Stibinidene and Bismuthinidene as Two‐Electron Donors for Transition Metals (Co and Mn)

The reaction of stibinidene and bismuthinidene ArM [where Ar=C₆H₃‐2,6‐(CH=NtBu)₂; M=Sb ( 1 ), Bi ( 2 )] with transition metal (TM) carbonyls Co₂(CO)₈ and Mn₂(CO)₁₀ produced unprecedented ionic complexes [(ArM)₂Co(CO)₃]⁺[Co(CO)₄]^? and [(ArM)₂Mn(CO)₄]⁺[Mn(CO)₅]^? [where M=Sb ( 3 , 5 ), Bi ( 4 , 6 )]. The pnictinidenes 1 and 2 behaved as two‐electron donors in this set of compounds. Besides the M→TM bonds, the topological analysis also revealed a number of secondary interactions contributing to the stabilization of cationic parts of titled complexes.     

Analysis of LK-157 in Plasma by LC–MS–MS: Application to Studies of Pharmacokinetics and Degradation Pathways in Rats and Dogs

Multiple-species plasma-stability testing and pharmacokinetic studies in rats and dogs were performed on LK-157, a novel 10-ethylidene tricyclic carbapenem and potent inactivator of β-lactamases of classes A, C, and D. An LC–MS–MS method was developed and validated for analysis of LK-157 in rat and dog plasma. Separation was achieved on a C₁₈ column by gradient elution. The lower limit of quantification for LK-157 in plasma was 50 ng mL^?1. Intra-day and inter-day precision were <12.5 and <11.8%, respectively. When degradation of LK-157 was assessed in buffer solutions and in rat, dog, and human plasma, the compound was found to be stable in pH 7.0–9.0 phosphate buffer for 24 h at room temperature, and in human plasma for 60 min at 37 °C. The stability of LK-157 was species-dependent. Results from study of in vitro metabolism showed that the enzymes liver cytochrome P450 and uridine diphosphate glycosyltransferase do not metabolize LK-157. LC–MS–MS was also successfully applied to a pharmacokinetic study. The pharmacokinetics of LK-157 after bolus intravenous administration (10 mg kg^?1) to Wistar rats and Beagle dogs was described by a two-compartment pharmacokinetic model. Human pharmacokinetic data were extrapolated from dog pharmacokinetic data. The extrapolated human terminal-phase half-life of LK-157 was 2.3 h. Stability and pharmacokinetic data for LK-157 are in agreement with results for other inactivators of β-lactamases.     

Investigating out-of-specification test results of chemical composition based on metrological concepts

A metrological background for investigating out-of-specification (OOS) test results of chemical composition is discussed. When an OOS test result is identified, it is important to determine its root causes and to avoid reoccurrence of such results. An investigation of the root causes based on metrological concepts would be beneficial. It includes (1) assessment of validation data of the measurement process, (2) evaluation of the measurement uncertainty contributions, and (3) assessment of metrological traceability chains critical for measurement parameters and environmental conditions influencing the test results. The questions, how can the validation data be applied for this investigation, and how can measurement uncertainty contributions and/or metrological traceability chains change a probability of OOS test results, are analyzed.     

Estimation of W0/WT ratio for cloud-to-ground lightnings

The aim of this paper was to obtain the quantitative estimation of the W₀/W_T (initial electric energy/atmospheric parameter of a surrounding medium) ratio for CG lightnings initiated with a stepped leader process. The results of analytical and numerical models show that the W₀/W_T ratio for CG lightnings spans the range of approximately two orders of magnitude 20 ≤ W₀/W_T ≤ 2000. The results also suggest that CG lightnings differ significantly from small-scale discharges in the laboratories: the thundercloud CG lightnings occur at considerably lower initial electric energy, higher atmospheric parameter of the surrounding medium or a combination of both.     

Performance evaluation of adaptive meshing algorithms for fluorescence diffuse optical tomography using experimental data

Fluorescence diffuse optical tomography (FDOT) is a computationally demanding imaging problem. The discretizations of FDOT forward and inverse problems pose a trade-off between the accuracy and the computational efficiency of the image reconstruction. To address this trade-off, we analyzed the effect of discretization on the accuracy of FDOT imaging and proposed novel adaptive meshing algorithms for FDOT in a series of studies. In this Letter, we apply these new adaptive meshing algorithms to FDOT imaging using real data from a phantom experiment to demonstrate the practical advantages of our algorithms in FDOT image reconstruction.     

Extraction of antioxidants from plants using ultrasonic methods and their antioxidant capacity

The analytical method based on the HPLC coupled with UV detection (HPLC‐UV) for the determination of selected antioxidants (i.e. esculetin, scopoletin, 7‐hydroxycoumarine, rutin, xanthotoxin, 5‐methoxypsoralen and quercetin) in plant material was developed. Two ultrasonic extraction methods for the isolation of these compounds from the plants such as Mentha longifolia L., Mentha spicata L., Ruta graveolens L., Achyllea millefolium L., Plantago lanceolata L. and Coriandrum sativum L. were used. Both of these methods, i.e. ultrasonic probe and ultrasonic bath, were optimised and compared to each other. For the proposed HPLC‐UV method LOQ values in the range from 22.7 (xanthotoxin) up to 97.2 ng/mL (rutin) were obtained. For all extracts the antioxidant capacity based on the reduction of free 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical was also determined. Obtained results ranged from 10.11 up to 73.50% of DPPH radical inhibition.     

Analysis of Polymer Dynamics by NMR Modulated Gradient Spin Echo

NMR modulated gradient spin echo method, which allows the quantification of polymer segmental displacement via the measurement of the velocity autocorrelation, requires the formulation of theoretical predictions in the frequency domain in order to test their validity. We worked out the velocity autocorrelation spectrum of the segmental motion according to the Rouse and the tube/reptation model to compare it to the experimental results obtained by the new NMR technique. The analysis of polybutadiene shows the segmental velocity autocorrelation spectrum typical for the reptation-like motion of polymer in a “tube”. The measurement of bulk water indicates a kind of Rouse motion in a network of hydrogen bonds.     

On Existence of Solution, Oscillatory and Non-Oscillatory Properties of Delay Impulsive Differential Equations Containing ‘Maximum’

In this paper, we determined the criteria for the existence of solutions for delay impulsive differential equations containing ‘maximum’ (DIDEM) using the Morales’ fixed point theorem. An impulsive analogue of the Gronwall-Bellman’s inequality with deviating argument is also considered. Some results on the oscillation and non-oscillation of solutions of the (DIDEM) are also obtained. Applications of the oscillatory results obtained are made to four non-linear examples one of which is a military model and upper bounds found for the solutions of the impulsive Fitzhugh-Naguno model and an impulsive nonlinear control system.