investigated using Kerr microscopy. In the considered ultra-thin Co films, with a thickness between 0.7 and 1 nm, the coercivity and magnetic anisotropy decrease with decrease in cobalt layer thickness and the magnetization reversal dynamics is dominated by disordered domain wall motion. An analysis of the observed magnetization reversal dynamics is proposed, starting from the Fatuzzo-Labrune model. We show that the relaxation curves of these samples are well described by a function obtained by a technical transformation of Fatuzzo-Labrune model in the regime dominated by domain wall motion.     

Tetrathiafulvalene based electroactive ligands and complexes: Synthesis,crystal structures and antifungal activity

The synthesis of two tetrathiafulvalene-appended pyridinehydrazone pyrimidine ligands, namely (Z)-4-(2-((5-([2,2′-bi(1,3-dithiolylidene)]-4-yl)pyridin-2-yl)methylene) hydrazinyl)-6-chloropyrimidine L1 and (Z)-4-(2-((6-([2,2′-bi(1,3-dithiolylidene)]-4-yl)pyridin-2-yl)methylene) hydrazinyl)-6-chloropyrimidine L2 is described. Ligand L1 was reacted with cobalt(II) to yield a cationic metal complex [Co(L1)₂] while ligand L2 was reacted with zinc(II) to afford a neutral metal complex [ZnL2Cl₂]. The crystal structure analysis of [Co(L1)₂] indicate that Co(II) ion is coordinated by six nitrogen atoms from two perpendicular ligands while in [ZnL2Cl₂], Zn(II) is coordinated by two chlorine atoms and three nitrogen atoms. The electrochemical behavior indicate that ligands L1 and L2 and the zinc(II) complex are suitable fort the preparation of crystalline radical cation salts. Finally the determination of MIC₈₀ values against C. albicans, C. glabrata, C. parapsilosis, C. krusei and E. dermatitidis revealed that the cobalt(II) metal complex [Co(L1)₂] is active against all the studied fungi.     

Evaluation of different machines used to quantify genetic modification by real-time PCR

Quantification of genetic modification (GM) is often undertaken to test for compliance with the European Union GM labeling threshold in food. Different control laboratories will often use common validated methods, but with different models of real-time PCR machines. We performed two separate ring trials to evaluate the relative precision and accuracy of different types of real-time PCR machines used to quantify the concentration of GM maize. Both trials used dual-labeled fluorogenic probes for quantification. The first ring trial used separate GM and reference assays (a single fluorescence channel), and the second used a combined duplex assay (two simultaneous fluorescence channels). Five manufacturers and seven models--including a 96-well microtiter-plate, rotary, and portable machines--were examined. In one trial, the machine used had a significant effect on precision, but in the other it did not. Overall, the degree of variation due to the machine model was lower than other factors. No significant repeatable difference in accuracy was observed between machine models. It was not possible to use sufficient replication of machine type in each laboratory to examine all sources of variation in this study, but the results strongly indicate that factors other than machine type or manufacturer (e.g., method or laboratory) contribute more to variation in a GM quantification result.     

Genetic diversity and haplotype structure of 21 Y‐STRs,including nine noncore loci,in South Tunisian Population: Forensic relevance

Y chromosome STRs (Y‐STRs) are being used frequently in forensic laboratories. Previous studies of Y‐STR polymorphisms in different groups of the Tunisian population identified low levels of diversity and discrimination capacity (DC) using various commercial marker sets. This definitely limits the use of such systems for Y‐STRs genotyping in Tunisia. In our investigation on South Tunisia, 200 unrelated males were typed for the 12 conventional Y‐STRs included in the PowerPlex® Y System. Additional set of nine noncore Y‐STRs including DYS446, DYS456, DYS458, DYS388, DYS444, DYS445, DYS449, DYS710, and DYS464 markers were genotyped and evaluated for their potential in improving DC. Allele frequency, gene diversity, haplotype diversity (HD), and DC calculation revealed that DYS464 was the most diverse marker followed by DYS710 and DYS449 markers. The standard panel of 12 Y‐STRs (DC = 80.5%) and the nine markers were combined to obtain DC of 99%. Among the 198 different haplotypes observed, 196 haplotypes were unique (HD = 99.999). Out of the nine noncore set, six Y‐STRs (DYS458, DYS456, DYS449, DYS710, DYS444, and DYS464) had the greatest impact on enhancing DC. Our data provided putative Y‐STRs combination to be used for genetic and forensic applications.