Degradation kinetics of telithromycin determined by HPLC method

The degradation kinetics of the antibiotic telithromycin using a stability-indicating high-performance liquid chromatography (HPLC) method is demonstrated. The photodegradation is performed by UVC lamp-254 nm (15W), installed in a chamber internally coated with mirrors, where telithromycin solutions prepared from coated tablets are placed in quartz cells. To promote oxidation, the reaction between the telithromycin solution and 3% hydrogen peroxide solution is carried out. The kinetics parameters of order of reaction and the rate constants of the degradation are determined for both conditions. The degradation process of telithromycin can be described by first-order kinetics under both experimental conditions used in this study. The results reveal the photo and oxidation lability of the drug and confirm the reliability of HPLC method for telithromycin in the presence of its degradation products.     

Measurement of the differential cross section for πp → πn around the Δ(1232) resonance and test of the charge independence principle

Differential cross sections for the charge-exchange reaction of π⁻ on protons in the region of the Δ(1232) resonance (128 MeV T_π⁻ 246 MeV) are reported. Measurements were performed by detecting the neutron with a time-of-flight technique. The neutron counter efficiency was measured over the entire energy range. Particular care was devoted to eliminating possible sources of systematic error. Statistical errors are of the order of 4%, total errors of the order of 7%. The experimental results are in fair agreement with the most recent phase-shift analysis. Our data satisfy the triangle inequality. An analysis based on recent phase-shift values does not favour violation of charge independence.     

Elektrische Leitfähigkeit eines vollionisierten Plasmas in einem äusseren Magnetfeld

Ohne Zusammenfassung     

Enhanced absorption in the magnetoacoustic resonance with increasing rf power

Strong damping of the magnetoacoustic resonance, excited with moderate rf power in a low-density helium and argon plasma is investigated. Enhanced absorption of the wave and higher turbulence is observed wiht increasing rf power.     

Green synthesis and antibacterial activity of chalcogenoesters

Herein, we present a new variation for an eco-friendly methodology for the synthesis of chalcogenoester in good-to-excellent yields in a short time, with an easy work-up/purification step, and in a greenest methodology, affording the minimum generation of solid and liquid waste, in comparison to that described in the literature. Additionally, some selected compounds were evaluated as antimicrobial agents, showing moderate activity against a variety of microorganisms including the K. pneumoniae, P. aeruginosa and also some selected fish pathogenic bacteria.     

Real‐time feedback from iterative electronic structure calculations

Real‐time feedback from iterative electronic structure calculations requires to mediate between the inherently unpredictable execution times of the iterative algorithm used and the necessity to provide data in fixed and short time intervals for real‐time rendering. We introduce the concept of a mediator as a component able to deal with infrequent and unpredictable reference data to generate reliable feedback. In the context of real‐time quantum chemistry, the mediator takes the form of a surrogate potential that has the same local shape as the first‐principles potential and can be evaluated efficiently to deliver atomic forces as real‐time feedback. The surrogate potential is updated continuously by electronic structure calculations and guarantees to provide a reliable response to the operator for any molecular structure. To demonstrate the application of iterative electronic structure methods in real‐time reactivity exploration, we implement self‐consistent semiempirical methods as the data source and apply the surrogate‐potential mediator to deliver reliable real‐time feedback. © 2015 Wiley Periodicals, Inc.     

Tri- and hexavalent mannoside clusters as potential inhibitors of type 1 fimbriated bacteria using pentaerythritol and triazole linkages

Several oligomannoside clusters having a hundred-fold increase in affinities toward E. coli were synthesized by Cu(I)-catalyzed [1,3]-dipolar cycloadditions using pentaerythritol scaffolds bearing either alkyne or azide functionalities.